Prepper

I have been doing a little research on which engine oil is best for UTV engines. There seems to be some disagreement over using a good quality regular engine oil, and the necessity of using "M2" (or wet clutch suitable) oil. My understanding is the "wet clutch" suitable oil has less friction reduction properties (hence a more responsive clutch with less slippage). While less friction reduction properties would seem to be better for the wet clutch... it would not be best for the internal engine parts like camshaft bearings and other moving parts where friction is detrimental and would lead to premature failure. Some folks swear you need M2 oil, while others say they have been using regular motor oil for years and their clutch is just fine. Could they both be right ??? Any thoughts ?

Well, it appears all it needed was some time. After several attempts, it started to idle just fine. After reassuring myself that it appeared to be running well, I took it out on the road for some "run" time. It was sluggish to get rolling (like the belt wasn't gripping) but after a few miles it got much better. I think it had been sitting for quite a while and things just needed to break in a little. After several miles both the engine and drive train seems to function normally (at least what I would expect). The only thing that concerns me at this point is the high-end engine RPM. Does anyone know what kind of max- RPM's I could/should expect from the engine? Right now it seems to start bogging down in the over 4k range (sometimes it will get to 4200). Not sure where the ECM starts clipping the RPM's at. The ECM I purchased at Motorcycle Doctor was the "enhanced tune" unit that is supposed to allow for another 500-RPM's. Is 4k all I can expect from the engine ? Additionally, occasionally, the engine hesitates a little from a complete stop, but quickly picks up and takes off. That may work itself out with some more miles on it. But all in all... things are looking promising at this point. It appears the ECM (the WRONG ECM) was the main issue from the beginning. I suspect when the original owner bought the new ECM, and that didn't work to get the engine running again... he threw his hands up and quit. Little did he know that either he ordered the wrong ECM, or, the company simply pulled and shipped the wrong one.

UPDATE: Got the new ECU today. Installed it and the engine fired right up ! Success... but it will only idle for about 30-45 seconds, then dies like someone cut the power. Cycle the key and it fires right back up, and I'm talking immediately. Runs another 30-45 seconds, then dies again. Plenty of fuel pressure, will test again tomorrow to get actual numbers. Right now I'm thinking Idle Air Control. I'll remove that tomorrow and check it out. I have no idea how long the machine has been sitting without running. Good news is though, the engine sounds strong when it is running. I'll report back on any progress.

Ben... I have attached a picture of the ECM. It's a MT05, but I am confused if my MT05 is the correct one for my single piston engine, or the ECU for a single piston engine is a completely different part number. If the MT05 is NOT the correct part number for my engine... then this whole situation of crank but no start makes sense. From what I understand about the history of the machine, it quit, and in spite of throwing parts at it (including a new ECM), it never started again. As I understand it, it appeared the fuel pump stopped working so they replaced it with a new one. When that didn't cure the problem they eventually arrived at taking a look inside the fuse/relay box to see if any fuses or relays were broken. They damaged the box trying to get it open, and called it quits, and sold it to the guy I bought it off of. He ordered the relay/fuse box but sold it to me before the part arrived. He gave me the part after it arrived but of course that didn't cure the no start issue. When I got it the issue seemed to suggest a timing issue so I checked the valve lash clearances. It was then that I saw the lobe for the exhaust lobe was about half worn off. I figured that by the time I paid for a new cam, rockers, and valves, etc. I could just buy a complete head assembly for a few bucks more. I didn't think the cam was wore off enough to keep the engine from starting, but it was worn enough that it needed to be replaced, and now would be a good time rather than later. Regarding the question about prior techs swapping pins, I think there is less than a 1% chance of that having happened. I will call Motorcycle Doctor tomorrow morning and see what ECM I should have. I bought the head from them, and also a seat assembly so they have had some business from me recently. Thanks...

