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General Category => Yamaha FJ1100 / FJ1200 Running Problems => Topic started by: europe50 on September 27, 2009, 03:28:59 PM

Title: Smoking at start-up...
Post by: europe50 on September 27, 2009, 03:28:59 PM
Hey guys,
I am new to the site and looking forward to push all of your knowledge a little, again.
I have a 1986 FJ1200 with 26k miles and at first start-up the bike seems to smoke allot, but stops and doesn't come back until after sitting for a while (Couple days).
The bike did sit for a couple of years and I was wondering if valve seals/valve guilds are a common problem?
Thanks!
Dean
Northern Chicago, Ill
Title: Re: Smoking at start-up...
Post by: Fred on September 27, 2009, 05:07:29 PM
Remember it is an almost 25 year old bike, so it could easily be the valve seals, guides a little less likely particularly with that low mileage. If you wanted to be real thorough about it, you could do a compression check and eliminate the rings, but I wouldn't think it would be that since the smoke stops. If you haven't ridden much you might want go out and have a good ride, seems to do an FJ a lot of good. Like a wise man told me nothing makes THem run like running them.
Hope that helps, YMMV, and I break peg brackets, so take it for what its worth.

Fred
Title: Re: Smoking at start-up...
Post by: xt550 on September 28, 2009, 12:44:06 PM
typically bad valve seals generate smoke when the engine is "rewing" down.
when the carburettor is closed the vacum sucks oil down.
My bike does this, the mechanic i talk to said that when he was racing in the late -70th they removed them for better cooling and lubrication.
So it's not that dangerous if you don't run dry.
The valve seals also seams to dry if the bike is standing still for some time (years) and get hard and maby brake.

A tip about compression tests is take one test than drop some oil in the cylinder and then redo the test if you get a higher value the second time the oil has sealed the rings if not, valves or something else is leaking.
Title: Re: Smoking at start-up...
Post by: SlowOldGuy on September 28, 2009, 01:05:43 PM
Solution = Don't let it sit for a few days.  :-)

Sounds like valve guide seals.  Mine did the same thing until I replaced the seals last year.  No more start-up smoke after that.

DavidR.
Title: Re: Smoking at start-up...
Post by: europe50 on September 28, 2009, 05:45:25 PM
Thanks for all the helps guys!