Alien10

A little pressure in the radiator after sitting a few days would seem to preclude a head gasket failure between the combustion chamber and the coolant jackets. Pressure would push coolant into the cylinder or if failed between oil and coolant, into the crank case. Also when running, a head gasket blown into the cooling system will certainly provide pressure into the cooling system and exiting at the open radiator fill. There is a tester that will analyze the coolant to see if combustion products are contaminating it. Not sure if you can borrow one of these from a local auto parts store or not. There used to be a radiator air pump that you'd use in place of the radiator cap. Pump up pressure in the cooling system and watch the pressure gauge to see if it holds or bleeds off. In your video, the bubbles are somewhat consistent in volume over the course of the video with the engine idling. What happens if you raise the RPMs while watching the coolant in the radiator? Do the bubbles increase in volume as you would expect if it is coming from a head gasket leak into the cooling system. This is more of a guess on what you've found so far, but maybe there is still a big air bubble somewhere in the cooling system that is slowly percolating up as the pump is pumping the coolant.

Couple of other thoughts... A head gasket can fail to the oil passages, to the coolant system, or to the outside air. Are you getting excessive crank case blow by? Is there any external compression leakage? Are you getting combustion gases in the coolant system? Cap off coolant system shouldn't be expelling gases or pressure. Has the coolant level dropped or increased? Does the coolant appear to be contaminated in any way? (Oily, brownish tinge etc.) Just a few things that came to mind. Good luck.

Compression test clarification question. Did you get 120lbs that then bled down to 105 in 15 minutes of sitting? Or did you do a second test 15 minutes later and only got 105lbs. Remember, rings and pistons are not complete seals, they all naturally leak. Max compression is only required to be present during the power stroke, and for a fraction of a second. If there's no coolant in the oil, what else has convinced you of a failed head gasket? You might consider additional testing before tearing into the engine.

Thanks for posting the solution, that is what really helps others on the forum!!

Ridge Runner, I have to confess I got it from a YT video posted by a Hisun dealer in PA who said to be sure to put the pressure on it every time until you hear/feel that faint click so it wouldn't pop out of low. Haven't had a pop out since doing that.

Gorj, Any chance you can share what brake line/switch you bought? I'm tired of trying to toss a 4x4 under a wheel on a slope while holding the brake pedal down to keep from rolling away.

If the N light remains lit when in gear, you need to adjust the cable. Seems like you are not getting enough on the shift toward forward gears. Sensor still thinks its in neutral.

Forget about keeping critters out, they will get into just about anything you erect for storage. Harbor Freight's canopies are where you need to go. By the time you fiddle around with tarps, pipes, and ways to secure the tarps, why not just get the canopy that has a roll up door and room for your machine, and other stuff too. 10x10 is $179 10x17 is $229. You probably spent somewhere around $8,000 to $9,000 for the UTV, buy something to keep the weather off of it.

My 550 is also difficult to shift but more often into reverse. I find that hard on the brake sometimes will let it move easier into reverse. These cable driven shifters are not exactly great that's for sure. Is the idle set too high? Might check that if it moves at all when you do get it into gear.

I think this silly little E brake system is the same on the Hisun (Coleman 550 in my case) ICE powered models. Same issue of zero E brake after a month. Your original description of how to adjust is just perfect. I'm going to give it a try since there is really nothing in even the tech manual about it. Thanks for posting it.

Still if you are getting the rough running and sputtering, look into the condition of the fuel injector. They are prone to problems. In any case good luck, hope that oil remains in good shape.

Ah yes I see. Good advice for OP too.

Me too, low is plenty of speed on the dirt road I live on and the higher revs lets the engine breath deeply without excessive RPM on those short trips. It also has plenty of power for the 35 degree, 200 foot long incline up to my barn loaded with cut logs. One other thing I do is keep hand pressure on the shifter as I press the gas to get that final "click" into low. Happens about 75% of the time and it is an almost imperceptible click, but it is there. I don't get any popping out of gear either. Thanks for the comment on your experience so far.

Do I understand from post #15 that the exhaust is dark? Hmmm. That along with sputtering and rough running might suggest a bad injector just dumping fuel into the cylinder instead of the fine spray it is supposed to provide. Hisun injectors are said to be of fairly poor quality with early failure rates. You can see how it functions by testing its spray pattern on a white paper towel. Stream is no good, but a fine mist is OK.

Of course, it has to be more complicated, its the Government.