New to me 91 ST1100 blowing blue smoke

John OoSTerhuis · Jul 20, 2015

The oil level is checked with the ST on the centerstand.

USA '91s have an external crankcase breather chamber (right side by the tip over bar). All other years', they're internal. The 91s' breather hose runs to the bottom right side of the air cleaner. Check the hole in the bottom of the air cleaner for venting crankcase air and oil. In the three cases of blocked crankcase venting that I know of, the pressure and oil blew by the valve cover gaskets though. Doesn't sound like your problem.

bonth123 · Jul 20, 2015

I finally got all the plastic off...24 years has taken its toll on mounting tabs and correct screws. The airfilter was literally dripping with oil, and the plugs are all black and soot covered, so I think I have sucked oil in somehow. I started it for a few seconds to see if not having the airfilter would clear up the oil smoke, it is less but still very much there.

Does anyone know of an inexpensive compression tester kit that has a fittin for these bikes, the one I bought I had to return since it doesn't fit our spark plug holes.

Thanks

dwalby · Jul 20, 2015

bonth123 said:
I finally got all the plastic off...24 years has taken its toll on mounting tabs and correct screws. The airfilter was literally dripping with oil, and the plugs are all black and soot covered, so I think I have sucked oil in somehow. I started it for a few seconds to see if not having the airfilter would clear up the oil smoke, it is less but still very much there.

Does anyone know of an inexpensive compression tester kit that has a fittin for these bikes, the one I bought I had to return since it doesn't fit our spark plug holes.

Thanks

Don't know about the plug size options, but AutoZone will loan you a compression tester for free.

bonth123 · Jul 20, 2015

I tried theirs but it didn't have a fitting for my bike. I will locate one on Amazon or somewhere and order it...they aren't very much.

moddy · Jul 21, 2015

Sorry I didn't catch you in time. I bought a compression tester because the adapters throughout one for automotive didn't have one needed for the 1100.

bonth123 · Jul 21, 2015

moddy said:
Sorry I didn't catch you in time. I bought a compression tester because the adapters throughout one for automotive didn't have one needed for the 1100.

Can you tell me the brand and model?

Thanks

moddy · Jul 21, 2015

bonth123 said:
Can you tell me the brand and model?

Thanks

OTC 5604 Motorcycle Compression Tester Kit

I don't remember using it before a minor blockage in carb #3 was detected. But I know the this one would not fit when I ordered it but needed it anyway. OTC 5606 Compression Tester[h=1][/h]

bonth123 · Jul 21, 2015

Thanks

John OoSTerhuis · Jul 21, 2015

moddy said:
OTC 5604 Motorcycle Compression Tester Kit

I don't remember using it before a minor blockage in carb #3 was detected. But I know the this one would not fit when I ordered it but needed it anyway. OTC 5606 Compression Tester[h=1][/h]

Hi Moddy. Just to confirm - the OTC 5604 does work on the ST1100, the 5606 model doesn't, correct?

Would you consider loaning yours out to fellow STriders?

Regards, John
via iPhone 6

bonth123 · Jul 21, 2015

I just purchased the 5605 and will loan it if needed, after I get mine sorted of course. Also, I see that my oil level is completely past the level of the glass so I need to change it and get it back to where it should be, any suggestions on filter brands and whether or not this could cause my blowing of oil smoke after 120 miles of no problems?

Thanks

schlep1967 · Jul 21, 2015

bonth123 said:
I see that my oil level is completely past the level of the glass so I need to change it and get it back to where it should be,

Are you saying it is over full or low. If it is over full you may have found your problem.

playinatwork · Jul 21, 2015

I'm no expert but it sure sounds to me like it was just overfilled with oil. Replace the oil, oil filter, and air filter and run a tank thru it. You'll want to replace the plugs if that was the problem.

afrymoyer · Jul 21, 2015

See if the oil smells like gasoline. It's possible that a stuck open carb float would flood the engine and overfill the crankcase.

lti_57 · Jul 21, 2015

All my Guzz's would blow out any excess Oil when i got on it hard then let off. It would soon find its happy level.
there is only so much volume in the crank case its got to go somewhere

dwalby · Jul 21, 2015

lti_57 said:
All my Guzz's would blow out any excess Oil when i got on it hard then let off. It would soon find its happy level.
there is only so much volume in the crank case its got to go somewhere

which is consistent with his symptom of oil in the air filter housing, I think it gets blown there through the crankcase vent hose. But how would you explain the burning oil coming out of the exhaust? I don't see how overfilling the oil level could cause that, and it wouldn't explain how it started smoking all at once if it was overfilled when he started the ride.

lti_57 · Jul 21, 2015

My experience was this. I was about 40-50 miles into a ride, with a group. I saw a wide sweeper and I got on it hard passed a few of my riding buddies let off saw the cloud behind me
It was enough that when we stopped for lunch my new Guzzi was the brunt of jokes.
But after it found its happy spot it never did it again.

schlep1967 · Jul 21, 2015

dwalby said:
which is consistent with his symptom of oil in the air filter housing, I think it gets blown there through the crankcase vent hose. But how would you explain the burning oil coming out of the exhaust? I don't see how overfilling the oil level could cause that, and it wouldn't explain how it started smoking all at once if it was overfilled when he started the ride.

When it gets enough in the air filter it will then go into the fuel air mixture in the carbs and then into the combustion chambers.

dwalby · Jul 21, 2015

schlep1967 said:
When it gets enough in the air filter it will then go into the fuel air mixture in the carbs and then into the combustion chambers.

yep, I just realized that a few minutes before I read this post. The filter housing starts out dry, so there's a lag between the start of the ride and the onset of the smoking. Makes sense now, I didn't realize it could blow that much oil up into the filter housing that it would ingest it into the carbs and cylinders. That must be really overfilled.

bonth123 · Jul 22, 2015

I think if I had not increased speed it may not have sucked oil up, or it was a very slow process that finally showed. The air filter was very wet with fresh oil. I'm changing the oil and the very nasty plus and see if the does it.

dwalby · Jul 22, 2015

bonth123 said:
I think if I had not increased speed it may not have sucked oil up, or it was a very slow process that finally showed. The air filter was very wet with fresh oil. I'm changing the oil and the very nasty plus and see if the does it.

yeah, I'm hoping that will fix it, good luck. BTW, the oil ingestion from the filter housing is also consistent with your symptom that all the plugs are fouled, as opposed to just one or two if your head gasket had blown. That plus the fact that we rarely hear about head gasket failures here is a good sign.

New to me 91 ST1100 blowing blue smoke

John OoSTerhuis

Life Is Good!

bonth123

dwalby

bonth123

moddy

the mod

bonth123

moddy

the mod

bonth123

John OoSTerhuis

Life Is Good!

bonth123

schlep1967

Bill

playinatwork

afrymoyer

lti_57

Above the center of the Earth

dwalby

lti_57

Above the center of the Earth

schlep1967

Bill

dwalby

bonth123

dwalby