XR 600 still smoking

[AzXr628]

95 XR600 has been smoking since I feel over.So I rebuilt my top end new valve seals and valves.put it all togeather and it still smoking.So does anyone have any ideas what it could be before I pull it apart again.

[don87xr600]

rings?

[AzXr628]

So have you had this happen to you.

We did a compression check and it was good,Then put oil on top and it was higher.

It only smokes heavy after sitting angle doesn't matter on the stand or oppsite on the bar.

[mgs781]

Did you deburr the valve stems before you put it back together?

[AzXr628]

Cant say i I took the head off but the shop put the new parts in and I put the head back togeather

[bork]

If oil in cylinder when doing comp test makes lbs go higher then your rings are worn . Does your dipstick show any loss after riding ? an hour ?

[AzXr628]

I have never checked the oil other then before a ride.

New question if you have a high volume of crank case breather can you get oil in through any part of the head or carb?or a clogged oil tank breather tube And could this be why I'm burning oil.

Yes I'm looking at the manual and reaching for any hope not to pull the engine down again

[truck6driver]

I ran into this problem after a rebuild also. The engine builder did not see the piston index mark and had it 180 out. Apparently the piston has more oiling holes in the oil control ring groove at the rear of the piston. When it was turned around it would allow oil to get on top of the piston. Also it did reduce the amount of oil the the rear of the piston got. Oil smoke and compression loss was the reason It was pulled back apart. A new piston, a re-hone and rings fixed the problem.

RH

[bootlegger2]

if the breather tubes are clogged with dirt or whatever this can cause smoking

i would have to say it would be rings if that is not the case especialy if you put oil in there while checking

does it not smoke when you lean it the other way

and does it smoke all the time or just when you start it up

all the time meaning while you are riding

[AzXr628]

Well here is the rest of the story,Took the head back off,then removed the cylinder to find the 628 bore kit.now for the bad news,the piston was the wrong size and the oil ring you could shave with.so the only thing to do is put a 640 bore kit and all the matching parts.No wonder it smoked.

So when you think that used bike is a steal,step back and that a good long think about it.I should have guess by the shop that was consigning it was a dump and the manager made rocks look smart.