82 GS650G blowing blue smoke

[skidMarkNZ]

Hey guys. took my bike for a testrun before i bought her the other day, all was well.

Went out for a ride with flatmate following on sunday and he said it blew slight amounts of blue smoke on accelleration, and more so on decelleration.

So i got home took plugs out and showed them to flatmate, #1's plug was quite dirty and black, all 3 others were perfect, good amount of ash etc.


yanked motor out, old wise flatmate come out and goes.

You should have tried new oil and plugs first, it may have come right. (what can i say i like to tinker) haha

Is he right on this, becuase right now after just forking out for the bike i do not have the funds to buy new rings and a gasket kit.

So do i just do an oil change and new plugs, Or do i leave it in garage and wait until i have the money to do the above? Which i assume it need rings and valve guide stem seals, and of course all the new gaskets (but the stem seals come with gasket kit)

I really dont see how an oil change may stop it burning oil. in saying this i have only just got it and i think she has been neglected, so could be 20,000 k's since last oil change for all i know.

bike has 41,000 k's total.

Cheers in advance.

Mark.

[tkent02]

How's the compression? Use much oil?
What do clean plugs look like after a ride?
How well does it run?
If it has sat a while, change the oil, go out and ride it, a lot.
It might get better, it might not.
But don't take it apart until you have the funds for repairs, at least it's ridable now.

Dirty and black sounds like too much fuel, wet shiny and black is oil.

[Griffin]

You might try squirting a small amount of ATF into the offending cylinder and letting it sit overnight. If you have a stuck ring, it might loosen it up enough to improve the seal.

I agree, change the oil, ride it a bit at varying rpm, and see if you can't get it to seal up better before tearing into her. I got a 750 last year that had pretty crappy compression across the board (under 100 psi in each cylinder) because it had been sitting for eight years. It smoked a tiny bit at first too. I've ridden it over 1,500 miles, some of them pretty hard too, and now compression is over 140 psi, with no smoke. It's used about 1/2 a quart of oil in that time, none over the past 500 or so miles.

[skidMarkNZ]

Yeah i did a 200 kilometer ride (about 120 miles) flatmate said it was smoking the whole time, i know it has been sitting for at least a month, because the guy i bought it off owned it for a month and never rode it because it was more cosmetically sad than he wanted to fix, the previous owner owned her for 10 years, i cannot see the smoke myself, but my flatmate said it would be very minimal amounts. there is lots of black oil carbon in the exhaust though.

Currently the motor is out but not been ripped into, so i can just drop her back in if i want to.

[skidMarkNZ]

How's the compression? Use much oil?
What do clean plugs look like after a ride?
How well does it run?
If it has sat a while, change the oil, go out and ride it, a lot.
It might get better, it might not.
But don't take it apart until you have the funds for repairs, at least it's ridable now.

Dirty and black sounds like too much fuel, wet shiny and black is oil.

Compression, no idea i do not have a tester, but still goes like fark lol. i dont know how much poil it is using as i have only done approx 120 miles on her.

seems to run fine apart from running on 3 sometimes, just a crook/ dirty plug i think.

Yeah i just dont want to ride her then find she goes bang, then im really stuffed! lol

cheers

[tkent02]

Compression, no idea i do not have a tester, but still goes like fark lol. i dont know how much poil it is using as i have only done approx 120 miles on her.

seems to run fine apart from running on 3 sometimes, just a crook/ dirty plug i think.

Yeah i just dont want to ride her then find she goes bang, then im really stuffed! lol

cheers

Do this, try Griffin's idea about the ATF, or use Marvel Mystery Oil, or an equivalent product. Adjust the valves, go through the carbs, fix any airleaks, adjust the timing, use new plugs, change the oil and then put it back in and ride it. A little puff of smoke here and there won't make it go bang.

