fuel starvation

[srutherford]

Plain and simple I ride the interstate to work every day recently I have need running out of fuel filter with a full tank I suspect the petcock my bike is a 86 1200. Also how does the run/reserve work can some one please explain in lame mans terms how this system works I am confused. Ne one had this problem thanx

Silas

[FJmonkey]

As a fellow 86' owner with fuel starvation issues. Do you use a tank bag? If not then you most likely need to perform a "flapectomy". Search this site for Klavdy's posted instructions on removing the orange flappers inside of your fuel cap. When you under take this task use a bucket or bag to prevent liberating the Nat's Balls size bearing that will shoot out and be lost forever. I have performed this and have not had any repeat issues.  My tank bag was sealing the fuel cap when wet so the material between the bag and the tank had to be changed. Actually I just stopped riding in wet weather.....

[racerman_27410]

+1 on the fuel cap vent flapper-ectomy.

the rubber gets hard and doesnt let the tank vent properly.

the bike will only exhibit these symptoms while running at speed.

KOokaloo!

[Pat Conlon]

... recently I have need running out of fuel filter with a full tank......my bike is a 86 1200.

I didn't know that the 1986 FJ's came with a fuel filter.....a screen on the petcock, yes.... A Fuel filter, no.

Didn't Yamaha first put the in line fuel filters on the '89' and later FJ's? You know, the FJ's with the fuel pumps?

I wonder why Yamaha did not put a inline fuel filter on the earlier FJ's?      Hmmmm.

Silas, if you visit the Files section, you can download a owners manual for free....That will give you some good info. you need for your bike.

[moparman70]

ur right Pat - no fuel filter on an 86 ..just the screen in the tank. 

Lots on the flapectomy in post ---heres one but I know there is more.

http://www.fjowners.com/index.php?topic=4483.msg40137#msg40137

Stevecc

[srutherford]

Well I believe further investigation has reveled. If 86 didn't have a filter then I have a take off a 89t because it has a bracket to hold one I bike ran good for 6  months I owned it all the power u want then some more just speed sat the last month there is rust in the old fired I replaced it cleaned the carbs no fuel starvation just shudders around. 5-6 grand like to lean I checked for leaks no evidence of any did I install hi jets wrong I believe it has been jetted it has a 4into 1 Vance and hines and k and n. Like I said I know it runs way better thanks

[Pat Conlon]

Sorry Silas, try as I might, I can't understand most of what you just wrote. I got the last part..."runs way better, thanks." 

[rktmanfj]

Sorry Silas, try as I might, I can't understand most of what you just wrote. I got the last part..."runs way better, thanks." 

I was just thinking the same thing.     

[srutherford]

Sorry guys my phone has mind of its own in a nut shell. It ran like a top. I let it set a month and all hell broke loose. .I believe my tank is off a 1989. Model because it has a bracket for a filter it was full of rust that's the first problem I cleaned the carbs, tank,exct. .now she shudders in mid rmp. Lean I believe I can smooth it out if I roll the throttle slowly. I am lost.  This set up was fine until she sat thanx and replaced the filter. Also off subject my oil filter housing id leaking any word of when randy will have more adapters ne one have one to sale im sick because my bike is a I hate this lmfao

[srutherford]

Well guys I believe I have solved the fuel delivery problem (fingers crossed) now that I have cleaned the carbs I have a slight sputter at mid  rpm. (Bike never had this problem) until I messed with the carbs I here is the set up stock jets I do believe (didn't see needle adjustments ) stock air box k and n filter 4-1it v and h supersport can. It seem lean because I can roll the throttle slowly to catch up and smooth it out. Any help appreciated thanx silas

[srutherford]

O and its a 86 1200

[Pat Conlon]

1) You have a gravity fed fuel system on your '86.
2) The '89's and later have a fuel pump which pulls the fuel through the filter.
3) You don't have a fuel pump on your bike.
Just because you have a '89 fuel tank with a bracket for a filter, does not mean that you should install a filter.

Again, why can't I install a filter? What's the big deal?  It is because you don't have a pump to pull the fuel through the filter.

I have found (confirmed by others) that the gravity fed FJ's ('84-87) are very fussy about restrictions in the fuel line. Very fussy.
The problem of diminished fuel flow (starvation) does not show up until kookaloo time.

All that being said, it sounds like you still have gunk in your tank, and this gunk is plugging up the small holes in your main nozzles (emulsion tubes, nozzle jets, etc.) or perhaps even clogging up your fuel filter.

Cheers!   Pat

[srutherford]

Thanx sounds like the carbs will be coming back off and if it ran fine before with this set up. Are u suggesting delete filter clean the tank and go only reason I ask is it seemed fine before its possible I didn't clean the carbs well enough I didn't dip them in ferryman like I have in the past. Half measures availed me nothing in the past why now hahajajaja how many time I have to learn that lesson

[srutherford]

Berryman for the record excuse me

[Pat Conlon]

Are u suggesting delete filter clean the tank and go only reason I ask is it seemed fine before

Yes, this is my recommendation: Delete the pleated paper fuel filter (too restrictive) and put a simple inline screen filter.
My reasoning: If you have a '89 tank, then you have a '89 petcock.
The '89+ petcocks  do not have the screen on the intake that the '84 thru 87 petcocks have (They don't need a intake screen, they have a pleated paper fuel filter and a fuel pump to suck the gas thru the pleated paper filter)
Therefore: The gravity flow bikes (84-87) have petcock a screen and you don't.
So you need one.
A simple inline fuel screen should work.... or a new '84/85 petcock with a screen.

its possible I didn't clean the carbs well enough... 

No worries Silas. I think everyone here has had to remove and replace their carbs after discovering a half ass incomplete cleaning. It's a right of passage.
Homework assignment: Read David Raforth's excellent article on carb cleaning 5 times:  http://www.fjowners.com/index.php?topic=655.0
Carefully Follow David's instructions to a T.

Half measures availed me nothing in the past....

aaah yes, Half measures availed us nothing....We stood at the turning point......Even my sponsor told me to follow David's instructions. Go figure