Greg Kilgore

How old is the machine. Got a pic of gauge? Did gauge work at one point in time? Maybe this could help.

May be easier to get 2 more rims and turf tires.

To keep from replacing spark plugs. Soak in regular gas overnight and a good stiff brush to clean off the carbon for the next use. Carbon buildup can come from rich gas/air mixture like you said. But can also be a leaking fuel injector, weak coil spark, or bad spark plug wire. You can get a spark tester or make one. On one end has a tip where you plug in the spark plug wire. The other end has alligator clip that clips to engine block. It has an adjustable pointer so the gap can be adjusted. That way you can tell how far of a gap the spark will jump. About $15 at auto parts. I use this all the time for outboards. To see how strong a spark is. Should have a good blue spark. Red or yellow spark means weak spark. And jump a 7/16 to 1/2 inch gap with ease. Reason for jumping such a large air gap. It takes more voltage to jump a gap under pressure. Like the pressure in the combustion chamber of the cylinder than in the open air. And since we are testing the gap in open air. The distance has to increase. If not then maybe the spark plug wire has too high resistance or the coil is giving a weak spark. And the coil should be covered under warranty. To check the fuel injector. Turn key on, wait for fuel pump to kick off. Then wait to see if it kicks back on. I don't think the fuel pump should kick on unless the fuel system is loosing pressure. It's a closed system and unless you see a fuel leak. It would have to be the injector leaking or pump. And if pump leaking off wouldn't cause excess fuel in combustion chamber causing carbon buildup on spark plug. Should be able to find an injector or coil on Amazon for $35ish. But injector should be covered under warranty also. I order replacement parts off Amazon and had my machine (Axis) fixed before the mobile tech contacted me. 2 weeks after I fixed it mobile tech called and told me he'd order parts. I'm still waiting on the replacement parts. Just want to have them incase the drive shaft goes out again. Hope this helps some to point you in the right direction to resolve you problem.

NewtoUTV, as Bryan g said above. He runs a service center and has had new machines come in with air filter installed backwards. If the air filter was installed backwards that may make the machine hard to start and use more fuel or give a rich fuel/air mix and cause carbon build-up on plug. Doesn't hurt to check. Maybe need to clean air filter.

Lou, read this. Notice the mileage and the tank wasn't completely full. Just enough to read full. Fuel icon is lit just to be lit i guess. If it is low it will flash.

By fuel mix are you referring to fuel:air mix OR are you mixing gas and 2-cycle oil and pouring into the tank? I'm not familiar with the Coleman UT400 but, I'm 99% sure the fuel should not be a gas:oil mix. Like a 2-cycle engine. 99% sure the engine is 4-cycle. Even though it's a single cylinder. If using straight gas and still getting a lot of carbon build-up. Try a different grade/brand of gas. Maybe some fuel cleaner. Around here we have 1 station that sells REC gas. It's 90 octane and doesn't have ethanol.

Aefron88, I am wondering the same thing. Since there is not a U-joint. The drive shaft goes straight from the engine to the rear differential. There is a 1" square tube cage/frame(?) built around the engine and differential. That shouldn't bend or flex. To take the drive shaft out. Either the engine has to be moved forward or the differential has to move back. I didn't find any loose or missing bolts on the engine side or the differential side. The way the splines on the drive shaft sit in the cups. They go in about 2" and bottom out. I should have measured the length of the old drive shaft and the new one I put in. To see if there was a difference. I still haven't received the drive shaft the mobile tech was supposed to have ordered. And he hasn't followed up when he said he would inquire about it being on back order. The one I installed from Amazon fit perfectly and I have the machine back operational. Just wanting the parts in the off chance it happens again. As I said I was going up a dirt/gravel road that a dozer had made wash board type depressions with its tracks. Was moving about 20MPH with me and the wife. I'm a good 280lb. Wife well let's just say petite husky 😂 and say there was 400 to 430 lbs in the cab. The frame shouldn't have flexed but may have and with the torque of trying to haul our big behinds up the hill of wash board tread tracks. May have flexed enough to cause the splines to slip. I still have the old parts. I may try to do some kind of hardness test. Could try to "X" the side of the frame to reinforce just incase the frame did flex. Would have to take to a weld shop to get that done. I've got a Flux wire mig welder, but no where near enough experience to weld something like that. I'd have to nut and bolt it together. But that would definitely cause a weak spots. Just like the number of licks it takes to get to the center of a tootsie pop. The world may never know. The reason the splines stripped the way they did.

