Mule 610 smoking

[Bufit]

A few months ago I pulled the Mule out for a ride around the neighborhood and while pulling a hill it was blowing white smoke out the exhaust, kinda smelled like burning oil. Came home and checked oil level, looked for leaks and all appeared good. Today I took it out to the hunting camp and she ran like a champ until lunch. There is a steep hill that I have to go up to get back to the truck for lunch. Pulled it fine but when I looked back it looked like I was a bug truck. Again, full throttle, under a good load, empty bed and 2 passengers. I ran it hard last year at the same hill with no problem. I have not run it since last Jan, so she sat up in the garage from then until July or so. I figured gunk in the card the first time but again today has me concerned. Any ideas before I take it in?

[unit5alive]

When I picked my mule up at the dealer, after they assembled it , it seemed to smoke a white type of smoke ,they said that was normal ,checked the oil looked fine. when I got home with it I pulled out the plug on the bottom of the muffler and got almost a cup of water out of it !, the mule was a left over 07, I just bought in august, in the sealed crate , how could it have that much water in it?, condensation ?,after I drained the muffler ,it stopped smoking , or steaming

[RCW]

Pull the small vapor line from the top of the air horn that runs to your carburetor, I suspect it is very wet from oil and combustion condensation.

It that is the case, you need to run a bit of SeaFoam through the gasoline, run it for a couple of hours, and let it work the rings loose. Then change your engine oil.

What happens is the rings take a bit of as set, some techs refer to this as relaxing, when they set for long periods. This causes them to bind to the piston and not seal as well as they should, and then you get excessive blow-by until they reseat. The cylinder walls also get a slight surface rust that the relaxed rings will not readily scrape off, so your have to run it long enough with the rings free to repolish the cylinder walls.

The solution is to start and allow the Mule to warm up every few weeks, and to not let it set for extended periods. I add a very small amount of Stihl chainsaw oil to my gasoline engines, then start and warm them up before storage. That oil works as a top lube and keep the rings free and the cylinder walls from rusting.

I also change my engine oil before winter shut-down. That gets rid of the water that has accumulated in the old oil from normal combustion.

[Bufit]

Ok, so I put some Seafoam in the tank and ran at idle for about an hour yesterday. Tonight I got home and took her for a ride and she did better. Ran her hard the whole time-uphills, downhills and level ground. She is still smoking pretty bad and you can feel a power loss just before you see the smoke. Probably smoked four or five times. I am supposed to go plant green fields this weekend and I use it for spreading and covering all the fields. I am concerned that the smoke thing is not good and am afraid she make self destruct on me. Any other options? I was going to go get a new oil filter tomorrow and change the oil, while there ask the tech what may be the reason or would I be better off taking it in and having them go over it? This is the first time since I bought it that I have had a problem and the first time it has sat for longer than a month.

[RCW]

The power loss concerns me.

Was there a great deal of liquid oil or a greasy white foam in the line from the top of the engine to the carburetor intake? Is the air box full of oil and do you have a saturated air filter?

If so, do a compression check, and pull an oil sample from the oil you are going to change, and have it tested. Caterpillar and Amsoil dealers are a very good source of oil sampling services, and they all will take the time to explain what it means afterward.

If it has excessive blow-by and that line is drenched with oil or a water oil mixture I would not use it until after the oil sample is back. You could be looking at a blown head gasket or a mechanical issue that will require further testing such as an oil pressure test and compression test.

If the small line from the engine to the carburetor tube is clean and reasonably dry, just a little dampness, then I would pull the bowl off the carburetor and clean the float needle valve. You may be getting crud stuck in that valve and flooding the engine. That will drop the power, create tons of white smoke, and the exhaust will usually smell quite strongly of unburned gasoline.

If a rod bearing fails they will exhibit a noticeable change in exhaust tone, seem like they are losing power, and start burning oil in major clouds. That is a worst case scenario, and highly unlikely. You normally will hear a distinct engine knock, like a woodpecker whacking, if a rod is failing. The spark plug will also be excessively oily in most cases of rod bearing failure. But, if it is not the carburetor flooding or oil from blow-by, that is the next thing I would check unless the oil sample comes back with anti-freeze in the oil. The oil sample with the old used oil will tell you in a heartbeat if there is any serious worry, so it is money well spent.

[Bufit]

There is nothing in the air filter except dust. Where is the line thingy going to the carb, actually where is the carb? There would not be any coolant in the oil b/c its a 610 and its air cooled. Power is ok most of the time, it just goes down just before the smoke appears. It appears for about 5 seconds then goes away and power is back and up to full speed.

[Bufit]

Well, I took her in today to mother kaw. The tech took it for a test ride and it actually did what I was describing, that's a first. They seem to think it is the drive belt but will not know until they can dig into it which will be awhile. Apparently the Ethanol is doing some bad things to Atv's, there we 90 in there for carb issues and annual tune ups before bow season next month. They think it will be 3 to 4 weeks before I get it back, we'll see. I called two other shops I trust and one was 3 weeks before I could even get in and my favorite shop doesn't work on UTV's any longer due to the owners bad back. Thanks for everyone's input.

[Dave Slauson]

Hi
I am a newcomer and leaning toward the Mule 610. I used to hate ALL of these ATV's when I was in the back country with my horses and one would zoom in beyond the "no motorized vehicles" signs. Now I have had 2 back surgeries, am done with the horses, and the Mule 610 looks about right for me.
I do not intend to stray overland too much, mostly established trails, am no mechanic, and require reliability. Suggestions? Thanks Dave Slauson

[DocLewis]

Dave, I just bought a brand-new Mule 610 4x4 camo and am very pleased with its performance. I drove a Suzuki LT250 QuadRunner 2wd for 16.5 years and since I'm getting older, I really wanted something a little more stable (wider stance) and easier to get on (low, open floor boards) and easier to steer (traditional steering wheel). It does not do well with engine compression braking, but the foot brake seems to be OK (not great, but the hand brake is superb). Cargo capacity is wonderful compared to what I had on the Suzuki ATV. Doc

[DrPeeb]

My Mule 610 camo is pretty much perfect for me. Runs great! Great on gas! Plenty of power; 25 mph is plenty fast for me. Turns out you can JUMP IT at 25 mph! Also turns out that with it in 4WD you can go up some VERY STEEP TERRAIN even with TOO MANY PEOPLE ON BOARD! Brakes aren't great (foot brake anyway), but I can yank up on the hand parking brake and lock 'em up, even on pavement! Battery is pretty weak, since I mounted a stereo in mine, but I'm going to put in a larger battery. Headlights are GREAT, brighter than my Titan's! I love the camo: I'm kind of a nitpicky dude, and with the camo it never shows any dirt that bothers me; Actually it looks like it SHOULD be dirty!

[DocLewis]

I've been very happy with mine! I went from a Suzuki Quadrunner 250 2wd for the past 16.5 years to the Mule 610 and find several differences: lack of engine braking, even in low range; brakes somewhat lacking. But, I love the camo, the 4wd and locking diff, the roll cage, the bench seat, the large cargo bed w/tilt. It is much wider than my Suzuki so some of my deer hunting trails have had to be widened, but my Kubota tractor makes it through many of them with the bush hog, so I'm pretty good there on width.
I've got a 3,500# winch ordered, a camo soft top, a camo seat cover, and a 2" receiver hitch -- these all should arrive today or tomorrow so I'll be really busy this weekend! Doc