K321 Smoking.....and not from the exhaust

[Wheelhorsedairyfarmer 13]

Just had the C-141 out mowing. Wide open, smoke coming off the front of the engine below the air filter. At an idle, no smoke. There's no oil on it that I can find, and couldn't smell any gas leaking. Any thoughts? 

[Trouty56 567]

Pull the head and check things out....I just helped my son in law....the cylinder wall is so scored he probably needs a shortblock.  You have blow by past the rings....

But I am not an expert.....

[Wheelhorsedairyfarmer 13]

So perhaps a rebuild is in order for me?

[JimmyJam 542]

Yeah... What causes an engine to smoke? Will a de-carbon fix it or does it require a rebuild?

 

So perhaps a rebuild is in order for me?

[Trouty56 567]

So perhaps a rebuild is in order for me?

Yes...in the engine I just looked at the compression was really low....we spun the engine backwards because of the acr....we only got <60.  Opened it up and there was really bad gouges from the wrist pin allowing blowby into the crankcase,  The crankcase vent was blowing this mixture out the area you described....

[Fordiesel69 271]

Is the engine still powerful?  Does the engine burn oil during the season requiring top offs?

 

A glazed cylinder, in conjunction with worn rings can cause this and the engine may still provide 10 more years of service.

 

Carbon will not cause this.  If it is, the rings are already damaged. 

[JamesBe1 84]

I'm glad I stumbled on this thread.  I've seen this before and wasn't sure of the cause.  Now I know.

 

Bob - how do you manage to spin the engine backwards?  Can you spin it fast enough by hand or does it not make any difference how slow you are able to turn it?

[MarkPalmer 81]

Spinning the engine backwards will not work to check compression.  Only getting it above the RPM which the ACR releases can be used for a compression test, which is not easy to do.  A cylinder leakdown test is the best way to check these engines, a gauge is about $35 at Harbor Freight.  As mentioned the smoke is coming from the breather outlet, it is cylinder blowby gasses.  Probably time to have a look at the condition of the rings and cylinder.

 

 

-Mark-

[Trouty56 567]

I'm glad I stumbled on this thread.  I've seen this before and wasn't sure of the cause.  Now I know.

 

Bob - how do you manage to spin the engine backwards?  Can you spin it fast enough by hand or does it not make any difference how slow you are able to turn it?

 

Put two Wheelhorses nose to nose James.....use a belt from pto to pto....

 

 

Spinning the engine backwards will not work to check compression.  Only getting it above the RPM which the ACR releases can be used for a compression test, which is not easy to do.  A cylinder leakdown test is the best way to check these engines, a gauge is about $35 at Harbor Freight.  As mentioned the smoke is coming from the breather outlet, it is cylinder blowby gasses.  Probably time to have a look at the condition of the rings and cylinder.

 

 

-Mark-

 

I thought I read this before Mark....I'm sure I did....but I am a little gullible at times.....

[Wheelhorsedairyfarmer 13]

Still has plenty of power, was mowing stuff taller than the hood when it was doing this, but this wasn't the first time it smoked from by the air filter, just the first time I saw it in daylight. I saw it in the dark in my headlights last week, but I figured it was steam off the damp grass or dust even. But I had the head off to change the head gasket, cylinder looked to be free of any scores or scratches. And a couple weeks ago I checked the oil and topped it off with a quart. Changed oil back in April right after I bought it. So April to June went thru a quart. One of the fellas on chat last night suggested using Risoline.....however I've got a big bottle of Lucas oil treatment in the garage, says it "slows blow by". Safe to use in a single cylinder Kohler? I use it in my truck pretty regularly and keeps it running strong. 

[WH nut 553]

If you put a QT IN it you have already caused some damage. The thing only hold a tab more than a QT.

[MarkPalmer 81]

Sounds like it's using a ton of oil.  Was there a lot of carbon and oil on the top end when you had the head off of it? 

 

-Mark-

[Fordiesel69 271]

Agreed.  I you added 1 qt, the engine is in need of a tear down before it blows.  I beleive the distance between F and ADD is 1/2 qt on one of mine.  Its been so long since I had an oil burner I can't remember.

 

Rebuild kits are super cheap on ebay, and seem to work well.  The factory one peice oil ring is a real dud even after a few hundred hours.  The aftermaret kits and any genuine kohler ring set will contain a 3 peice oil ring which is FAR superior.  Harbor frieght will have a cheap cylinder hone to help you get it done properly without the added cost of a machine shop. 

 

I use plastic guage to check rod to crankpin clearance.  I do not trust measuring it by hand using telescoping guages & mic's. 

[DON 0]

If the top end of the mtr is clean you may have a carb float issue allowing fuel to leak down to crank case dilluting the oil causing it to wash down cylinder and blow by rapidly? just a thought....GOOD LUCK!

Don

[Wheelhorsedairyfarmer 13]

Sounds like it's using a ton of oil.  Was there a lot of carbon and oil on the top end when you had the head off of it? 

 

-Mark-

Head was covered in carbon, soaked it in carb cleaner overnight and was able to get it pretty clean. Estimate of time to burn a quart through it was about 100 hours. Carb could be an issue too. Never rebuilt a motor myself before, so I might chicken out and call the dealer for a guesstimate of a rebuild or some other small engine shops. 

[Fordiesel69 271]

Oil interval is 25 hrs on these.  You cannot extend this even with synthetic as there is no filtration.  Its not the 100hrs that is scary, as one time is not going to blow the engine, its the 1 qt low that is the issue.

[Wheelhorsedairyfarmer 13]

Yeah, I get the oil usage blowing the motor. That's why I've started checking it when I start, and when I finish. Can't exactly see changing oil every other week. 310-8 got oil changed once a year all it's life, over 3000 hours on it and its not the worst for its age. This is why I hate being the second owner of ANYTHING! After I get the 310-8 put back together, 141 gets parked pending its evaluation. Might take the K341 off the Charger 12 and put it on the 141. Dunno yet. 

[Wheelhorsedairyfarmer 13]

Ok, another dumb rookie question.....can you get a k321 bored out to be a k341? With adding the bigger piston and other inside guts. Just wondering. 

[diesel cowboy 263]

Ok, another dumb rookie question.....can you get a k321 bored out to be a k341? With adding the bigger piston and other inside guts. Just wondering. 

In short no.  I mesured on one of mine because I wanted to do the same thing.  The ones I had I took the spec's for the 341 std. size piston and managed to measure the outside of the block on the 321 in the bottom of the fins and it would have left about .030-.040 of material on the cylinder walls and that would have burned out quick if it did'nt just blow through as soon as it started.      Stewart