1991 fj1200 smoking after warm up

[Ndulucky13]

Just bought a fj1200 that sat for 2 years only has 14k miles on it.  Has been down once by previous owner light crash at 15mph.  Got it home cleaned the carbs went to start it and gas ran out of the overflow tube for carb 4 and the main overflow like a steady stream it was strange. Got it started agin with gas tank not connected and it ran for about 2 mins no smoke then started getting worse and worse so i shut it off.  Any ideas?

[ribbert]

Just bought a fj1200 that sat for 2 years only has 14k miles on it.  Has been down once by previous owner light crash at 15mph.  Got it home cleaned the carbs went to start it and gas ran out of the overflow tube for carb 4 and the main overflow like a steady stream it was strange. Got it started agin with gas tank not connected and it ran for about 2 mins no smoke then started getting worse and worse so i shut it off.  Any ideas?

A big rev, a hard ride or a few sharp raps on the bowl of the offending carby with something metallic with a bit of weight to it should do the trick (assuming they have been re assembled correctly)
If all that fails, you will have to remove them again and inspect. They are very simple and not much to got wrong with them.
At that mileage, nothing should be worn out.

The FJ's are prone to random, intermittent episodes of this anyway.

Noel

[movenon]

As a thought if your carbs or carb is leaking then smoke might just be from a to rich condition. They say,  and generally it is true that blue smoke is oil and black is fuel but in the real world for me anyhow it is hard to really say that as an absolute.  Shades of grey .  Fix the carbs or carb

Also if it has been sitting for 2 years most of the oil in the top end (valve stem seals) have probably leaked most of the oil down that they could and when you started it up new fresh warm oil was pumped back up to the top end and leaking down the old seals.  Or could be a ring seating issue. In any case I would fix the leaking carb and just watch it put 500-1000 miles on her and then reevaluate. Don't panic and don't assume the worse case. It is all fixable..
 
George

[FJmonkey]

The smoking off the engine is most commonly caused by either the valve cover grommets or valve cover seal. But since it has not run for two years you may need to burn off whatever has accumulated. It won't hurt to get a flashlight and look around the engine for signs of oil leaks. Mostly on the front and left side where most of the oil seals are located. If it smoking out of the exhaust then it may just need to burn off the oil from sitting so long.

[Pat Conlon]

Welcome Lucky...

When you say you "cleaned the carbs" did you really clean the carbs?
Did you completely disassemble them and thoroughly clean, or just spray some cleaner?
Follow this procedure? http://www.fjowners.com/index.php?topic=655.0

Here's some advice on common carb leaks: http://www.fjowners.com/index.php?topic=46.0
Common carb gas leaks are from the float needle seat O rings, so replace those, then sync your carbs, check your valve clearances and adjust if necessary. While the valve cover is off, replace the valve cover bolt grommets (common oil leakers) then then ride it.

Assuming the oil smoke was not from an external leak (valve cover) it sounds like you have a dry valve seal which can clear up with some miles.

Don't let that air cooled motor sit and idle for too long....It will overheat. You will cook an exhaust valve.

Cheers

[Ndulucky13]

Thank you guys for all help I will pull them again and recheck orings I was worried it was rings and that meant rebuild time. 

[FJmonkey]

Thank you guys for all help I will pull them again and recheck orings I was worried it was rings and that meant rebuild time. 

If you are going to dive back in the carbs you might as well order a new set of O-rings and know that they are good. Unless you like removing and opening your carbs.

[Ndulucky13]

Also  no smoke was coming off the motor just out the exhaust when I would rev it, it would shoot out smoke smelled like oil.  I really hope one of ghe rings just needs to seat I'll change oil tonight and pull and check carbs again.

[Ndulucky13]

Good news!  Pulled the carbs and found that the float pins were slightly sticky thus the floats were sticking open.  Fixed that and checked compression while I was in there 150psi across the board so that seems good.
Smoke is now gone after oil change and first ride.  Thanks guys for the advice I followed the carb rebuilding pdf it runs like a top!  Now I have to figure out this horrible buzzing in the fairing

[PaulG]

Now I have to figure out this horrible buzzing in the fairing

Welcome to the club in more ways than one... 

Buzziness?

1) Is it rpm related or speed related

2) How old are the tires? If it's been sitting for 2 yrs they may have flat spotted, also check for age and uneven tread wear etc.

