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General Category => Yamaha FJ1100 / FJ1200 Running Problems => Topic started by: gilangie on August 12, 2010, 07:26:40 AM

Title: 1987 FJ1200, runs out of fuel with more than half a tank of petrol available
Post by: gilangie on August 12, 2010, 07:26:40 AM
Hi,

my name is Gil, I have just bought a reconditioned FJ1200 (1987) - my second, I sold my first one 14 years ago and despite owning and riding plenty of bikes since then I have never ridden a bike like the FJ since - first ride was a 950km trip home in 11 hours. 

For some reason the bike seems to run out of fuel with the tank more than half full.  It runs perfectly right up to around 170km and then coughs and splutters then dies, refilling the tank fixes the problem immediately.  After it has died there is clearly plenty of fuel sloshing around in the tank.

The previous owner has replaced the reserve switch but this did not fix the problem.

Any ideas team?

Regards

Gil
Title: Re: 1987 FJ1200, runs out of fuel with more than half a tank of petrol available
Post by: weymouth399 on August 12, 2010, 08:11:42 AM
Hi Gil

#1 Check if there is a aftermarket fuel filter in line they normaly don't like it.
Racer 111v has put two filters on his 86 with good results.
#2 Check if your gas cap is venting correctly try having a spare key and crack the cap while riding, carefully.
#3 Check all fuel lines to and from petcock, they can split. Also check for kinked hoses.
Hope this helps
Bob
Title: Re: 1987 FJ1200, runs out of fuel with more than half a tank of petrol available
Post by: fj1250 on August 12, 2010, 05:12:40 PM
What was your fuel gauge reading (indicating) when you ran out of fuel.
How much fuel did it take (in gallons if you can)to refill the tank from the point of running out?
The petcock on this bike is regulated by the fuel gauge. If the gauge reads near empty, the servo in the petcock is shut off so the bike acts like it's running out of fuel unless you flip to reserve.

MC
Title: Re: 1987 FJ1200, runs out of fuel with more than half a tank of petrol available
Post by: FJmonkey on August 12, 2010, 07:19:38 PM
I ran out of fuel with almost a full tank (in the rain). My tank bag sealed to the tank from the water getting under the neoprene pad. Cap could not vent and the tank went into vacuum preventing the gravity feed system from feeding the hungry carbs (70+ mph). I pulled the bag, checked that I had a full tank, put it back on and it started right up. 10 minutes later same thing. I stuffed some rags under the bag to keep the cap exposed and venting, no problems the remainder of the trip. Might want to take the cap apart and pull the orange little flapper parts out. If you disassemble the cap, go slow and careful and do it in a bucket to catch the very tiny ball that shoots/falls out. There is guide on this simple modification in the files section. Good luck. Let us know what worked.
Title: Re: 1987 FJ1200, runs out of fuel with more than half a tank of petrol available
Post by: racerman_27410 on August 12, 2010, 08:24:10 PM
+1 for removing the flapper valves in the gas cap......  :good2:


KOokaloo!
Title: Re: 1987 FJ1200, runs out of fuel with more than half a tank of petrol available
Post by: Mark Olson on August 14, 2010, 02:49:42 PM
I have an 86 that will run out of gas when I use a tank bag on it as well.

only does it on hot days or big elevation changes.

I just lift the tank bag for a minute while riding and keep on going.

one of these days I will fix the flapper. :wacko3: