Ben1098

Quick test. Sounds like the fuel pump is not keeping up with demand. After the 30 sec or so run time, and starts to die, give it a wiff of starter fluid and see if it recovers........fuel starved. Key OFF wait 5 sec or so....Key ON only------no start position. The fuel pump is turned on for about 5 sec to PRIME/PRESSURIZE fuel rail.....signal is from the ECM.......wait it out for time out......then start. Listen for the short prime time running. Start.....ECM should now keep the fuel pump full time. Put a test light on the pump connector (clamp to Gnd) and check for 12v. Then reverse the clamp connector from Ground to a hot +12v.....you can now check for a good ground at the connector.

HS800.....should be HS500. See Motorcycle Doctor store....has several units for the HiSun 500. While you are talking, confirm the flywheel P/N also. Talk about going 20 steps backwards...............been there as we usually ended up with the dogs after $$$$$$$$$$$$$$$$ wasted and they did NOT usually get the "good" parts back as there are no returns on electrical. My personal best was a Honda 350 ATV. Dead IGNITION. 3 H shops, 1 Independent. Shotgun parts. Had thick folder. From Chicago area. Drove down and stood in line a busy (pulled up front) Sat AM. Seen ALL parts for the IGN replaced shop WO parts list. Clue: Asked what he used it for. IDNR food plots. OH! Took clip lead and meter to his PU. T/S in the bed......first guess at the sales counter was right. Run. Boss didn't even know I left. He was charged for 7 minutes. MY take on the whole story...............exhaust cam wear and low compression was the initial killer. CHOW.....hope you finally win. BEN

20 sec video. Hit play. Time bar slider moves. Any tap on the blank screen throws me into full screen. no audio, no video. Times out---done. UTube video. I see the white mark "flashing" at the 90 deg point (9 o'clock with 12 being the cast index in the head). Confirm the cam lobes are down (valves closed) when the white mark on cam gear is at the top (12 o'clock) position and piston is at the very top TDC. If you got that, you are timed mechanically. If that is correct, you have one of three things going on: 1. The flywheel buttons or tabs "missing or skip tab" is off relative to the flywheel center keyway....which is locked to the crankshaft. The TDC was confirmed with the Cu wire test touching the top of the piston. Inside, the 18 knuckle poles stator (3 Ph. gives 6 magnet pairs) are independent of tabs on the rim...charging only. 2. Wrong part # ECM (DElLPHI MT05).......The pin outs are all the same. Software maps and advance curves are what change per application.. OR 3. The MT05 is for a 90 deg V twin motor w/ dual coil outputs.......... example is the KAW and KOHLER engines used on high end Zero-Turn mowers. The MT05 has 2 coil output pins: COIL A is pin J1-10 w/ J1 is Grey and COIL B is Pin J2-01 w/ J2 is Black Prior techs swap the pins???? eBAY Store of MOTORCYCLE DOCTOR. He carries HiSun parts and P/N. You have 2 parts to check out. Seen he has helped others on this forum. BEN

Dimmed my monitor............I SEE......Your timing is out in the weeds like 90 deg at the cam=180 deg at the crank. Cam gear is upside down to the cam punch mark. Same as I saw in your still a couple posts back. Revisit the cam gear installation. Before taking the cam gear off, rotate the engine to the TDC (with painted cam gear at the casting mark) as before. The rockers should be up (valves closed). Look into the rocker valve adj lid hole at the rockers. The cam lobes (BOTH) should be down....no lift on the rocker and the valves closed. For this timing, you have to be in OVERLAP with the Exhaust going off and the Intake coming on at the second TDC of the 720 deg rotation per cycle. Ain't no 2 stroke. WARNING: This is sorta dangerous right now.......you got some spring energy wanting to eat your fingers if you remove the cam gear bolts. Rotate the crank until the cam lobes are down (COMPRESSION) and the valve springs are unloaded. Now safe to pull cam bolts. Check for the punch mark on the end of the cam.......should be pointing to the head casting timing mark. Match the cam gear, etc. BEN

