Triumphrat

bigbird · 12-14-2005

Hi guys
just been doing some check on my 900 sprint and on taking the tank off, i found i coundn't turn off the fuel. I've turned the tap to all positions and still the fuel came.
My question is, should you be able to? if so any ideas to what i'm doing wrong or could be wrong.
cheers all...

Gromit3528 · 12-14-2005

Hi Bigbird

There is not an off position on the tap because the tap should usually be automatically off when the engine is not running. There is a small diameter tube running from the back of the tap to a small spigot on the top of the right hand carb. This is under a vacuum when the engine is running and this vacuum causes the tap to open. When the bike has been stood for a while the fuel evaporates from the carbs so there is insufficient in them for the engine to start. In this situation turning the tap to Prime (PRI) position opens the tap regardless of the vacuum allowing the carbs to fill and the engine to start. Once the engine is running you should turn the tap back to the ON position so that the fuel supply is again controlled by the vacuum.

Please forgive me if I'm teaching you to suck eggs here!

What I suspect has happened is that the plastic fuel tap knob has broken (as they are prone to do) The moulded flat that engages on the flat on the tap spindle has broken off. This allows the knob to rotate on the taps spindle instead of turning it. Unfortunately this feels exactly like the tap is working properly. You will probably find that the tap is actually set to the prime position but rotating the knob to any other position has no effect on the tap.
I hope I'm right, but having found this on two Trophys recently I'm fairly confident. Unfortunately the new Knob has not been modified to eliminate this problem so you just have to be careful with it in future.

Regards

bigbird · 12-14-2005

cheers gromit

That what i thought, so i took off the knob, and turned the tap itself. But still fuel flows through in all positions.I took to tap to bits (I know its not wise as bits are hard to get)and the white plastic washer behind the bit of the tap that you turn was stuck in the prime position( i think).I've freed it up but still no joy.
I think it could be knackered.I will have another go at it, nothing to lose.
Thanks Gromit

sailfish · 12-14-2005

Mr. Bird,

I had the same problem last summer. The tap should close on it's own with no vacuum pulling it open. I'm suprised that you're disassembly didn't work. I carefully disassembled and reassembled mine and all is good...till the next time. You might try a light, rubber compatable lubricant to get things moving again.

Regards,
Mr. Fish

SpitfireTriple · 12-26-2005

Gromit said:

What I suspect has happened is that the plastic fuel tap knob has broken (as they are prone to do) The moulded flat that engages on the flat on the tap spindle has broken off. This allows the knob to rotate on the taps spindle instead of turning it. Unfortunately this feels exactly like the tap is working properly. You will probably find that the tap is actually set to the prime position but rotating the knob to any other position has no effect on the tap.

I agree, and posted a similar reply recently on a Daytona Deliberations thread. I found a way to stop the problem happening ever again (I hope). I think the thread name was Daytona 900 - suddenly controlled by evil sprits (!)
http://www.triumphrat.net/modules.ph...=6707&forum=22

Odd that the fuel still flows even after removing the knob and turning the shaft "manually" (with a pair of pliers?

[ This message was edited by: SpitfireTriple on 2005-12-26 10:35 ]

bigbird · 01-14-2006

hi guys,sorry its been a while

I found the problem, under the plastic knob is a metal tap which is held in by 2 screws, if you take this out you'll see 2 lugs that engage a nylon washer inside the tap.

these lugs had broken off. The fix was a second hand tap for £10 . all sorted.

cheers all........