350x oil cumsumption question

[Yamaha_Rules69]

Went riding with a buddy today on my 85 Honda 350x. Before riding, I checked the oil, and topped it off to the correct mark. We were riding for about 5 hours. I thought the machine ran great througout the ride. When we got down to the last part of the ride, he said he could see and smell a blue smoke cloud behing me, at the time we were riding slow. I looked back and saw it, and decided to get it home. I pulled the dip stick, and just a little oil left on the bottom of the dipstick. I looked back from time to time, and didnt notice any smoke prior to the incodent. I reved it up once I got home, and didnt notice any smoke. There are no oil leaks anywhere on the motor, so where is the oil going? If I had to guess, it burned at least a quart of oil. It has real good compression at the kicker, no doubt about that. I just picked this up a couple months ago, and already have a lot of money in parts and labor into it. I was thinking it was a dependable rider until now. I have only ridden it a few times, and it seems to run great. --- Jon.

[yaegerb]

have you let it sit for a while to get the oil back to the sump and then checked it again?

[Yamaha_Rules69]

Yes, the motor was just warm to the touch when I checked it after the ride (sat for 20-30 minutes)

[yaegerb]

sounds to me like its either the valve seals or the rings or maybe both. I don't know how else you would be eating that much oil otherwise...unless you are leaking oil from the cases.

[whyzee]

Blue smoke on acceleration is a sign of worn rings.

[dougspcs]

Compression test is the best way to tell the health of your motor.

Your compression could be off 30psi and it would still run well and have lots of power.

If it's off the mark it's time for some top-end work..been there, done that. Do it right and you have another 25 years of riding!!

[Yamaha_Rules69]

Alright, I'll do the compression test, and see what it reads. Its funny, because all the smaller honda engines I have rebuilt - 185, 200 s and x, both smoked all the time, and upon rebuild, it was worn piston rings. I had the cylinders bored to the next size, and put in new piston and rings, and never had a smoking problem with them again, they are all running, and have a lot of hours put on them too. I'll let you guys know what I find. --- Jon.