Well on 12/15 or so, I received a package from HiSun. Got the seal and engine cup for the axle and the rear cup that the parking brake rotor attaches to. But not the axle itself. Sent the mobile tech a text message inquiring about missing parts. Reply was he would contact hisun to see it they were on back order. Nothing since. I'll keep ya posted when I receive all parts.

Found this service manual. on page 8-14 has this diagram of starting circuit. From the diagram. The key switch gets power from the fuse in the starter solenoid. Then key switch sends power thru a fuse to a brake switch. Thru a safety switch back to the starter solenoid. To engage the starter. So the key switch gets power thru the solenoid fuse. Main 12V+ goes to stud on relay. Then thru fuse. Then to wire going to keyswitch. When you replaced the solenoid. Make sure the main battery cable connected to the stud that provides power to the fuse. Hope this helps.

Sounds like there is a fuse going to the key switch that is blown. And by crossing the wires, you are back-feeding power to key switch and ignition system. Remove wire and remove power from ignition system and the machine shuts down. Check for an actual fuse box or loose wire somewhere.

So have to push it while in neutral THEN while it's rolling, slam it into gear. That is not good on the transmission. Even when the engine is running, the clutch should not be engaged until there is higher RPM. Then the engine spins the clutch, the paws on the clutch slings out and engages the clutch drum. The drum spins the primary sheave. Primary sheave spins the cvt belt. Cvt belt spins the secondary sheave. Secondary sheave is on a shaft attached to transmission. Now the clutch is a wet clutch. It uses a special engine oil for wet clutch motorcycle, ATVs and such. Is it possible it has the wrong oil? Possible air filter? Possible fuel filter? Since it doesn't happen all the time it will be hard to test. Maybe the next time it happens. Jack up the machine so wheels are off the ground. Start again and put in gear. See if it stalls again. I just don't know enough to help. Sorry.

Here is the post about the shift issue.

6 round trips of 400 feet in a day. That is a lot of strain on a small battery and 400 ft is not enough run time to charge the battery. When trying to start, did you try pressing the gas pedal. Had similar happen and had to give it some gas to start and keep running. Changed the fuel filter and it did help. Maybe a fuel injector issue. Read somewhere there was an issue with the 400ut shifter popping out maybe on this board. The guy gave the fix. Said could be diy or actual fix from Coleman. I'll look and see if I can find it again.

Also wanted to mention this. Putting the exhaust back together and back on. Cause to get it out, I had to disassembly all 3 pieces and remove sections at a time. When I reassembled and got the machine started. It was quieter than before. So for anyone that wants to try to make their machine a little more quiet. Try to tighten all nuts and bolts dealing with the exhaust. Don't use gorilla strength. Just snug a little. You don't want to break a stud or bolt or strip a nut/bolt. And a little penetrating fluid. Sprayed for a few days (each day) before the adjustments are made wouldn't hurt. And most important, don't blame me if something goes wrong.

It took about 3 days 2-3 hours per day. To get the machine back together. Did not adjust valve lashing. Didn't want to take tank out so I could make sure I had top dead center. Didn't want to stick anything into spark plug hole to determine TDC. So I just put the valve and blower covers back on. And did an oil change. Anyway got the machine completely put back together 12/1. Wife and I went for a few rides before I had to leave town for work. Now the good stuff. On 11/23, same day I took it apart, I replied to the one and only email from hisun support again. Sent them the pics and asked for replacement parts On 12/8 the mobile tech finally called. Asked for the year and size. I was kinda a smart as and told him he had the workorder from hisun. That should have had the year, model, and serial number on it. He said it was there but he wanted to verify so he could order parts for hisun to send me. (Meaning he could charge hisun for a service call that he "verified" the info. Don't know just guessing.) The tech said a new seal wasn't necessary unless old one was leaking. HA! But I asked that one be sent just in case I needed it. Tech added that the seal wasn't easy to put back in cause of the location. Told him I think I should be able to get it. Tech said OK he'd order parts (engine cup, drive shaft, spring, and seal) and have hisun send them to me. To put a coat of grease on splines when putting back together. I didn't tell the tech I already had the repairs completed and the machine back together. I have another set just in case this ever happens again. Now if I had waited for the tech to schedule an actual visit, take the machine apart, then order parts, then schedule revisit to assemble. It would probably be February or later before the machine would be back together. BUT I have to say this much. Hisun did find and schedule a mobile tech to resolve the issue. And his number was Indiana area code. At lease 4 hours to the Indiana state line. Maybe if I had requested that I do the work and the replacement parts during my initial email. I would have been down so long. So I'll take part of the blame for the machine being down as long as it was. But hind site is 20/20 as they say. I just want to know how the damage was done in the first place. The way everything fits together. The only way for the drive line to slip the way it did. Either the engine or the differential has to move. And all bolts holding both in were there and tight. Also there is no flex in the frame around that area. Just don't know how that damage could happen. The tech did say from looking at the pics I sent. Looked like a circle clip was missing from the messed up spline end of the driveshaft. I didn't take any pics of the new part before I stuck it in. But I still have the bad one. (I'm a packrat.) So I guess I could compare rhe old one with the new one that is on its way here. Thoughts? Comments?