Saw the UTube vids. Notice the "stall" and hard first crank turn over.............your compression release is NOT working.....starter is good and powering thru to get it spinning. I could not determine the flashes of the timing light from the video. Back to the Cu wire and finding the TDC mark. Degrease and put in a small white dot to mark (and be easier to quickly spot) just like the cam. Determine that this is still the case......no timing chain jump. Normally, RICE BURNER (old slang for the Japan Mfg, like LIMEY for British and CHINO is for HiSUN) machines cranks have 4 marks. TDC-----piston is at the top and rocks up and down as this timing mark is rocked back and forth with the crank. Cam gear dimple (now painted) will be at the cast notch at the top. F line......static timing line for low RPM (and cranking).......the ignition spark time......around 8 deg BTDC....have to manually turn backwards to this line from TDC. FULL ADVANCE spark line (dual parallel lines). The reason for the 2 lines close together......the high RPM advance is say 28 deg BTDC but there is some tolerance so the one mark might be 26 deg and the other 30 deg. Your cam gear has 46 teeth. Crank gear has 23 teeth........the 2:1 ratio required for the cam to run at 1/2 the crank RPM. Knowing this, you can do some quick math and determine each tooth at the cam is close to 7.8 deg each of the cam.....and close to 16 deg of the crank. The static (idle=8 deg) timing mark will have the cam gear rotate backwards about only 1/2 tooth at the cast head timing mark. The double parallel lines (FULL advance at 28 deg crank) would be close to the 2nd tooth back.................was used to check if the spark advanced as RPM increased to say 2200 RPM. You are describing the TDC single line and after you rotate backward the 0.50" the double lines.........STATIC (8 deg BTDC advance) timing mark.....about 1/2 tooth on the cam. Leave the spark plug out (pull the fuel pump connector) and repeat the timing light test-----will only have the plug hole whistle. WHAT LIGHTS UP and WHERE???? SHOULD have the cam's white dot move slightly BTDC....and of course the wasted spark. Do it in reduced light so the mark pops out on the video so I can see where the ECM is firing the IGNITION. BEN

WHOA THERE!!!!!!!!!!!!!!!!!!!!!!! Yes, I can do UTube vids. The pics of timing looks weird. You need another paint mark on the cam gear.......................the FIRE mark on the flywheel at the notch location transferred to the cam gear.. The flywheel in the first pics looks right with all the pick up coil buttons or tabs. You need to locate the "F" mark on the flywheel. Timing on most motors are in the 8-14 deg BTDC area.......the static timing mark at idle. As the engine RPM increases, the flame front cannot be at the same position away from the piston.....it takes time....very short time....for the flame front to reach the piston dome. The timing has to start sooner so the ADVANCE CURVE (caused by flyweights in the old points engines) or a Map in ECM units...........will slide from the idle of say 8 deg to something like 28 deg BTDC. Back to the flywheel. Hand turn the flywheel to the TDC mark used for cam timing. Now, slowly rotate the crank BACKWARDS. About 8 deg back, you should see a line with an F.....the idle fire timing mark. Mark the cam gear a second time at the head casting arrow. This will be the point where the timing light will flash at idle. Rotate backwards even more until you see 2 lines.......this if the full advance point of say 28 deg. This will slide into view when getting above say 2200 RPM. Not needed now. Repeat the timing light at the cam......your new or 2nd paint mark should be at the casting arrow.

HiSun may have changed the little mini cam rod profile shape so that the now NOT fully CCW disk rotation allows the pin to drop back into the shaft and not affect the decompression function. 5 years ago that was a bad batch of flyweights. Running Engr Changes are a problem out in the field. This engine has run before BUT it probably has had many hands in the soup. With these shop jumpers, sometimes you had to go back 20 steps just to get back to GROUND ZERO. How did a timing light check out? HINT: You can just shine the timing light on the cam and watch the paints at the cam.....BUT you will have a spark at the painted cam timing mark AND an "extra" flash when the cam is 180 out on the other gear mounting bolt. Anyways, your timing appears to be correct. You have good compression numbers. Lets drop back and check the spark plug. After cranking is the plug wet with fuel? These machines hate Chumpion plugs. Go with a new NGK....nothing fancy........ $$$$ tips not req'd. There were 2 versions of the injectors----the slobbering 2 hole and the spray 3 holer. Fuel pump pressure should be around 40 PSI. Exhaust restriction....like did mud dobbers make a summer home in the muffler? Mouse house in the air box and/or plumbing? Need good air flow in and out. Strip it back to just the basic engine. Pull the fuel pump connector.....removes possible fuel rich condition and ECM control of fuel management. Good known new dry spark plug.....use compressed air to dry the top of the piston and combustion chamber if flooded or wet down. Remove the air box to TB plumbing rubber tube.........just the throttle body and without any fuel. Manually turn the engine over until the exhaust valve is opened fully. Blow air into the spark plug hole like you are doing a leak down test. Does the air come out of the muffler with a clean unrestricted rush of air? Motor is just an air pump---has to have a good flow. Rotate engine until intake valve is open....same test cannot be done here as the MAP sensor doesn't like that. Open the throttle body (gas pedal) and direct the air at the spark plug hole....hear a good flow backwards out the TB? Combustion chamber has no residual fuel. Crank. Did it try to start? Shouldn't. Give the intake TB a short shot of starter fluid. You should at least get a try to fire and run.....dies after go juice used up......if the engine is solid, Start adding parts back to the system. Connect the air box rubber tube to the TB. TEST. Add back the air box with the lid removed. TEST Crank and supply the go juice as fuel to the air filter body. Give it longer bursts of go juice to see if engine will run for say 3-5 sec and die. Connect the fuel pump connector. KOn (key on) 2 -3 sec pump run to pressurize the fuel rail/tubing. Pull the fuel pump connector again. What this does is give the ECM a chance to fire it over BUT if a problem like too rich, it will not be "spoiled" again after the fuel rail pressure drops back....i.e. no more fuel. Should have a short fun and die. Short burst of go juice at air filter....same start and die? Looking for same results from before with longer bursts of go juice. Reconnect the fuel pump connector....KOn......TEST. Short burst of go juice. Fire up and continue to run or die? Need this info to go further. Try these things first............gets you to the big Y in the road..................you might not like the one path as it gets into Delphi MT05 ECM and it's inputs. Tell you what. The Delphi unit has GOOD online information and gives the I/O pinouts on a diagram. Look further back past the front section Engr Secs and look for the BLACK and GREY CONNECTOR drawings AND the full connection "wiring diagram" page....great if you also own a KAW lawn mower engine---uses the same basic module.

