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PICTURES - My UT400 Loves To Smoke...


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Sorry for the novel... :(

I'm new to the forum and new to the side-by-side world. This is my first post.  A bit of background about me.  My dad was a mechanic all his life and he taught me what I was willing to learn at the time.  In the mid 60's we had a marina on a small lake in Mid-Michigan area that also service many surrounding lakes.  I was the mechanic.  We sold Polaris, Johnson and Arctic Cat snowmobiles along with Johnon and Mercury outboards, boats and pontoon boats.  We also sold Bridgestone motorcycles very early on.  While going to college I raced on the Ski Doo Michigan Distributor's race team out of Clare MI.  That was the first year for the factory race sleds, the Blizzards!  Anything with a motor and or wheels, I'm all ears and eyes.  I retired as a design engineer for the an O.E.M. making plastic production equipment.  Also served a stint as a Chevy/Pontiac service manager back in the 70's and 80's.  Oh, I retired the end of '19.  We had moved from MI to MO for my work and after 20 years there and retiring, we moved back to Mid-Michigan.  Nuff said I believe. :) 

I just purchased a 2021 Coleman UT400 that has 320 hrs. and 1420 miles.

I have multiple questions/issues.

1.  The wet clutch appears to be toast.  It will rev up high and just barely move.  Got one ordered, complete kit.  Shouldn't be a big job.

2.  This UT400 has a bad smoking habit and it think it's bad for its health... :)  It not only smokes on startup but continues to smoke until it's shut off.  I brought it home in my 22' enclosed car trailer yesterday and by the time we shoved and drove it into the trailer, the smoke was SOOOOO BAD, that we could hardly see out the back of the trailer.  Valve seals usually stop smoking after it starts up and all the residual oil has been burnt up.  Rings on the other hand seem to smoke the entire time the motor is running.  I've read that some of the Hisun motors have had suspect oil rings.  If this thing is smoking that badly from rings, I have no idea what the bore is like until it comes apart.  For the money, I'd rather have a complete cylinder/piston replacement kit and just be done with it.  Also put in new valve seals at the same time. 

Thoughts?  I can't think of anything other than the two items mentioned above that could cause this.  It's not like in the old days with a PCV sticking and sucking oil up from the valve cover area and feeding it back into the intake to be burned.  I think that with the above swapping of parts, that "should" take care of my smoking motor...

Just how is the oil level checked, dip stick screwed in or just stuck in the hole without screwing it in?

I also cannot believe that in these days of engineering marvels, that a company, or many companies, would design a motor with a wet clutch using the same lubrication system as the motor.  Trans I can see, not much wear particles from the trans.  But with all the junk flying off the clutch shoes and then recirculating into the lubrication system, hopefully the filter will strain the big chunks out prior to being pressurized and forced back into the bearings and cylinder area.  Just doesn't make good engineering sense to me.

3.  I see no issues setting the toe-in, but these little guys do not, from what I can find, any way to adjust camber or caster in anyway.  I'm guessing some of the larger more expensive side-by-sides have the lower A arms with threaded ends at the frame to turn to adjust the camber/caster.  I may elect to take my lower control arms off and cut the ends off and weld in adjustment bungs and rod ends to replace the stock units.  Am I missing something on the available suspension adjustments or lack there of???  Right now the right front tire is really tipped in at the top compared to the left side, also has a large amount of toe-out.  The toe-out will not be an issue to correct.

4.  How do you change the clock from 24 hour to 12 hour?

I'm sure I'll have more questions as I get deeper into my new toy.

Also, it came with a 60" plow and I hope to use this to keep my quite large driveway clear this winter.  I do have the luxury to do multiple plows during a storm to keep the level of snow down a bit.  Yes, I know, I should have bought a larger rig, but with the issues this has, I got it at a very good price.

Thoughts and suggestions appreciated.

Thanks, Dan

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1. Yep they're known for this, the plow mentioned won't help with keeping the wet clutch plates alive.

2. I would check the compression and go from there. I haven't heard of a lot of ring failures. There are complete head assemblies as well as cylinders available for very reasonable prices.

The recomendation is to go high on the oil. Motorcycle doctor sells an extended dipstick and tube for all models except the 400. The claim is that Hisun changed the dipstick shorter somewhere along the way and more oil helps prolong wet clutch life.

2.5. Every wet clutch motorcycle/atv/sxs I'm aware of shares engine and transmission oil. Make sure you use MA2 wet clutch oil.

3. Toe is the only adjustment unless you want to do the old shade tree method of bending parts to adjust caster and camber. I doubt most power sports shops have alignment tools anyway.

4. Not sure off the top of my head. There are user & service manuals available in the "downloads" section. The user manuals describe the clock adjustments.