May a moderator can make this a sticky or something. The fuel gauge seems to be misunderstood on these machines. All blocks of bars (red and white) represent the fuel level. When the tank is empty the red bar AND the fuel pump icon flash. In the pic below, the fuel gauge indicates a full tank. In this pic the fuel gauge reads about 1/2 a tank. Notice in the 1st pic there is one red bar AND 5 white bars = full tank of gas. In the 2nd pic there is 1 red bar and 3 white bars = about 1/2 tank of gas. The tank holds about 7 gallons. I put 60 miles that trip and used about 3 gallons or so. Your MPG may vary. Hope this helps the new owners and soon-to-be owners.

Remove spark plug. Ground the spark plug to the engine. Remove the electrical connection on fuel injector (so not spraying fuel into cylinder. Less of a fire risk.). Check for spark at spark plug gap. Let us know.

Cool glad you got it back operational.

Explain the process on checking the battery please. Not familiar with that machine but the owners manual should tell where spark plug is. The battery needs to have a charge of about 12.6 volts to be considered good. Less than 12.2 and it probably won't kick in the starter. The stator charging system is not the best. Can you hear fuel pump? Any codes on dash?

Thought you were still having trouble and was about to reply. Then got the post where you replied to aefron88. 😆 Glad you got it fixed.

Glad all worked out. Your turn around time with hisun has been better than mine. I got a reply 8 day after I sent request for mobile tech. Replied 1hr later to email asking for parts and I'd fix it myself. Haven't heard back. That was over a week ago. Found parts (hopefully they fit) on Amazon and are currently on their way. Dude, that sxs has 4x4, diff lock, and a winch. Bundle up, maybe take a tarp or clear plastic or buy cab enclosure and enjoy playing in the snow. Usually we get 2-3 good snows here in KY (on WV boarder) in my area. I hoping to have mine back together in a couple of weeks and enjoy the snow when it gets here. Thanks for the reply, hope you and yours had a good turkey day and best wishes for a merry Christmas and a happy hangover.

RickinMT, Any progress? I finally got around to taking mine apart. It looks like the same damage as yours. Did you gets parts from hisun?

Cool. Glad it's running. Mines down for now but it's 65 out and wife and I went for a 30ish minute ride on 4-wheeler. If it's warm out go for a ride if not warm, bundle up. Enjoy yourself. Glad it's running.

Still having trouble? Just saw the post. Are you getting spark?

Well it got warm today. I got boarded also. Took about 3 hours and this is what I found. Transmission side. Notice some of the splines laying there. And chunks missing at the bottom. Drive shaft transmission side. What did they make this out of pot metal, aluminum, and the axle says it for a 700. The cab I have on the machine says 700 also. And paperwork says 500. Think most parts are interchangeable. Still haven't heard back from Texas since I offered to fix the machine if they would send parts. But I went on Amazon and found this. Says it should be here Nov 30th or so. Staying out of town so much I racked up a lot of hotel points. Used points to buy Amazon gift cards. So basically it's free. Part numbers don't match BUT I can always return if it doesn't work. And at least I can see a faint light at the end. It was a PITA to get that far. 1 Take wiring loose for bed lights. 2.Remove bed. Take heat shield under bed off. 3. Take exhaust hangers loose. Disconnect all parts of the exhaust. Disconnect exhaust from engine also. 4. Take heat shield off that protects the rear diff. 5. Take e-brake off. 6. Take bolts that hold rear diff out and one rear diff mount. 7. Wiggle and jiggle and a few 4-letter words and finally got drive line out. 8. Still have to take the cup out of transmission. Will wait for new parts do there's no chance of contaminants getting in the trans. Will prob have to take the rotor for the e-brake off the boss but will wait and see. I also have 65ish hours on the machine. And the way the valves sit. Now would be a good time to adjust them also. Really can't start the machine since the manifold is now off the head. I'll keep everyone informed.