NC24 fuel starvation...

[veefer400]

Got the above happening whilst on full throttle - is fine pottering around, in town etc - will be fine for a minute then the motor die's like its run out of fuel, will pick up again if the throttle is shut for a while, altho a particulary illegal bid today caused me to coast to a halt...
The bike started fine after 10 mins, does this on reserve as well...

Im thinking the filter is blocked - can anyone tell me if it is in the wide bore pipe from the fuel tap??

(Thinking about it this has started after I refitted the small bore pipe to the fuel tap after taking the tank off to check the state of the air filter, to my mind this has never been connected whilst I have had the bike - is this some sort of vacuum pipe??)

[castrol101]

The vacuum pipe attatches to the small bore pipe pointing directly down from the fuel tap. If the bike runs without this attatched the tap has been modded, (spring removed) so fuel flows regardless.

Drain the tank, remove the twisty (on/off/reserve) bit with a screwdriver and undo the 2 bolts holding the tap to the tank, and the fuel filter will come out as one piece attatched to the fuel tap.

If your bike does have a vacuum hose attatched ( i was'nt clear whether it did) then check if for holes all the way along, as this would cause fuel starvation especially at higher revs i believe

[Neosophist]

If your bike does have a vacuum hose attatched ( i was'nt clear whether it did) then check if for holes all the way along, as this would cause fuel starvation especially at higher revs i believe

+1

Mine had a split in it and was causing fuel starvation at higher revs.

[veefer400]

Im sure the vacuum pipe wasnt attached before I had the tank off to check what state the filter was in?? Found it just lying there?? Just remembered I reattached the petrol tank breather hose to the t junction halway down the side of the tank, this could also cause a vacuum in the tank if this is blocked?? Will disconnect it again before work tomoz....

[veefer400]

Still getting grief - have unplugged the tank breather pipe from the t-junction by the side of the pipe - will take the tank off later and check the state of the vacuum pipe.... am I right in thinking if I remove the spring out of the tap the tap will work as a normal tap and I can plug the vacuum hose??

Just seems a bit overcomplicated for a fuel tap!

[fastdruid]

Still getting grief - have unplugged the tank breather pipe from the t-junction by the side of the pipe - will take the tank off later and check the state of the vacuum pipe.... am I right in thinking if I remove the spring out of the tap the tap will work as a normal tap and I can plug the vacuum hose??

Just seems a bit overcomplicated for a fuel tap!

Pretty much yes, I wouldn't though.

I've wrecked an engine before through converting the tap to a non vacuum tap then leaving the tap on and the needle valves obviously not sealing 100% (over about 5 weeks). Filled the sump with petrol, it blew a big end bearing 9 miles later (after an oil change too).

Druid

[fastdruid]

If your bike does have a vacuum hose attatched ( i was'nt clear whether it did) then check if for holes all the way along, as this would cause fuel starvation especially at higher revs i believe

+1

Mine had a split in it and was causing fuel starvation at higher revs.

Ours had issues when the end split and I cut it down slightly, the pipe ended up slightly kinked.
Make sure yours isn't trapped or kinked.

Druid

[veefer400]

SORTED!! :D

Checked the vacuum hose - all good??

Opened the tap up - to find a big split in the diaphragm....

http://i109.photobucket.com/albums/n61/ ... C02066.jpg" onclick="window.open(this.href);return false;

No wonder..... have removed the spring for the meantime, will order a new diaphragm if poss from Mr.Silver....

[Neosophist]

If your bike does have a vacuum hose attatched ( i was'nt clear whether it did) then check if for holes all the way along, as this would cause fuel starvation especially at higher revs i believe

+1

Mine had a split in it and was causing fuel starvation at higher revs.

Ours had issues when the end split and I cut it down slightly, the pipe ended up slightly kinked.
Make sure yours isn't trapped or kinked.

Druid

Mine did the same thing when I cut it down so I had to re-route it not to kink (it was a get me home from the middle of the A14) replaces all the rubber hoses after that.

[fastdruid]

Yeah, that'd do it!

Druid