smoke at high rpm

[King400]

Just took over a 2001 TRX400EX. Quick starting, idles well and runs good. When I took out the plastics to give it a run through for repairs, everything seems to be ok but the right tie rod which was slightly bent, Replaced tie rods and made some alignments and it was ok. I checked the oil and it was very low. Drained and replaced oil filter but when I ran it this time, bluish white smoke was coming out of the OEM exhaust at high rpm. This was after the oil change and replacing the open(no discs and blank plate)White Bros. E- Series exhaust with the OEM exhaust with spark arrestor. I followed the manual instruction of 1.95 qt. 10-40w oil and ran it for 5 minutes and a dip stick check. It's showing me oil all the way up to the "full' marker. I hope the smoke is not due to an oil ring or piston ring problem. Again, the smoke was not there even on high rpm when the old oil was low in the tank. Did I put too much oil and it is overflowing to the chamber, thus the smoke at high rpm? Please help!:confused:
Thanks ya'll and glad to find this forum and hope to stay here.

[brodzowski]

The blueish smoke is ONLY at high RPM right? Silly, you're running too rich! If you took an aftermarket pipe off and corked it up with the stocker and it only smokes at high rpm, you need to rejet back to stock numbers on the carb.

[richards]

edit - here is the oil checking procedure quoted from the service manual:


Place the vehicle on level ground.
Start the engine and let it idle for a 5 minutes. If the air temperature is below 10°C (50"FL let the engine idle for an additional 5 minutes (a total of 10 minutes).
Stop the engine.
After a few minutes, remove the oil filler cap/dipstick from the oil tank and wipe it clean.
Check the oil level by inserting the oil filler/dipstick into the oil filler hole without screwing it in.

If oil level is correct then I'm thinking you have worn rings and/or worn valve guides or valve stem seals.

If it is smoking pretty bad then it would be a good idea to pull the head and cylinder, then check the ring end gap and also take a look at the valve stem seals.

If it is not smoking too bad then you could ignore it for a while, it should not cause any serious trouble unless you let the oil level get too low. You could be loosing some power though due to the rings being worn.

[richards]

Originally posted by brodzowski
The blueish smoke is ONLY at high RPM right? Silly, you're running too rich! If you took an aftermarket pipe off and corked it up with the stocker and it only smokes at high rpm, you need to rejet back to stock numbers on the carb.

That's a great point - I missed the bit about going back to stock exhaust. Could be the main is too large and it is rich at WOT.

[King400]

Where exactly should the oil level be if checked without threading while the motor is idling?:confused: And thank you guys for pitching in! Will a leaking muffler gasket cause this bluish smoke at high rpm too?

[richards]

Originally posted by King400
Where exactly should the oil level be if checked without threading while the motor is idling?

I was wrong about the idling bit, I edited my post above. The quote from the shop manual should answer your question I think.