I assume the new latest pics are the new cam and head assy????? It has a problem. Poor mfg process information (instructions and drawings) never really go away. They always pop back up like the turd they are. I was flown to Mexico for multiple "mistakes" and to T/S with a "fix and rework"---clean up the build information----and only to find the same problem pop up again 6 months later from the sister supplier, This problem was on both Yamaha Rhino and Hisun cam assys a good 5 years ago. We had Massimo. Another shop had Yamaha. They chased a mystery problem to the cam assy. My new cam assy arrived (with the same runability problem) in the new uncrated unit.. I did the carbide burr air tool hand mill job on both sets. EXCESS WELDED WEIGHT GONE. Other shop has same problem. His flyweights had all the same machining, stamping marks...with welds identical.....the same sub supplier. My reworked flyweights were given away to fix the Rhino. Since you have the old cam, mark the flyweights to MATCH their wear "home" location. Remove and you should see the rub marks where the little disc hits the rear welded/attached weights. For the fun part: 1. Hold the whole cam assy and put the button head pin that sticks thru further to the inside by the exhaust cam lobe DOWN. Gravity is your friend. 2. Put your thumb on the button-----should push in below the cam "shaft" profile----as in not the lobes profile----Rotate the disk and the mini cam will push up the button. 3. Reverse and the button will retract again into the cam shaft area. See how the system works. 4. Pull out the small disk with the 2 flyweight engagement pins. 5. The "rod" attached (with the dogleg bend) is the minicam within the cam----used to push up the button pin that hits the extra tab on the exhaust side of the big valve cam. 6. With this pin out, the button can now fall into the hollow main cam center. Gravity----set down cam button down. If it falls to the center, no big loss. Just a pain to reinsert it into hits hole....ship in a bottle syndrome. 7. You should now see why the your adjustment is wrong. Rotation of the of the flyweights, rotates the small dime sized disk, which rotates the dogleg rod inside the hollow cam. 8. YUP, the end of the dog leg is what pushed the pin out further to engage the cam. BUT. if the small disk cannot fully rotate backwards, the button protrudes out too much and now does a compression release. 9. Your thinking now, why not just make the disc smaller in diameter........NOPE, not enough meat left for the pin hole wall thickness. BEN EXTRA correct operation Engine stopped. The springs pull the sling flyweights back. The mini cam (all you can see is the disk with the 2 pins) will push the button up and hold the exhaust valve slightly open.....only while the rocker's extra "tab"-----not the cam lobe------ is on the button.......after which time the regular exhaust cam lobe will them rub it's normal slipper pad. The is the decompression release. You don't want all fuel/air to escape.....only to unload the stalling hit the starter would take if it was not there. After the starter gets it spinning good, the "slightly open" time is less and less.....now almost up to full compression. Hint: It takes time for the fuel/air being compressed to leak off out the slightly open exhaust valve. Rotate faster and faster, less can get away every rotation with the same amount of cam button lift. Hope that makes sense. Rotation of the cam (faster than crank speed at some point) will sling the the weights out and the small disk will rotate (against the weak springs) via the 2 pins and retract the small pin........the full time run compression position. The disk has to rotate say some 90 deg between run (retracted pin button) and dead crank start positions. The extra metal limits the guessed 90 deg to say only 45 deg. Look at the last or lowest pic. Notice the 2 pins are NOT in the bottom of the V. If they were, the timing punch mark in the small disk would almost be covered as the disk rotated CCW some more. Look at the lower flyweight (easiest to see in the pic but both are excess material) and see the welded metal flyweight tab is rubbing the small disc. This tab needs to have the same profile of the main body stamped flyweight part. Not placed correctly in the jig when welded. I just scrolled back to your original post about the cam timing. The old flyweights looked off also but not as bad. With the pin constantly rubbing the it's rocker "tab", it would eventually grind out the softer tab and make a grove cut and then the compression release didn't work. Take this assy and do a thumb on the button test and rotate the small disk back and........the button should extend out of the cam and retract full below the shaft profile. They were stinkers. Cheap grease in the rear end. Heads not torqued down....head gasket leak......push out anti-freeze...some toasted or cracked the head. Purging the air after head work. Gasket maker drying out (got hard) and not sealing the rear facing drive shaft. Always feel the hoses for hot ones (means you have coolant flow). Stupid mini fuel tank...puked on hard steep hill climbs. Buried series snubber diode (opens=no fan=very BAD) buried in the wiring harness for the radiator fan. Soft 4WD diff lock up you never shift on the fly. Replacement cylinders the cam chain rubbed the Al inside the chain chute. Heat shields not deburred that cut into the O2 sensor heater wire and kills engine only in FWD gears....REV runs just fine. BTW, I own one. Bought a swimmer left by drunks at the river so they would not get a DWI----of course they was kind enough to leave the keys in the IGN overnight. I figured I knew all the bad stuff, so it was my entry level SXS. Never bought a vehicle that wasn't SICK. Old farm boy....fixed our own stuff. Gotta go.

