1986 fj1200 Help Please

[stroscoach]

OK I have posted this before , and Have tried all suggestions and now I am ready to rides this f'er off a cliff. Hears the problem I can ride all day long bike runs great after a quick stop maybe twenty mins or so get back on starts up fine runs fine for a couple miles then shuts down like its running out of fuel . I have : taken out the flappers , cleaned out the tank , changed the fuel hoses to a beefer fuel inj hose carefully routing the hoses correctly . I can feel it in throttle response prior to completely shutting down and if open the fuel cap it seems to run better so I think it still a fuel problem. Hopefully someone out there in fj land can give me a solution. This bike is awesome to ride but this problem takes the fun out of riding. thanks  again

[Travis398]

Are you saying it runs fine when the tank is full, and then acts up as the tank level gets lower?

[FJmonkey]

You say you performed the flapectomy, still have the problem, but the problem is not as bad with the cap cracked open. The evidence clearly indicates that some of the problem is still the cap not venting properly. Possible blocked passage inside the cap. Have you noticed what the fuel level is each time you had this? Does it seem to happen with a full tank? Near empty? Does it always happen after sitting like you mentioned? Being able to duplicate/cause the problem to happen really helps. We can focus on all the conditions and eliminate them one by one. Your fuel hose is not OEM, sitting on top of the carbs with the heat from the engine warming up the hose might chance how the hose behaves. Cold, it maybe stiff enough to not kink, warm it up and maybe it kinks a little. While you are running you are getting air moving through and keeping the heat down. Try to borrow an OEM hose from a working bike.  Your problem can be solved, save the cliff for genuine lost causes.

[Pat Conlon]

The '86/87's had that wacky electric reserve petcock.
This POS petcock has stranded more than a few FJ'ers, including a test rider for a motorcycle mag who was doing a review on the '86 FJ's.
When this happens, try lifting the tank and switching the petcock to "prime" position to see if the gas starts flowing to your motor. Wear gloves it will be hot under the tank.  Perhaps what is happening is that thru a electrical fault, your petcock is somehow going on reserve.

Don't give up.   Cheers.   Pat

[tqmx1]

Pat, me bucko the 86/7 do not have a prime position, just the two wires coming out of it.

Off subject, How are you and the 84 getting aloung?

Kim

[Pat Conlon]

Hey Kim, thx, I didn't know that about the electric petcocks. Sounds like a stupid design.   (Kim PM sent)  Pat

[edit] ....so if there is a interruption of vacuum to this petcock, there is no way to manually turn on the gas?  Really?  Hard to believe.   

[stroscoach]

Are you saying it runs fine when the tank is full, and then acts up as the tank level gets lower?
runs fine at all levels until i ride for awhile and stop for a brief time 20 min to hr get back on and 2 miles down the rode it quits

[stroscoach]

You say you performed the flapectomy, still have the problem, but the problem is not as bad with the cap cracked open. The evidence clearly indicates that some of the problem is still the cap not venting properly. Possible blocked passage inside the cap. Have you noticed what the fuel level is each time you had this? Does it seem to happen with a full tank? Near empty? Does it always happen after sitting like you mentioned? Being able to duplicate/cause the problem to happen really helps. We can focus on all the conditions and eliminate them one by one. Your fuel hose is not OEM, sitting on top of the carbs with the heat from the engine warming up the hose might chance how the hose behaves. Cold, it maybe stiff enough to not kink, warm it up and maybe it kinks a little. While you are running you are getting air moving through and keeping the heat down. Try to borrow an OEM hose from a working bike.  Your problem can be solved, save the cliff for genuine lost causes.
it happens at any fuel level and only when I ride stop and ride again within say an hour . I have this nice run of about forty miles with a small country store in the middle of it I stop there have a smoke  and a coffee get back on and every time it shuts down almost in the exact same spot pop the cap it starts after a couple of cranks and away I go. It had this clear plastic tubing for fuel line when I got it so I thought that might be the problem so I changed it with some heavy duty fuel Injection Hose but it still happening  Its got to be a venting problem just dont know what to try next I took the cap apart a couple of times all channels and holes seem to be open I guess I will get some oe hoses from the dealer and seehow that goes thanks I appreciate your Input

[stroscoach]

The '86/87's had that wacky electric reserve petcock.
This POS petcock has stranded more than a few FJ'ers, including a test rider for a motorcycle mag who was doing a review on the '86 FJ's.
When this happens, try lifting the tank and switching the petcock to "prime" position to see if the gas starts flowing to your motor. Wear gloves it will be hot under the tank.  Perhaps what is happening is that thru a electrical fault, your petcock is somehow going on reserve.

Don't give up.   Cheers.   Pat
I have switched to prime and it has started back up , but it has also shut down on the prime setting in the same way. My petcock is vacuum operated it doesn't have any  electrical wires going to it. Thanks  I appreciate your input

[Flying Scotsman]

If you have a inline fuel filter thats a little dirty it might run good then bad.I would buy a new filter if you run a inline filter.

[56 CHEVY]

I had the exact same problem with my 86 FJ1200 several years ago and I understand your pain. I tried everything from replacing the relay for the reserve, performing the "flapectomy", changing hoses, ect. What finally fixed the problem was replacing the entire fuel petcock assy. I never did figure out why the old one would act up but I have put around 25000 miles on it since it was replaced with out the problem ever happening again. It was expensive at the time but worth it to me.

Good luck

[moparman70]

Had an 86 ( still do technically) -

First- do your ride as you are and then when you stop - ride with the gas cap open for as long as you think it would take for it normally to stop.  If it does not stop  -- then

Instead of the flapectomy - what I did ( prior to knowing about flapectomy ) Is I cut the seal to the tank - put a little notch in at 12:00 oclock if you are looking at the cap.  The notch was about 2 mm - and just allows direct venting --- I never had any gas come out even when full and I put more than 40K miles on it since the mod.

In the meantime -- check out the petcock - it comes a part easily and replace the spring and o-ring -- I am not sure where you can get the spring but the O-ring is available at any NaPa or like parts store.  It is a metric size so get the one that fits best if you don't have the old one to compare.  If you can find the spring - expand the old one to give it more range when compressed.

The petcocks work but in a funny way - reserve and such I won't get into ( there are posts on it if you search) -- but bottomline - under vacuum the seal in the assy sucks the plunger back that the O-ring is on and allows fuel to flow.  You could have a break in the vacuum seal and it may not be pulling back on the plunger enough but I would think that it would happen all the time and not just after a ride.

The cutting of the seal worked for me -- I never had any vapour locks after that.

stevecc