I think I covered most of your questions.

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Thanks aefron88 for the reply and information.

I just found that the oil is checked with the dip stick unthreaded and just dropped into the hole.  DO NOT THREAD IT IN TO CHECK THE OIL LEVEL.

These manuals are useful, but still lack in technical information.  Like your valve lash settings, they're not listed in the manual or service manual.

To swap out the cylinder/piston assembly, I'll have to drain the antifreeze/coolant.  I see from the service manual that there seems to be a protrusion on the driver's side of the lower radiator.  Is that the drain for the coolant?

Also on the oil changes, how does one flush the front oil cooler?  Pull a line and blow the oil back into the crankcase?  Any thoughts on that?  Since the wet clutch went south and that's what I'm replacing first before the cylinder assy and the valve seals, I do not want to leave any debris in the cooler from the burnt clutch pads.

Thanks again, Dan

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Yes sorry that's how you're supposed to check it. The point I was trying to make is people recommend you run the oil higher than the dipstick suggests. Checkout the documents on "Motorcycle Doctor" for more details.

Not sure on the coolant drain as I haven't found a need to drain mine yet. I would steer clear of radiator drain plugs in general, as every time I've used one on a car it never seems to seal back up right. Personally I would just pull the lower hose.

As far as the oil cooler, normally I wouldn't bother, but if the oil is all gunked up with friction material it's probably worth unhooking the hoses and blowing it back with low pressure compressed air.

Another random thought, you might check the valve lash, especially on the exhaust as it may be sitting partway open, and the way the cylinder is tilted that valve stem seems to have oil puddled on it when sitting. I wonder of that might help leak oil into the cylinder? Its also entirely possible you have a stuck ring due to carbon, maybe a dry & wet compression test to see where you're at.

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I did finally find the valve lash specs and if you average hi/low, it looks like .005" on the intake and .006" will work.  I think I remember seeing that you did something very similar to those specs.

My next issue is trying to get the clear covers off from the headlight area.  I took out the two inside screws, but cannot find any others.  I see tabs on the bottom, so the clear covers do locate with the tabs and are held in with screws, but I'm missing at least a couple.  Any guidance to where those might be?

I also did a compression test, 150'ish.  That's low to what the book says, somewhere around 185 would be normal it says.  The spark plug is oily, but still sparks and the motor runs, just LOTS of smoke.  I do have the new cylinder/piston kit ordered so I will fill you all in on what happens when I tear it down.

Thanks, Dan

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Found out that to remove the headlight clear covers, you have to remove the hood from the grill and headlight assembly.  Then you can reach the other two top mounted screws to remove the clear covers.

As much dirt that these see, you would think that they would have made the covers a bit more user friendly to remove to clean.  Do this a few times and I'm sure some of the plastic female screw holes will either strip out or crack.


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Very interesting thread. Aefron88 and others have been a lifesaver to me, 2015 MSU 800. Just a comment, NONE of the UTV manufacturers give a rats bottom about the owner or mechanic...none of them. Friend has arctic cats, royal pain to work on OR get the right parts. Another friend had a Honda side by side, nice machine but weak front end assembly and again....pain to work on. Whenever we went hunting in the swamp he left his home and used mine because he said if he got tangled in downfalls (3-4" trees) he had broken several tie rod ends!!!  So like I said, he left his Honda home, which cost half again more than mine and we used the junk, Chinese Massimo!!! LOL

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In addition to all of the above, I have an oil leak.  The guy I bought from was not a mechanic of any sorts, but did say it "smoked a little" and has a small oil leak.  Not sure about the original owner or the second owner, but I'm sure it was just a pass-thru to my seller.  He got an estimate of around $1800 to $2000 to do the wet clutch, but the mechanic was not real sure what was involved and bid high.  So pass it on to the next fool.... ME! :)

I got the Coleman up on my new 2-post car lift and was able to see where the oil leak was.  At some time, original owner I would suspect, had an issue with the front drive housing.  On the bottom of the housing just below the bolt-on housing with driveshaft seal, there was a big chuck of JB Weld and it was all wet around the stuff.  I got a small chisel and knocked it off, quite easily I might add.  There's a hole in the bottom of the case about the size of a dime slightly elongated.  It appears to be engine oil in that area.  Don't rightly know what it might have been to break the case, but it's highly unlikely that it was broken from the outside.  I also know that it's slightly lower in the case there than the drain plug.  I had the engine oil drained before I knocked off the JB Weld and there was quite a bit more oil that came out.  There's no drain holes on the crossmember.  When I cleaned the thing up with the pressure washer, water stayed on that BECAUSE of no drain holes.  I will add a couple 1" holes for easier cleaning later on.

