I think I'm running a bit rich...

A comp or leak down test won't necessarily determine an oil issue, IMO, a comp test wont tell you if your oil rings are bad, and since the valves are closed during a leak down it's not going to identify bad stem seals or guides. Are you certain the bike isn't 8 stroking somewhere in the throttle range?

"A comp or leak down test won't necessarily determine an oil issue, IMO, a comp test wont tell you if your oil rings are bad, and since the valves are closed during a leak down it's not going to identify bad stem seals or guides."



Truth.

Ron Hulton said:

Opinions are always welcome ... Can the rings be that bad if i have 175 psi compression on both sides ? By adding the oil to each cylinder , i eliminated ring gap . For what i know , if you have a gap in your rings ...air will get by. Although the rings should have bedded in by now , and then again . ??

Cheers

Click to expand...

Are you positive that the rings are right side up? You're plugs look like oil to me, not rich. Upside down rings will still seal but they will also pump oil into the combustion chamber. If you have a borescope, run it a little, remove the plugs, put the scope in and slowly turn over by hand - any oil streaks on the cylinder walls?

I'm way out of my depth compared to some of the folks who are pitching in here, so take with a grain of salt, but....

175 psi, and uniform between cylinders? Sounds pretty good to me (assuming an accurate compression gauge - and in any event, the fact that they're the same is encouraging).

If you're burning oil, it's usually pretty easy to tell - by smell! Received wisdom as I understand it points to valve guides if detected while idling, rings if during acceleration.

Case in point, my wife used to complain of, um, two-stroke syndrome, when following me when I first got my Commando. A set of new rings fixed that (and the exhaust pulses, scientifically measured by holding my hand a foot or so behind each exhaust pipe outlet, confirmed a very noticeable increase in the "percussion," for lack of a better word, of the exhaust-gas pulses).

Best of luck.

I have not had much experience with motors which use a lot of oil. But when the motor is running, you should be able to see it in the exhaust - and in any case, if you run your finger around the inside of the exhaust pipe outlet, it would come out greasey. With plugs which come out black, I would lower the needles in the carbs. If the needles are already in the top notch, I would fit the smaller needle jets. Another thing which can cause flooding and thus richness is excessive vibration.

What oil have you used while running the rings in ? A friend of mine tried running in a rebuilt cortina engine on modern semi synthetic oil . The rings wouldn't bed in. Had to resort to cheap old style oil . The modern oil was too slippery! Once the smoke had stopped he did a change to the good stuff . Roy.

JSMotorsports sells great teflon valve seals . Just an idea , worked for me .