I assume the new latest pics are the new cam and head assy????? It has a problem!!!!!!!!!!. Poor mfg process information (instructions and drawings) never really go away. They always pop back up like the turd they are. I was flown to Mexico for multiple "mistakes" and to T/S with a "fix and rework"---clean up the build information----and only to find the same problem pop up again 6 months later from the sister supplier, This problem was on both Yamaha Rhino and Hisun cam assys a good 5 years ago. We had Massimo. Another shop had Yamaha. They chased a mystery problem to the cam assy. My new cam assy arrived (with the same runability problem) in the newly uncrated unit.. I did the carbide burr air tool hand mill job on both sets. EXCESS WELDED WEIGHT GONE. Other shop has same problem. His flyweights had all the same machining, stamping marks...with welds identical.....the same sub supplier. My reworked flyweights were given away to fix the Rhino. Since you have the old cam, mark the flyweights to MATCH their wear "home" location. Remove and you should see the rub marks where the little disc hits the rear welded/attached weights. For the fun part: you can do it. 1. Hold the whole cam assy and put the button head pin that sticks thru further to the inside by the exhaust cam lobe DOWN. Gravity is your friend. 2. Put your thumb on the button-----should push in below the cam "shaft" profile----as in not the lobes profile----Rotate the disk and the mini cam will push up the button. 3. Reverse and the button will retract again into the cam shaft area. See how the system works. Flyweights pulled in by springs...sling out with rotation speed.....disengage the decompression pin.....at engine stop, the springs retract the weights but cannot due to the excess welded weight material profile rub with the small disk. 4. Pull out the small disk with the 2 flyweight engagement pins. 5. The "rod" attached (with the dogleg bend) is the minicam within the cam----used to push up the button pin that hits the extra tab on the exhaust side of the big valve cam. 6. With this pin out, the button can now fall into the hollow main cam center. Gravity----set down cam button down. If it falls to the center, no big loss. Just a pain to reinsert it into hits hole....ship in a bottle syndrome. 7. You should now see why the your adjustment is wrong. Rotation of the of the flyweights, rotates the small dime sized disk, which rotates the dogleg rod inside the hollow cam. 8. YUP, the end of the dog leg is what pushed the pin out further to engage the cam. BUT. if the small disk cannot fully rotate backwards, the button protrudes out too much and now does a compression release. 9. Your thinking now, why not just make the disc smaller in diameter........NOPE, not enough meat left for the pin hole wall thickness. 10. Reassy is just pushing back in the dogleg rod (with the decompression button facing down) and the punch mark up as used in the timing mark. BTW, use a small 6 inch scale to use as a straight edge to line up the cam bolts, alignment dimple and the cast timing mark in the head. BEN

You added some more info while I was typing, You have one of the flyweight sets that do not retract fully. This is an old problem form 5 years ago. Look at the 2 pins on the dime sized disk...........Notice the flywheel pin notches are slightly open.....not sitting in the bottom of the "v" groves. The flyweights are made of 2 parts.....the outer notched plate and the extra welded on weight tabs underneath. The small disk is holding the welded on weights about half open....inside circle is RUBBING against the dime sized disk on it's outer diameter. You need to grind out the excess material for the new one you bought. Storm front line coming. Making it short.......look at the used old flyweights.....check clearance/rub are.....if better trade the flyweights....later.