So I'm thinking... that usually gets me into more trouble, but what if, the hole happened, ran low on oil, took out the wet clutch from running dry AND cause it to overheat and take out my piston/rings etc??? Wet clutch gone and the smoking engine may be related.  Any thoughts?

Also, anyone ever have one of these cases apart to know for sure what's inside in that area?

I'm sure I can do a better repair, even with JB Weld, than what was there.  I have access to the area with a long shank die grinder so I can rough it up around the hole and clean up the hole for better adhesion of the JB Weld.  Worse case, I pull the motor/trans combo and split the cases and TIG up the hole and inspect for other collateral damage inside.  I'm trying to get the history when or how the hole came about, 

Sorry for rambling on and one and on... 

Got the wet clutch parts yesterday and waiting for the cylinder/piston kit, probably tomorrow.

Have a great evening!  Dan

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No worries, not sure on the hole location. Got a picture? It's very possible a low oil situation can toast the wet clutch quickly, as can a wrong type of oil situation.

The manuals for these things have a mixed messaging on what viscosity and type of oil, but it should be MA2 rated due to the wet clutch just like any wet clutch vehicle. Modern conventional automotive oils have viscosity modifiers which can cause the clutch to slip and once it starts it goes downhill quickly. Being an automatic (CVT) it can be harder to noice a slipping wet clutch unlike on a motorcycle.

Sounds like you've got a big project ahead. Post lots of pics and what you find/do as it can always be helpful for the next guy.

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  • 2 weeks later...

Could have bet I posted this already from my iPhone, but sometimes it doesn't show up on the forum.

I have my Coleman UT400 up and running again with new wet clutch, new cylinder/piston assembly and the hole in the crankcase fixed.

Not sure how many pictures will be posted, but I've at least attached them to start with.

The hole in the crankcase early repair before I bought the UT400.  The hole after I just tapped the JB Weld off, literally just fell off the aluminum.  Don't have a picture of my repair, but it looked very good and should hold as I did grind the surface and had it super clean and free of any oil.

The wet clutch was my first repair to be done.  When I pulled the housing off, the over running sprag clutch just fell in pieces.  The round rollers are no long round. :) The clutch material was also worn out along with the drum.  The drum was grooved badly.  It all went back together nicely and no issues in that area for leaks.

I noticed when I started to tear down the motor that the intake valve had no lash at all.  The exhaust had around .020" lash, way too much.  I drained the radiator via the main feed hose under the front floorboard area.  This is the lowest point in the system.  I have very little antifreeze leak out when I pulled the head and cylinder.  I had to adjust the ring gaps on the new rings.  I noticed that the old piston/rings "seemed" to be a bit weaker in tension than the new rings.  Understandable based on the condition of the piston/cylinder.  The piston was scored badly on one side and a little on the other side.  The cylinder could be honed out and probably reused with a new piston and rings.  BUT... for under $130 I got a new cylinder, new piston and rings, new head and base gasket and piston pin with cir-clips.  I could not afford to do any less for that amount of money.  The install of the new cylinder and piston assemble went very well.  I did the valve lash, .006" intake and .007".

It started right up and was smoking quite badly still.  I would have guessed that based on the oil I used on the piston and cylinder upon re-assembly.  It took about three miles to eventually dry out the muffler of the residue oil from the bad piston prior.

I have no leaks and it runs and starts great.  It moves nicely too.

I'm speculating that the original issues were from the hole in the crankcase that led to low oil, wet clutch burn out and the dry cylinder/piston scoring.  So hopefully it was a one off, and not something I need to worry about again soon.

There's no noises in the driveline and it runs through the drive modes on the hoist without any hiccups.  The ONLY concern I have is what caused the hole in the crankcase???  I came very close to removing the motor and splitting the case, as long as I was that far into it.  I have a TIG here that I could weld the hole up for a TRUE fix, but I'll take the chance that whatever it was, is long gone for now.

If I missed anything and anyone has any questions, let me know!

Merry Christmas everyone... :)














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  • Dan_Lockwood changed the title to PICTURES - My UT400 Loves To Smoke...

Just a few more of the rig and the KFI snowplow.  It's a 60" blade.

I decided to get the KFI power angle kit for the blade.  That should be nice when the blade is all covered in snow. :)

I wired in the angle switch just to the left of the shift lever and wired in a dual throw momentary switch for the winch.  I wired the winch switch to the under-dash wiring in parallel so both will function as normal.  I didn't want to have to use the winch remote when plowing, PITA in my opinion.

That's it for the plow.  I may upgrade to an enclosure yet this winter, depends on the weather etc.

Thanks, Dan






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