'84 fj1100

[twangin4u]

Runs great after first start. Then after warms up it runs like crap. After maybe 3 miles or less. Starts cutting out, backfiring, sputtering, and eventually dies. Always the same. If I give it full throttle when it's cutting out it will usually take off like it should but starts backfiring again when I let off throttle. Does anyone know what size I.d. the curled fuel line is. I went to Napa and shoved a 5/16 bolt down the line to see and it fit snugly. The ends are flared out where they have been attached to the fittings. I just bought this bike from a friend. He said they put sea foam or some shit in it. Dumb if you ask me. I have checked the routing of the fuel lines more than twice and I don't see any pinches or kinks


. Makes me begin to wonder if that sea foam is a form of oil then I know what oil does to rubber lines. Swells them up. Maybe it's restricted the fuel flow to the carbs? I don't but it's pissing me off. Lol

[Pat Conlon]

Clean your carbs, specifically the idle circuit and the pilot jets....

See the Files for guidance.

The size of the fuel hose will only matter at WFO and not at the engine speeds you are experiencing your problems.

[twangin4u]

I sure will. Thanks man, and I'll let you know.

[FJmonkey]

Seafoam has not affected my fuel lines and it helps keep the jets and carbs clean. However, I need to run the bike one every 3 weeks or risk gumming up the idle jets. Which sounds exactly like what you are describing when my jets are clogged. I have had some luck just running a tank or to of Seafoam to clear the jets, but if they are really clogged, you need to pull them and do a proper cleaning.

[Pat Conlon]

..... I have checked the routing of the fuel lines more than twice and I don't see any pinches or kinks

It is vitally important to have the correct fuel line route on your bike. If the line route is incorrect what happens is when the engine heats up the fuel line softens and a kink will occur, starving the carbs of fuel (sound familiar?)

The proper fuel line route is counter intuitive. You look at it and say to yourself..."that can't be right.." but it is.

The single fuel line as it leaves the petcock should run *under* the 2 branch lines that feeds carbs 1/2 and 3/4.
When you put your tank back on, what you can't see is that the petcock outlet is below the level of the 2 branch lines which is why you will pinch the single fuel line (when it heats up) if you run this line over the branch lines.

It's a bit harder to reconnect the fuel line to the tank petcock when routed the correct way. Everyone seems to have their own technique.
What I do is stand on the left side of the bike, seat the tank on the neck grommets, wiggle it into place, and then lean over the tank and look in from the right side and with my right hand I lift the back of the tank up about 3" or so..enough to see under the tank and get my left hand in there to first connect the petcock vacuum line, then connect to the petcock outlet the short stub of the main fuel line (again, which runs under the branch lines). You can also put a block of wood to hold the back of tank up, but I find that not necessary...you only have room to put one hand under the tank anyway.

Hope this helps.

[twangin4u]

Yeah, the fuel line was routed over the branch and I switched it earlier today. However with the same results. So far I have torn into the carbs and they look pretty darn clean. I have to go down and get a better Phillips cause a couple of these machine screw's are friggin tight as hell. I did however come across this which make me cringe.

**it's what appears to be a little tear in the diaphragm. It's the first one I took off so far. Gulp

[twangin4u]

Any suggestion of how I can avoid buying a new diaphragm. I see they are proud of those little buggers

[Urban_Legend]

http://www.fjowners.com/index.php?topic=5340.0

Found this link (above) hope it helps

Mark

[twangin4u]

Plasti-dip it is. Thanks mark

[twangin4u]

Is that the same stuff that's called dip-it? For dipping plier handles into to give them a soft rubber grip? Wonder where in town I could find some?

[FJmonkey]

Where in the world are you?

[copper]

Those a JIS screws not just any ole' phillips

[Pat Conlon]

Throw those JIS Phillips away and get thee a ss Allen kit (and carb o ring kit) from RPM

A good investment.

[twangin4u]

I found some. Good ol harbor freight. Where quality is number 1. Lol!!
I found my problem too. Under the little screen below the flat needle on all for carbs was a was of gunk. So I'm double fisting a couple keystones in an early celebration. Yay! :hicup:

[Urban_Legend]

Mmmmmm beer. It fixes lots of things.