I See Blue Smoke - What Is It?

[Anonymous]

I have a 1981 GS550L and there's blue smoke coming from the right exhaust (cyls 3&4). The bike has not been running on a regular basis, say once every couple of weeks or so. I noticed a small bit of smoke, and I mean very little, about a month ago. Then it was sitting for two weeks. Then about two weeks ago there was a little more smoke. The bike then sat for two weeks. Yesterday, I started the bike and once she warmed up the smoke was towering right out of her. It should be noted that number four plug is oil fouled (wet) and so I'm pretty sure that number 4 is the problem.

What do I do to eliminate the problem and find out what it's gonna take to fix this beast?

Thanks,
Craig Pardy

[Anonymous]

Blue smoke = oil.

Is the blue smoke strongest when you first start the bike up? Is it missing?

Make sure you have a good strong spark to #4. Put in a new plug and see if it still smokes.

The oil can get in throught the valve stems (seals, worn guides) or past the oil control rings on the pistons.

[Anonymous]

there is very little blue smoke when I start the bike, only when it's warmed up. I put new plugs in it yesterday. I mentioned that there was oil on number 4 plug. The question is how do I find out if it came from valves or past the rings?

Craig

[Redman]

What I have always been told is that if it somke mostly on start up after sitting for a day or so then the problem is oil dripping down past valve stem oil seals while its parked. If it smokes all the time its running, another clue can be found by weiter it smokes more while under acceleration (rings) or under deceleration (valve seals). I am not an experienced mechanic, but this is what I have come to understand.

But, (after revieing your original post again) you say it smokes more after it warms up, hum..... well, I quess that goes beyound my experience. Try the accell/decell thing and report back, see what anybody else has to say.

Either way is engine work to fix. Its a matter of weither its the top end head work or if you also need to get into cyclinders/pistons.

[redliner1973]

Sounds to me like:
A....Stuck ring ( provided engine has been maintained properly)
B.....Broken Ring (Bad news)

Usually you can tell if it is a ring when you do a wet/dry compression test. Warm engine, shut off. Remove plug, install guage. Check at WOT. take reading. Squirt 1 tbsp oil in cyl. turn over about 3 or 4 revolutions. take another reading. if compression is now higher, bad ring. if same, usually valve stem. I am leaning more to stuck ring by your postinfg of letting bike sit and it smoking a little more each time. Valve seals also take time to leak, but usually all start to go, not just one. Yo also said the plug was oil fouled. Valve guides/seals usually won't foul a plug much at all. rings will splash one down pretty quick. try some flush or idle with kerosene in the crankcase. change oil and see if it goes away. post back and let us know whats up. :twisted:

[Anonymous]

Okay guys, here's an update.

I went and started the bike tonight and there was plenty of blue smoke. I added a can of engine tune-up (wynn's) to the oil, which claimed to free sticky rings and valves. I then proceeded to take the bike for a 10 minute ride. By the time I got back the bike was smoking much less. I then did an oil change to get all that crap out of the engine. A lot of gunky stuff came out in the oil change. After that I took the bike for a run for about half an hour on the highway. By the time I got back the bike was not smoking at all at idle and smoked very-very little when the bike was revved to high rpm's while sitting.

Where to go from here?

[Anonymous]

Might have been a stuch oil control ring. In any case - nice job.