Ben... pro tip on the video... when the video is playing, if you tap anywhere in the video screen options will appear. Tap on the Gear icon and you will see a list of options. Tap the playback speed option and select .25. It was easier for me to focus on the flash of the 180 degree flash in order to determine where the TDC flash was firing. It's obvious that it's several teeth off. However, I am certain I have the [single] line on the flywheel in the window when I set the cam dimple to align with the TDC casting mark on the head. So either the mark on the cam was placed incorrectly, or the flywheel mark was stamped I correctly. However, right as the video starts (you noticed the compression relief was not working) it seems evident that the cam/crank timing is correct because of the (I'll call it the "stall") of the movement indicates maximum compression. At that point the flash illuminates and the position of the cam aligns with the casting mark on the head. (I'll follow up more later)

Ben... my flywheel on has 3 lines on it. There are 2 lines close together, then about 1/2 inch from those 2 lines, is a single line. My understanding is that the single line is the TDC line, and that's the line that coincides with the timing line on the cylinder. Not sure what the other two lines are for, but they are real close to the TDC line. Here are the two videos that I uploaded to YouTube. General attempt to start video: https://youtu.be/YEwjWCKSS50?si=riBTrp53Qgs3UsP2 Cam timing video (also can hear the detonations in the background): https://youtu.be/V7tLV8F6G-Q?si=ZDRqVftru5Q9go-w Let me know if you can view them.

Opps... here is the video. TimingLightVideo.mp4

UPDATE: So... this is interesting. This is the results of the "timing" test Ben suggested. I uploaded 1 video, and 2 pictures. The video is of the cam/timing spinning while cranking (attempting to start. Plug is in, and the timing light flashes indicate spark. Seems like too many flashes to me. Not sure what would cause this, but maybe I should only be concerned with the one flash, at the right time, that makes it run. I don't know. The two pictures marked "A" and "B" are stills from the video because its hard to see the cam timing marks in the video while cranking. Picture "A" is the flash/spark at TDC. (RED arrow is the CAM timing mark, and the YELLOW arrow is the timing mark on the head). As you can see... its not flashing/sparking on TDC. That's a problem I'm not sure how to fix other than moving the cam clockwise about 3-4 teeth. In picture "B" (same color combo as "A") this is the flash/spark at 180-degrees form the TDC flash. Again, not where it should be. However, it appears this would explain why it won't start, yet detonation can be heard out the tailpipe. Apparently it's firing late. Does anyone know if there are negative ramifications of changing the cam orientation 3-4 (or maybe more) teeth ? Will that cause a valve to impact the piston ? OR... is it possible (safer) to change the timing of the spark? How would I do that ? This is just weird, and I can't think of anything that would cause this other than an misplaced TDC dimple on the cam from the factory. But the dimple lines up with the cam bolts, so I would think not. I'm stumped !

Ben, thank you. Back to basics is an excellent idea. I will get as much of those suggestions done today as possible. Question... we're you able to view the latest video of what the engine is doing during an attempted start? At one point you said you were unable to view on your computer. Can your computer view YouTube videos? IF so, I can put that video on YouTube and provide you a link for it. There are other ways to get you the video also, like Quick Share, Dropbox, etc. Maybe even snail mail via USB stick. Let me know. I think it would be beneficial for you to see the video. Thanks again...