The inner bonded magnets are for the charging system. Nothing to do with the ignition unless the AC signal is used as a check by ECM to see if the engine is rotating. The outer metal tabs are just that....metal (steel) tabs for the pick up coil's internal magnet. Think of the keeper bar for a kids toy horseshoe magnet. The steel tabs react with the magnet inside the coil...sorta a make break for the magnetic flux.. The changing magnetic flux (starting with a change at the leading edge and a reverse at the trailing edge) generate the + and - pulse spikes. Your screw driver has some residual magnetism....it will probably pick up small screws. Try another tool. The ignition is a wasted spark system. The crank turn over 2 times per full stroke......since it doesn't have a cam sensor, just like an B & S lawnmower engine with points just run of the crankshaft....spark every rotation of the crank.....be it COMPRESSION or EXHAUST. Spin over with a timing light and check the painted timing mark (close to TDC). Coil resistance is in the ball park. At least it is not an open circuit. My old computer video player cannot play your videos....my bad I guess. I cannot view for a guess what is going on. Only set the timing marks per earlier reply. They will run a couple of teeth off, but poorly. You written description makes me think the exhaust valve is not adjusted correctly. This can happen if the valve was adjusted on the compression release button location....... and was out. This will result in the valve adjustment being wrong. Turn the engine over slowly by hand and bring the piston to TDC on Compression (both valves closed). Check for valve clearance. The decompression pin will be holding the valve slightly open. Turn backwards and feel for the valve to close again....this takes the load off the decompression cam actuator. Push the flyweights on the cam to the run position (rotates the small dime sized inner disk) and hold open while rotating to TDC AGAIN. This is what happens after the cranking speed increases after firing up and rotating to the idle speed. Check your clearance at the TDC this time. Adj if off. If you release the flyweights, they will sorta "stay" in the open position. The flyweight springs cannot physically push the exhaust valve open for decompression. There is a small inner cam that pushes the actual pin out before the valve rocker hits this decompression pin. Slowly rotate the engine backwards and the flyweights will fully retract. Slowly rotate forward and the exhaust halve will slightly open this time......lowering the compression pressure. These flyweights should "held" by the valve train pressure. Do a compression test again.......Should be at least 120 PSI with a correct compression gauge. Hope this explains better the decompression system.

Your pics are of the outer rim of the flywheel. The tabs in your pics are for the pick up coil......ECU senses the + and - pulses as the square buttons pass under the "face" of the PU coil. You have a "Missing Pulse" set up here. Others machines, like 4 wheelers, will only have a Single tab for a single cylinder and a V engine will have 2 with it's marks line up for IT'S TDC when they pass under the coil face. The pick up coil has a round bar magnet inside and wire wound around the bar magnet. Take the PU coil and put a small blade screw driver on the face...feel the pull of the PU coil internal magnet. MAGNETS Not shown in your pictures.......they are on the inside of the flywheel. They will be blocks (sometimes glued to the inside walls. Some had failures with unbonding but it will destroy the stator knuckles......these are used for charging the battery using the regulator....3 Phase......thus, these are the 3 yellow (white) wires that go to the Regulator. These have nothing to do with the timing tabs on the outer rim. Test the magnet(s) inside by taking say a 3/8" extension and roll around the inside.....will pull/stick at the gaps in the magnet bodies. You can see if the bonding has a crack.

Past experience for a random (as in your heat soak cycle-----engine hot and will come back to life again with some cooling) is the pick up coil. Next is the ignition coil. Use a spark gap tester and watch the spark quality and/or hit and miss or dead. The really OLD timing lights (60's) used just a dim neon tube. A weak spark would result in a really dim or non flash. Also, Snap-On sold a handheld spark voltage tester with flashing LED indicators and a thumb wheel voltage trip point selector. Lab scopes give a visual check if you know a friend who has one with the spark pick up clamp. STORY: I have had some pick up coils that would take forever to fail and then heal BEFORE you could pull the connector and connect an ohm meter to check for an open coil instead of the spec'd resistance. That one was solved by using a DPDT switch to check the resistance right as it died......could watch it "heal" again in less than 5 seconds. It had been thru a bunch of shops before me.

