Jump to content

On top of ol' Smokey...


Recommended Posts

My good riding buddy is a bit timid, and asked me to post a question for him. He changed to Mobil 1 two oil changes ago in his 01 1100RT. Just a couple of weeks ago we did his 24K service. While we had it apart we replaced the Bowden box which was causing his idle speed to be erratic. All went well, but now it sporadically smokes like crazy when he first starts it up. Not all the time, and sometimes when it's been on the side stand, and sometimes when its been sitting on the center stand. I checked the air cleaner and there's no oil in the airbox. It only does it when it's cold (first start of the day) and as I said it doesn't do it every time. The oil level is at the mid range in the sight glass. Any suggestions?


I guess I should tell you that it runs very strong, with a good strong pull throughout the tach range and the top end is still there. No complaints from him other than he is now the proud owner of a 90 horsepower mosquito sprayer.

Link to comment

Depends on the nature of the smoke. White smoke that dissipates quickly might just be water vapor and of no real concern.


A darker smoke that hangs around a little longer yet still dissipates, smells a bit like gas, could be an injector is hanging up a little when cold and then operating OK once things warm up a bit. Injectors are just solenoid valves.


Another potential problem in this area is an injector that leaks just slightly. Residual fuel pressure bleeds off from the culprit leaving liquid fuel in the intake tract. Somewhat sensitive to how long the bike has been shut down and ambient temperatures.


Finally, there is oil smoke. It is persistent, smells like oil and tends to be blue/white to blue/grey. With no evidence of oil in the air box, it has to be coming from the combustion chamber. Piston rings or valve guides are the likely suspects here although these symptoms are generally not intermittent nor are they limited to cold starts. Rings tend to exhibit smoke when accelerating and valve guides tend to smoke on trailing throttle with either doing both on occasion so that is just a first place to look.

Link to comment

Considering the sage advice for sovling any problem is to "look where you last worked". I would re-load that puppy's crankcase with whatever oil was in there when it didn't smoke. If it stops then you know you might have a valve guide problem or ring problem. Syn oil is known for it's creeping action to go where others oil can't. My old truck did this with M1, smokes on start up. Went back to GTX and smoke gone. YMMV.

Cheers clap.gif


Link to comment



It is definitely oil smoke. It's pretty heavy at times, but only on initial start up. When we're riding and he hits the gas hard, no smoke from what I can see from behind.


This morning, he started it up with no smoke whatsoever. He's been running M1 for awhile now with no problems (as have I). The only thing he/we did on this last service was valves, TB synch, brake bleed and transmission linkage clean/regrease with new rubber seals. I can't think of a thing we did or changes that would cause this problem. It reminds me an old radial aircraft engine that belches smoke when fired up. Of course, that's from the oil leaking past the rings on the bottom cylinders. His bike runs much too strong to have leaking rings to this extent. Valve guides/seals maybe??

Link to comment

OK, valve guides are a likely suspect for this or valve stem oil seals, at any rate. One other possibility is the left side oil control rings may have just gotten their gaps lined up at the bottom of the cylinder and have somehow managed to stop there. Could be allowing a little oil to wander up the sides of the piston on shutdown.


Is there any correlation between sidestand/centerstand usage or time of shut down and the smoking? Any idea which cylinder? You could try shutting down in the middle of a smoke session and see which plug looks darker.

Link to comment

Thanks Ed,


I'll have him look at these posts and reply to these helpful querries himself. He did tell me today that his bike is running better than it ever has! Smooth and powerful. I'll get him up and let him give you all a more in depth history. We'll check the plugs though, next time he sprays for mosquitos.

Link to comment

My 99 RT-P does this. Oil smoke, quite random but mostly when it's been on the sidestand over a week or two which usually coincides with cold weather. When I bought the bike at a used car dealer it did this. It helped me get the price down quite a bit. That along with ABS alarm due to compromised battery strength. A new battery solved the ABS thing. The more I rode the bike the less it smoked.


The bike had BMW Synthetic in it when I bought it. I changed it to Amsoil And now have Castrol Syntec in it.


I don't worry about it anymore. I had opinions ranging form "You've got a problem" to "A lot of them do that, don't worry about it"


My bike runs great and I just inspected th Autolite spark plugs tha I put in 5,000 ago. They had a text book cafe au lait patina on them. The bike uses very little oil, I don't add any between 6k changes. Life is good.


Regards RTFink

Link to comment

I have to agree with ratfink here. My '02 with 81,000 miles runs great, uses very little oil, but......


About 1 day a month it will smoke on start up. A big cloud of smoke. Oil smoke. My theory is that occasionally the motor stops with a bit of suction in one of the cylinders. The suction draws in a bit of oil past the valves guides (or rings) and it gets burned off the next time I start the engine.


I would like to believe it's the left side since I almost always leave the bike on the side stand, but there is no supporting evidence. Plugs look clean, piston tops look identical, no oil in air box.


It does help keep the insects under control in my garage. Frankly I don't worry about it at all.



Link to comment


This topic is now archived and is closed to further replies.

  • Create New...