I had the head off last month, thinking I had a blown head gasket. Mach shop said head in perfect shape, not warped, no evidence of ever overheating. He refaced valves , magnafluxed, etc. I replaced head gasket. cyl walls smooth as a babys butt, no ridge at all at top and pistons looked great, according to my BIL mechanic. replaced all valve seals, buttoned it up, and still smokes and uses oil.(1 qt for 13 hrs work) runs good, but I hate the smoke and oily mess coming from exhaust pipe. Prev owner had not changed oil in sev years, it appeared!! or filter! I inherited a tractor that had been abused, but that is another story. thanks to any advice from all you guys. I am no mechanic but have access to BIL mech, I think.
YM 2200 Eng Rebuild
- Thread starter jimsxl
- Start date
- Views: 13166
tmar04,You don't have to replace anything unless it's worn beyond specs,and you can't SEE this wear.Don't just start replacing parts,at a true 1250 hrs. your engine should not need anything ,except a valve adjustment.If the head, valves,and guides check out, and it's still using oil,then the problem is in the rings/cyls.--ONLY--a machine shop can pinpoint this.Perhaps your true hrs. are much more than your than your meter can log.Those guy's are out there! Jim
MJPetersen
Veteran Member
RIngs and cylinders that are worn enough to cause bad smoking would show up in a compression test. If you think that your rings are bad do a test of compression. You do not want to do things that are unnecessary and costly.
You want to find the true source of the problem before launching into an expensive repair.
Mike
You want to find the true source of the problem before launching into an expensive repair.
Mike
RobJ
Elite Member
MJPetersen said:
Not saying a compression test would not be in order...but...
Actually not totally the case. Tmar04 just added the secret comment. Dirty oil, not changed in a while, etc. Since the top of the cylinder has no ridge, we might be able to say the air comming in was not dirty. This of course doesn't mean the filter was not changed when it should, but if you are working in non dusty conditions, it won't suffer as bad as dusty conditions. Case and point my boat does not have an air filter, it's not very dusty on the lake or river.
But dirty oil will wear the oil ring quicker than the top rings. So yo ucan get oil bypass but still have good compression. If the oil rings wear bad enough then could break. But with dirty oil and a worn oil rings you have to look closer at the piston skirt and the lower cylinder.
If it was mine I'd still probably just hone the cylinders real good and replace the rings. Give everything else a triple check just to make sure too.
Here is a shot of my Kubota when I pulled the heat. I found a lot more wear than expected. Wear on top and I am getting some blowby. But the engine runs/starts fine and doesn't use a lick of oil. So I believe my problem is dirty air in the top end. And since I can still see factory cross hatching at the bottom, I have to guess the previous owner was changing the oil at goot times. It's all sort of a guess but I'm looking at what I have in front of me.
Rob
Attachments
Robj, and Mike in Poland, thanks so much to both. I probably will bite the bullet and buy Hoye's compression tester adapter and check compression, then make decision. Just wonder if engine (rings, etc) could be stuck, sludge etc from lack of maintenance from prev owner. I changed oil, put in Mobil 1 syn, and now will run it a while and make sure oil usage is the same. I am just trying anything easy, first, before tearing into it again. remember, starts good even in cold, 35 deg weather, without even using thermostart, smokes mostly upon acceleration, then clears up somewhat in matter of 2-3 seconds. but have nasty, oily residue , probably unburned fuel and oil, in the exh pipe. will advise more.
rock2610D
Silver Member
I know you have had the head off but what you are describing is valve stem seal leaks. Oil draining from top of head past valves an into cylinders. THis will cause what you are describing--- plus top side oil will help seal rings and such.
Gizmo36
Platinum Member
A two or three cylinder if run at low rpm all the time at low temp .Will make the rings stick. Get the temp up put a sub-soiler on it run it for two three hours under a load you want it to be pulling hard .That will un stick the rings.
MJPetersen
Veteran Member
I am inclined to agree with Gizmo that the thing needs work at a good working temp and it will feel better. Nothing like a bit of good hard work to limber things up--works for us humans too.
If I remember right you were complaining of this before. Did you get a chance to work it hard and did it help?
If you have good compression--there does not seem to me to be any reason to tear it down.
Mike
If I remember right you were complaining of this before. Did you get a chance to work it hard and did it help?
If you have good compression--there does not seem to me to be any reason to tear it down.
Mike
Mike, the problem seemed to be less after replacing the valve stem seals, and running it for an hour or so in my garden. then weather got bad again and can't use tractor in garden and too early to mow, so I will just wait a week or two then put it to the test again with harrow in garden area. thanks to all for advice. (I am really a bit of a worry wart)