BTW.......rocker shafts are removed by screwing in an 8mm??? bolt and then pulling on the bolt head and/or slide hammer. Rockers are then removed. You first need to check the possible sheared crankshaft key. Take a soft copper wire about 16" long and put a finger loop on one end. Stick the wire into the spark plug hole and rest on the piston dome.......slowly rotate the engine. The TDC on the crank should align when the copper wire is at it's highest point and will fall back from it's peak as you rotate back and forth at the TDC mark. I like to dab some paint on the crank to make the mark easily spotted when doing any timing jobs. Compare to the first pic. Leave at TDC. NOTE: There are 2 TDC with a 4 stroke engine.......720 deg of rotation. The position of the cam at TDC will determined if it is OVERLAP or compression/IGNITION/power . This has caught many a person on V-Twin engines that will run BUT be low power and the wrong exhaust note. Both cams are "TDC" and fire OK but they are not "phased" correctly. Short and Loooong intervals between the front and rear cylinders power strokes.....gives a lumpy sound. Yours is a single cylinder. Your timing was correct or off by one tooth. Your pic is shot at an angle so hard to tell. When you are putting the new head and cam on, inspect the cam assy. Get a good look at the cam and the compression release "mini cam". Slide in the cam with the lobes AWAY from the rocker slipper pads. REF your pic above........The longest RED ARROW aligns with the cam mounting bolt(s) and the cam gear punch mark which is hidden when assembled. It is UNDER one of those stamped thin step folded metal "keeper" for the flyweights. When the flyweights sling out with engine RPM rotation, it will turn the smaller round disc by way of the dual connecting pins. The cam gear timing mark (dimple) is under the upper (in your pic) keeper close to the teeth. Right below this bolt is the timing mark for the compression release mini cam.....the quarter sized CENTER disc in your pic. It is just barely showing (about half of the dimple circle) adjacent to the RH side of your RED ARROW. This dimple should align with the cam gear dimple....NOTE: It can be put in 180 deg out relative to the valve cam. I always put a dab of white paint on the cam gear timing mark with a little smear almost up to the teeth (on the machined rim) so you can see the timing mark AFTER the keepers are installed under the cam mounting bolts. Timing alignment: (1) TDC mark on the flywheel at case mark WITH the slack taken out of the tensioner side of the cam chain (no tensioner installed yet) along with (2) cam gear paint mark AND and the dimple in the center disk (compression release mechanism). Install tensioner and "hand" crank (turn over) the crank to ckeck for binds. Special note to NOT adjust the valve clearance when the cam is on the compression release ball. Hand turn the crank to the TDC and at slow RPM (as in hand crank) the flyweights will be pulled in with the springs (the compression release is active and holding the exhaust valve slightly open with a small ball under the exhaust rocker.........will give the wrong valve adjustment. Continue turning in the direction of rotation until the ball clears the rocker (recess back into the hollow cam center). Finger tighten the adjustment screw to ZERO clearance and reverse the rotation. When the compression release ball starts to get under the cam, it will "lock up the flyweights". Manually rotate the flyweights to the extended rotation (RUN) position and your should be able to reverse the motor/cam even more. When close to TDC, adjust to spec clearance. The extra step above seems to be extra and not needed but what you are looking for is a bad batch of compression release cams....... the flyweights did not collapse to the fully closed position. I had these cam problems also in the Yam Rhino (identical weight tab welds and tooling cuts (same OEM???) and my modified cam (my personal shelf stock) given away to fix a Rhino. My modification was the grind the excess material on the welded on tab to give the rest of the clearance at where it rubbed the compression release "quarter sized " disc. Covered in an earlier BEN 1098 post.

you don't mention the outside air temp humidity dew points. Your Kohler engine model wants to ice up the throttle body in cold weather and even has an adjustable air intake scoop for cold air summer and heated (muffler) air winter. Thermal (temperature changes the operation characteristics) problems have the "delay" your describe. Old tractors and trucks/cars would have the outside carb body all frosted up with the correct cold wet snowy conditions. Look at the throttle body and see if you can find a FROSTY correlation to the problem. Try some straight gasoline (no Ethanol). Nothing runs good on that E85 in cold weather. We have had stations add water to the ethanol blended gas and then have the phase separation catch them with a slop unburnable bottom at the fuel pick up level. Runs fine, get a fill up and your are dead on road or barely keep it running.