3) Make sure all the mounting screws etc. are there and tight.

4) Hows the condition of the chain and sprockets.

5) When you rebuilt the carbs did you balance/synch them?

6) Are the original bar weights on or are they aftermarket.

7) The motor mounts may or probably do need removing and cleaning and lubing. (I just went through this).  I`m assuming it has the rubber mounted engine of course.

You seem to be able to figure this stuff out very quickly with an apparent level of mechanical skill, so I hope my queries don`t sound redundundant.  You tore the carbs apart-serviced them-re installed-and tested in 24hrs.  I know a lot of members here could do the same but for me that ususally takes....  well I`d rather not say...     Japanese I-4s have an inherent tendency to be buzzy anyhow, so it`s a matter of mitigating the vibes as much as possible to a manageable level, as opposed to eliminating them.

Being an `old` bike it will probably have some hard to trace rattles.  I used to get a real buzz-on around 4,000rpm that was wrist numbing.  After removing and lubing the motor mounts that has pretty much disappeared.  I was then getting a vibration up through the seat around 3,000rpm.  After balancing the carbs that is now minimal.  At idle my r-side upper fairing along the windshield and mirror rattles but smooths out once the bike gets rolling.

Good to see you getting her back on the road rather than languishing in despair in storage.  The more miles these bikes get, the happier they seem to be.  More like a sled dog than a motorcycle.

Hey!  I think I just gave mine a name!  Sled Dog!  Gaarrooowwwlllllllwwhhhoooooo....    Sorry - didn`t mean to hijack your thread 

Now if I could get this painted on the bike somewheres....

[ribbert]

Now I have to figure out this horrible buzzing in the fairing

Buzziness, as distinct from vibration on a '91 will always be seized front engine mounts. Many other things can cause lower frequency and softer vibes but the mounts are what causes the buzziness.

It's a waste of time chasing the noise until you fix the cause. When I first got my bike I had the fairing off every other weekend chasing it. I'd fix one and it would start somewhere else. I packed everything with tape to no avail. When the engine mount fix became known and I did it, I never had another noise.

Folks who have done this fix cannot believe the difference, the smoothness. These late model FJ engines are smoother than a lot of current 4's on the market now, particularly at cruising revs.

There is tons of references here for the job and plenty of people that can give you pointers.

Noel

[Ndulucky13]

A little history I have owned a lot of bikes this fj makes number 57 and I have worked on over a hundred different bikes. Being only 26 sometimes people look down at me (what could a 26 year old know?) on certain forums so I don't mention it often ha.  Each bike has its good and bads I don't really hate on any.  I do have a new problem though the buzz is still there at exactly 3k rpm I will definitely try the motor mount fix tomorrow.  The new problem is the bike will start and run awesome but once warmed up (I took it for a ride) the idle wants to hang at 2k rpm I can make it come back down with letting the clutch out in gear and bringing it back down.  I have synced the carbs with my vaccum gauges and sprayed cleaner around the boots to check for cracks or leaks found nothing. I'm a bit stumped why it hangs there. Any common things to check?

[ribbert]

........The new problem is the bike will start and run awesome but once warmed up (I took it for a ride) the idle wants to hang at 2k rpm I can make it come back down with letting the clutch out in gear and bringing it back down.  I have synced the carbs with my vaccum gauges and sprayed cleaner around the boots to check for cracks or leaks found nothing. I'm a bit stumped why it hangs there. Any common things to check?

First thing to check is that it's not mechanical.
If you've had the carbies off, you've had the cables off.
If there is not enough slack at the throttle it can disappear when the bike gets hot, preventing the carb linkage fully returning to the stop.

Easiest way to check is to push down hard on the linkage (at the adjustment screw) and see if the revs drop.

Given the sequence of events and timing of this new problem, I'd be looking there first.

Noel

[Pat Conlon]

Yep, rule out mechanical first, a hanging idle on a warm bike is a indication of richness.
Try turning your idle mixture screws in 1/4 turn, see if that helps.

[a.graham52]

My bike did something similar. It would hang up until I brought it down like you did. Then it would idle fine until I revved it again. Mine was the vacuum advance for emissions causing my grief. Plug the hose that goes to it and see if your problem goes away