Engine Smokes after warm-up

[priley88]

Hi Everyone, I have an 84 FJ 1100 that I picked up a few weeks back and have been getting it running again.  Thus far, I have cleaned the carbs (removed them, stripped them down to the bodies and butterflies, and soaked in Sea Foam), put in new spark plugs and a new air filter, reinstalled the carbs and set up a manometer to sync the carbs after install.  Also, I have an older gas tank with a smidge of rust inside but am running a fuel filter in line.  It has about 21000 miles on the odometer, and the old oil was clear when I changed the oil and filter. The bike runs fairly smoothly and I can take it around a few blocks, though it doesn't have the grunt I have heard is typical for a well-running 1100

Currently, it will start with choke but doesn't require choke after a few minutes.  Once it has warmed up, it starts to smoke, a LOT.  Looks like grey smoke coming out the exhaust pipes and a small bit around the #1 cylinder (far left) exhaust port.  Also, the throttle seems to hang up at high RPMs after revving, even up to 5000.  I'll stop and restart the bike, and it will continue to rev high like this.
Any pointers on 1.) what the cause of the smoke after warm-up is?

2.) what causes the high revs?  I'm thinking improperly lubricated throttle linkage vs stuck throttle cable vs manifold air leak. 
Thanks in advance for the help!
Cheers,

Pete

[Bones]

What did the old plugs you pulled out look like, were they dry or oily. How much oil did you put in after the oil change, you didn't put too much in. Is there somewhere you can take the bike and give it a good thrash, the rings might be stuck in the grooves and giving the motor a good workout might loosen them so they reseat.

The high revs could be from any of the things you said, might pay to go through and check everything and do a process of elimination. Check your mixture screws as well, they can make the revs hang if not adjusted properly.

[ribbert]

o

[mr blackstock]

G'day,

Another thing to check..compression.  If you do not have a compression tester just remove the plugs and stick your finger firmly into the sparkplug hole, turn the bike over and if the compression is good in that cylinder, your finger should "pop" out from the pressure.  If your finger does not pop out much, or at all, it may indicate that your rings are buggered in that cylinder.

If you have good compression the issue may be leaking valve seal or guide, and oil may have leaked into your header pipe and is burning off as it gets hotter.  Does the smoking subside after a period of time?  I have not seen this happen, but you never know.  If you remove the exhaust pipe you would see an oil smear from the valve guide.

Just some thoughts, happy hunting

Cheers, Gareth

[priley88]

Hi Everyone, thanks very much for the responses!  Sorry for the delay on my end.  Bones and Ribbert, I think you two were spot on for the high idle and the smoke.  I rechecked the oil level, and it definitely seems like I was a bit overzealous refilling it after the oil change...the level was definitely high, and the next time I ran it it continued to have white smoke.  Eventually though the smoke disappeared, and the oil level appears to be within normal limits... looks like she may have fixed herself, whoops! Oil level is normal now, and no more of that white smoke with which to disrupt the neighbors.  Until the next can of sea foam, that is...

Also, one of my throttle cables was definitely loose.  I tightened up both cables to within stock tolerances (5mm of throttle "wiggle" if I recall correctly), and also adjusted the idle screw, and it settled right out.  Has pretty snappy throttle response and idles a smidge above 1k on the bike tach, pretty smoothly.  I still want to check the mixture screws, as the idle is hanging a little bit (for a half - one second) before settling back to normal.

Also, finally got the chance to really wind her up on a straightaway.  It's got great acceleration down low but my god it's like a rocket once you cross 5000.  Sound about right for the powerband?

Thanks Gareth; problem seems to have resolved currently but I will plan to check compression just to cover all the bases; not sure when the last time it was checked on this machine.

Thanks again for all of the help guys; I am consistently amazed at the generosity and knowledge of everyone on here.
Cheers, and safe riding!