Hello All... Still struggling with this 2015 MSU-500 crank, but no start condition. For those of you who may not have been following, here is a recap. Purchased cranking but not running. 775 miles and 127 hours on the display. Previous owner replaced the ECU, Breaker/Fuse box, Fuel pump, Coil and wire, new plug. I replaced Complete new head assembly (i.e cam, valves, rockers, etc), Fuel Injector, O2 sensor, MAF sensor, Stator/Pickup Coil, air box to throttle body boot. Engine has good spark, and fuel pulsing out the injector, and well defined timing marks on both the cam and flywheel. Valves adjusted to .004 intake, and .006 exhaust at TDC (as verified by both the flywheel mark, and piston movement). Compression tested again today @160psi. Starting fluid on crank makes no change. I have attached 1 video of what it sounds like when attempting to start it, and 2 pictures of where the cam timing is at. The two pictures were taken with the flywheel timing mark in the inspection window. Keep in mind that the pictures of the cam assembly are at a slight angle as it is hard to take a full frontal shot given the frame/head proximity, but from the drivers-side perspective using a mirror, the cam timing is dead on. The timing mark on the decompression cam appears to be in the proper position (pointing at the top casting mark on the head). Also, per Ben's posts (Thank you Ben) the cam decompression weights are free, and snap back to the position you see them in the attached pictures. The gap between the pin and the v-seat are the same as the old head. Today as a test, I adjusted the exhaust valve lash to .012 just to test if the decompression ball was holding open the exhaust valve slightly... this made no change and I have since adjusted it back to .006. I think I have run out of ideas. Any thoughts ??? Crank_NoStart_2.mp4

Thanks Ben... Can you help me understand the decompression function a little better... what I am struggling to understand is, if the decompression function is causing the exhaust valve to remain open slightly, ( during the "cranking" phase), then why is it I can have 145psi of compression when testing such. Seems to me that I should have far less compression if the decompression function was malfunctioning. I will pull the old weights to check for wear patterns, and attempt to make the same patterns (if any) in the new weights. Hopefully I can get to that tomorrow. I'll keep you informed as to my progress.

Thanks Ben... i do have the old weights, i will check them against the new ones. Have this improper fit situation been fixed ? The reason I ask is because I just bought the new complete cylinder head, cam included, and bought a new cam gear, with weights included. Thanks...

Hello Everyone... Still in a no-start condition. After replacing the stator/pickup coil, spark looks much better (stronger and more uniform). I can now here some detonation in occasional cranks, to the point of exhaust flange getting warm to the touch. I have attached some pictures of the current cam position. I have verified TDC by both piston travel, and TDC timing line on the flywheel in the timing window. In this cam position I have valve lash (.004 intake and .006 exhaust). I have verified fuel spraying out the injector. Compression still at 145psi. Anyone have any thoughts on if the cam timing looks correct? Keep in mind of the difficult angle to get a full frontal shot. Thanks...

Thanks Ben... When rolling the extension on the inside of the flywheel, I can feel the pull/push sensation you speak of. It's the same for ALL areas of the inside surface, so I assume the inner magnets are working correctly to generate a power sufficient to charge the battery (although I am more concerned with getting the thing running at this point). When placing a flat-head screw driver tip on the outer magnets I can feel some stickiness, but only slight and not as strong as the inside. I also placed the screw driver on the pickup coil and that has stickiness also. I tested the ohms reading across the two wires coming from the pickup coil and that registered 232.2. I was unable to find the correct specs reading anywhere on that, but it doesn't really make a difference because I have a new stator arriving tomorrow. I will check the new one and compare the two. At this point I am struggling to find something that would explain the erratic spark display that can be seen in my spark video above. I don't think what is being exhibited in that video is correct. My thoughts are that maybe the plug is firing on the power side of the compression stroke, and/or maybe firing on the exhaust stroke to cause the popping out the exhaust. It's obviously getting fuel or there could be no popping out the exhaust. I truly believe the valve timing and lash is as close to perfect as a human can get it. However, if the new stator/pickup coil combo doesn't cure the issue than I'm at a loss for an explanation of the erratic spark. The ECU is new, the coil is new, and the plug and wire are new, and the connectors to the ECU all look good. I guess the new ECU could be faulty, but so could the next one I buy also, so I am not inclined to purchase a new ECU at this point (as it is making spark to the plug). If the new stator combo doesn't cure the no-start issue, then I think the only next step to try is to purposely move the cam timing on or two teeth each way and see if that makes any difference. I appreciate your replies !

I hate to replace the flywheel if there is noting wrong with it. Would you, or anyone, have a picture of that magnet (if there is one supposed to be there) ? I checked the pictures online on the sales sites and none of them show that section of the flywheel. I would like to verify if indeed mine threw a magnet or not.