[TheCafeKid]

Do this, try Griffin's idea about the ATF, or use Marvel Mystery Oil, or an equivalent product. Adjust the valves, go through the carbs, fix any airleaks, adjust the timing, use new plugs, change the oil and then put it back in and ride it. A little puff of smoke here and there won't make it go bang.

Nope..it wont. And depending on WHEN its puffing smoke can tell you WHERE its leaking usually too. Generally its been MY experience that if its blowing smoke under acceleration, its the rings, and on decel, its the valve seals. Its possible to be either or under either condition, but if your seals are leaking on accel, they're REALLY leaking...

[skidMarkNZ]

Nope..it wont. And depending on WHEN its puffing smoke can tell you WHERE its leaking usually too. Generally its been MY experience that if its blowing smoke under acceleration, its the rings, and on decel, its the valve seals. Its possible to be either or under either condition, but if your seals are leaking on accel, they're REALLY leaking...

Yeah they said it was sod all blue smoke, but enough that it was noticable, leaving a light haze behind. okay will try what was said in the other post too, but ahhh, what is ATF, automatic transmisison fluid? how will it help loosen it up if it is a stuck ring? thanks for the help guys, dumb questions i know haha.

Thanks again: Mark.

EDIT i also have a feeling the smoke under decel could just be the throttle blips on my downchanges.

[tkent02]

Not sure why, maybe it has a lot of detergents or something?
It seems to work, it's a very old trick.

[Griffin]

Yeah they said it was sod all blue smoke, but enough that it was noticable, leaving a light haze behind. okay will try what was said in the other post too, but ahhh, what is ATF, automatic transmisison fluid? how will it help loosen it up if it is a stuck ring? thanks for the help guys, dumb questions i know haha.

Thanks again: Mark.

ATF is indeed tranny fluid. It has some nice anti-rust properties to it, and is slicker than dog spit. Marvel Mystery oil, 3 in 1 oil, etc.. all work too. I recommended ATF because it's cheap and you can get it anywhere.

Unburnt fuel has a distinctive odor to it, slightly petrol like with a bit of a burning smell in it too. Burning oil has more of a robust, foul smell to it. If you're only firing on three from time to time, it could (hopefully) be unburnt fuel from the compression chamber making its way into the hot exhaust pipe, then being partially burned there before exiting out the exhaust in a wet vapor.

[TheCafeKid]

ATF is indeed tranny fluid. It has some nice anti-rust properties to it, and is slicker than dog spit. Marvel Mystery oil, 3 in 1 oil, etc.. all work too. I recommended ATF because it's cheap and you can get it anywhere.

Unburnt fuel has a distinctive odor to it, slightly petrol like with a bit of a burning smell in it too. Burning oil has more of a robust, foul smell to it. If you're only firing on three from time to time, it could (hopefully) be unburnt fuel from the compression chamber making its way into the hot exhaust pipe, then being partially burned there before exiting out the exhaust in a wet vapor.

Unburnt fuel also tends to be a bit more wispy and black than oil. Oil obviously is heavy and blue.

[skidMarkNZ]

I was told it was definately blue oil smoke.

They said under accel when i gave it a bit of a handful i think, last cylinder seemed to like kicking in around 5k or so.

so maybe it was building up in that cylinder
then when i went for it it all came out?

If it was unburnt fuel id go yeah it will be the number 1 not firing, but #1's plug is alot sootier looking than the others. and they say it is def blue smoke (i feel like such a newbie asking this stuff haha)

[Steve]

If it seemed to run on 4 when in the upper rpm ranges, you might also have a (slightly) plugged carb. The pilot circuit meters fuel in the lower rpm/throttle ranges, so if that is plugged and the cylinder is not firing well, there might be a bit of unburned oil collecting in the combustion chamber, which is then released as smoke when you transition into the main jets.

.

[skidMarkNZ]

Well, i changed oil and plugs and oil filter...

Still smokes, failed WOF (warrent of fitness) due to being too smoky.

Gasket kit and pistons and rings to be ordered

DOH.