above steps are right on BUT to make the job easier AND QUICKER...beat the book------------bleed the air from the overflow line (hose) to the puke jug. 1. Fill the puke jug above the cold line by about an inch with straight antifreeze......no mix.....with the hose connected between the puke jug and radiator neck 2. fill the radiator fill neck one last time to the top. Will try to drain back into the puke jug........normal 3. seal the tank lid along with an added air hose with a shop towel and blow air (lung power is just fine---you don't want a fountain for the neighborhood cats to lap up---- into the puke jug........forces the coolant up into the radiator filler neck. 4. When the bubbles stop and the concentrated antifreeze swirls into the filler neck.....maintain pressure and then install the radiator cap. no drain down of antifreeze. 5. release air pressure and remove the sealing shop rag and hose tubing....... install the puke tank lid. This saves the time wasted on having to heat cycle multiple times to purge the line to the puke jug. chow.

Don't know your machine BUT you described the broken off exhaust pipe tip "with the sensor still attached and connected". This have 4 wires and looks like an O2 sensor? If so, your ECM doesn't know the fuel air ratio (amount of O2 in the exhaust) with it reading open air O2 content and mapping to the wrong injection pulse width (amount of fuel). That said.....reattach the tip and seal good enough so that no free air (O2) enters downstream before the O2? sensor. Might want to undo the fuel pressure bump up and check again. Some of the different O2 sensor vendors for the HiSun variants had problems......e.g. 2 hole vs 3 hole and had erratic runability problems with everything else working AOK. Even had some new junkers right out of the bag.

First, you need to confirm that the fuel level in the carb is low and/or the gas has "cooked off" the good stuff and won't start on what dead fuel is left. Simple test: Fuel bleed down problem OR having to look at possible carb issues. Disconnect the fuel line at the carb and cap (you don't want a pumped fuel leak here if it fires off and starts running). Your machine "should" have the mini fuel tank that is mounted on the heat shield behind the seat. If the tank has indeed bled down, no fuel will run out. There is a post from "DOC" that had the hose diagram hook up connections. Buy or make a hanging test tank to now supply the good/new fuel to the the carb. Let bowl fill for say 10 sec. Crank over engine. If the engine fires right up, you have a drain down problem. Also, while running, check if the fuel pump is indeed pulsing fuel to the mini tank and has refilled it. From your description, it is working AFTER it gets running. Fuel will flow out when un-capped if it is working AOK. Catch can and rag use here for safety. FIX OPTIONS: BE SURE THERE IS NO WATER OR PHASE SEPARATED OH FUEL IN TANK BOTTOM. Cheapest (but not the best) is to buy a "foot valve" type intake fuel pick up "gumdrop" with a screen and install on the bottom of the in-tank pick up line. Check the NEW dip tube length because you DO NOT want the gum drop rubbing a hole in the bottom of the plastic fuel tank. Found a major mower OEM had this condition from the factory.....BAD. Your machine may have already been fitted with a fuel tank bottom dip tube intake filter.....they sometimes get choked off. The foot valve gumdrop pick up filter includes a spring loaded check valve ball to make it a one-way valve (check or foot using the water well plumbing term). Fuel cannot now bleed down back into the fuel tank with gravity.....only evaporate from the carb bowl. MY FAVORITE FIX: Electric fuel pump.....low pressure version NOT FI. WHY???? Many reasons!!!! 1. Ultimate fix for gas golf carts,...gas pedal to start cranking. Grasshopper (Kubota 3 banger w\ mechanical fuel pump---COST to replace OEM, and other machines with the cheaper pulse type fuel pump (run one dry and then you have to puff up the fuel tank and fuel lines to get fuel back up to the stock cheaper pulse pump again-----THEY DON'T PUMP AIR. Example...My neighbor was mowing and run out of gas on his mega buck GREEN mower.....even filling the fender fuel tank was not enough to prime...portable air tank/detach fuel line to pump/ to the rescue. 2. Switch off the electric fuel pump when finished mowing/riding and "run down" carb bowl fuel level to a "fast idle up"---lean mix---the carb bowl fuel now is almost empty. When used the next time, turn on the IGN and the added fuel pump switch.....wait for the pump hum/thump to change sound and by golly, the carb bowl is full of new fuel (not cooked off crap) and ready to run. 3. This dates me some, but 50's GM 6 banger/1 bbl Rochester had a flooding problem in the Spring time. Cold fuel in gas tank from overnight. Drive to town (couple miles). Load some feed. Come back out to go back home and the winter blended gas cooked off and expanded and overflowed into the intake manifold. Reason was the cold carb from fuel tank and it's normal damp cold icing problem....fuel now warms up because it is also sitting above the adjacent HOT exhaust manifold runners. You would have to lift off the carb and soak up the liquid gas with a rag inside the intake manifold. Drain the carb by dumping over and out the atmospheric vent. Reinstall and cap the fuel filter inlet and do a WOT and pray the plugs weren't TOO WET for your 6 Volt system.......Oh! the good old days. I have had "enclosed motor" mowers do the same thing by wetting down a less than clean burning plug. Not good when there is only one plug. AS for the mini fuel tank mounted behind the seat, it has problems supplying fuel to the carb IF you are climbing a steep bank or long hill. Not enough head pressure for the increased fuel demand for the hard pull. Electric fuel pump helps here also as the "over pressure" is vented back to the intake side and the mini tank is no longer required.

