grey/white smoke on decell

[first timer]

OK guys, what does it mean when i get a good amout of grey / white smoke, (not blue) on the decell of my bike, it is more noticeable on the decell after i give it a good hard accell.

is it a valve problem or a ring issue or a over rich carb issue? and what would be the remedy. and how bad is it to continue to ride the bike like this.

this is the first time i have logged any serious miles (400) on my 79 gs1000 after it's resurection, and never touch the motor other then basics (shims, cam chain replacement, oil, filter, oil pan de gunking and oil sump screen check/clean).

thanks,
-ryan

[West]

Usually blowing smoke on decel is blowby past the rings. Run a a compression test & then again after squirting a little oil into the cylinders. If the numbers improve significantly it's your rings.

Shouldn't hurt it (anymore) to ride it.

[BadBillyB]

I would suspect that your valve seals are at fault here. On a decel there is very high engine vacuum. If the intake valve seals are bad, high vacuum pulls the oil right past them. Bad rings usually cause smoking under hard acceleration. If you just logged 400 miles, check your oil level, its bound to be low. A overly rich condition would give you black smoke. Do a hard decel and chop the motor and pull a plug.....BadBillyB

[West]

I stand corrected. Listen to Billy.

[first timer]

i know it is the #2 cylinder, the plug is a glossy black the rest look the color they need to be. yes, the oil level was low and i have been getting a lower compresstion reading on the #2 cylinder as well, but this was without doing a leak down test. i was waiting to do another compresstion test until i was able to put some miles on it, so that anything that was sticking like rings and crusty carbon on valves would work them selfs free, so i could get a better reading. Now that i have put 400 good miles on it, i think anything that was sticking or built up should be free by now. So i will go and do another test and see what i get.

so what would the remedies be? do i need to pull the head to do the guides maybe valves? how much would that cost if i was to do it myself. If it's loose rings, i guess i would need to at least rehone and re-ring the #2 cylinder. but it would be better to do all 4 or just go with a wiseco kit....

-ryan

[jgordon]

Depends on what shape your cylinders nad pistons are in. I would re-ring it no matter what and have a reputable shop do a valve job if it needs it...and.....replace the valve stem seals.

[first timer]

billy you have any more input?

-ryan

[BadBillyB]

If it were mine, I would check the compression (on a warmed up motor w/throttle open), write down the readings. Re-check any readings that are suspect and then do a leak down test to check the integrity of the valves and seats. If the leakdown test reveals any leakage past the valves, then pull the valve cover and make sure the offending valve has clearance. The results of these checks would determine the course of the repair...I am putting off the major engine repair on mine until the weather gets too cold to ride. My GS1000 w/30K miles burns oil at a pretty good rate but runs well enough to ride and doesn't smoke so bad that I am embarrased.....BadBillyB

[Nessism]

Billy's got this one covered. My comment relates to his 1000 burning oil after 30,000 miles. Some people with 850/1000/1100 motors seem to get big mileage out of them but others don't. The valve adjustment issue (or lack of adjustment I should say leading to burned valves) looms large in the life of these motors but others just seem to wear out the cylinder/rings. Any explaination for this?

[first timer]

sounds like mine, i will do just what you said this weekend or next and get back to you, i'll pm you with the results. i may want your advise on go fast parts for under 1000 bucks if the motor ends up needing love.

thanks,
ryan

[BadBillyB]

Billy's got this one covered. My comment relates to his 1000 burning oil after 30,000 miles. Some people with 850/1000/1100 motors seem to get big mileage out of them but others don't. The valve adjustment issue (or lack of adjustment I should say leading to burned valves) looms large in the life of these motors but others just seem to wear out the cylinder/rings. Any explaination for this?

It's all about maintenance. Frequent oil changes and quality air filters are at the top of the list. I blame mine on PO's as I have only had it for a year. ...BadBillyB