All Balls CV Boot Kit......sold by MOTOSPORTS on line. Need model and year for the correct boot kit. I don't know if the 6 finger spreader tool is still available. Seen some cone type spreaders also (manual). You also need a banding tool to tighten the 2 ribbon band on both ends of the boot. CONTACT 866-667-6288

Just by the looks, notice the clean and corrosion areas of the tube. Suggests that the bolt was used with a rubber bushing mount......like a shock of possibly a suspension rubber cushioned A-arm. My guess is there are more of them......look for their sisters under there. If any found, check their torque also so you don't find more down the road.

Buzzing sound is probably from the starter solenoid.....kicking in and out. It needs a full 12 Vdc on the coil connections to pull in and hold. Best guess....a bad connection close to the battery heavy cables. Places to check are the battery connections. The ground wire to engine/frame. The heavy battery cables could have a weak connection between the physical copper wires and the end connectors. Use a BULB style 12 V tester probe and stab these points to see where the 12 Vdc is good and then drops out with the start function. What is going on is the bad connection will support enough current for the solenoid at the initial Start sequence. The bad connection limits the current flow when the starter's current draw is greater and the solenoid coil voltage drops out. The example of a weak or discharged battery.......the dash light are OK and light. The headlights may or may NOT be full bright but when you try the starter....they all will cycle with the solenoid buzz.

Go to the front diff. 2 connectors......Key Off......pull both connectors......Key ON....light go out or stay on? Goes out, the front diff switch encoder is in 4WD position. Light stays on, chase a ground in the harness. You need to determine what selection position the front diff RACK slide gear selector in in.......You might possibly be in 4WD all the time. Problems seen were a corn stalk tearing the harness, trash in the switch encoder, busted nubbin o. the rack, Critter eating the wires (insulation). You just have to look see. Info is to help guide in the search for the reason. Raise ALL 4 wheels off the ground on jack stands. N for shift lever position/2WD for diff lock buttons/lever. Turn rear wheels one side at a time....turn together but nothing on the fronts. Repeat on the front wheels for the 2WD position.......fronts turn freely. 3 and 4WD positions.....each front will lock to rear AND with the 4WD locking the fronts together along with the rear. Go underneath Key ON but Motor not running and listen (at the front diff) for the little gear motor's short running time to change for the 2,3,4 selected. If the rack and pinion RACK NUBBIN is busted....it gets tricky to replace and resync the rack position and motor stopped positions. Remove the plastic gear changer housing and look at the rack that slides back and forth (L-Middle-R-) and selects 2,3,4WD functions. Slide the rack with a finger and have someone turn the front wheels to determine if working. Reassy......Easiest to "sorta center the rack position" in the diff. Actually, slightly off center is what you want but I forgot which side to move it about a tooth distance R or L to work the best. Diff oil and O-ring to seal on the housing nose normal care in reassy.

Work backwards from the TB air intake boot. Suspect the critters made a home in the air box or the air filter got wet. If you find an air restriction...great. IF not, you need to give more information as to the running conditions with the air intake reinstalled......running rich?, will it rev up with throttle?, lost the MAP sensor?, etc.

Hate to tell you the "excess loctite" you find is actually sealant. The new installed seal stops oil on the OD of the cupped spline coupler. The inside spline(s) ALSO needs to be sealed. Clean BOTH spline(s) surfaces of ALL crumbs and oil. Goop it up good.....as in using a wooden tooth pick to "wet" the splines. The washer needs a good bead also on BOTH sides and the shaft and cup spline area. Last, it is best to use a new nut as the nut is a "locking thread" that cuts away some of the output shaft threads (and some of the NUT threads). Be generous with the waterproof grease to lube the new cup spline and the driveshaft ball spline.