South West Bikers | Motorcycle Forum

As I said the other day the plug was removed from the fuel tap on my bike causing petrol to pour out. Anyway, mate has made a new one for me and when we tried to start it it wouldn't start, always starts first time usually. So he disconnected the fuel pipe from the tank to the fuel cock and theoretically petrol should have come through, but no. Do you think it might be an air lock or does the tank have to be drained. Or, is it possible for the something in the fuel tap to collapse in any way?

what bike is it? check the spark plug isnt fould up. make that ur first port of call

Funny you should say that Baskie, my mate took them out and cleaned them thoroughly, then tested them for spark and they worked ok.

why would the spark plug stop petrol from flowing out the tap???

Do you have 3 positions on your fuel tap - On, Res and Pri? if so it is a vacuum operated tap - there will be an extra hose connected either to the carbs or to the inlet rubbers to apply a vacuum to the tap - fuel wont flow in the "on" or "res" position without a vacuum (ie engine running).

If you have spark and the engine is okay, its probably lack of fuel.

Like chris said, try it on 'prime' or 'pri'

Is your bike carburated or injected?

Jonny wrote:If you have spark and the engine is okay, its probably lack of fuel.

Like chris said, try it on 'prime' or 'pri'

Is your bike carburated or injected?

Here's Jonboy learning from experiance...

born2rock86 wrote: Here's Jonboy learning from experiance...

Yep!

Well pretty much the same thing happend to me a few weeks ago, might as well share my learnings. It was nice to see an RAC man that actually knew what he was talking about, even if he was 3 hours later than promised....

baskie wrote:what bike is it? check the spark plug isnt fould up. make that ur first port of call

changing the spark plug is only the first port of call with two stroke baskie.


To be honest mate we need to know excatly what bike it is ans whether or not it has carbs or injection. As chris said if its a vacuum fuel tap then no fuel will come out unless the eengines running. It is possible for fuel taps to get blocked with crap from inside the tank or from a gasket starting to perish - but again this would be unusual on a newer bike what age is the bike??

Its a Yamaha XVS Dragstar 125. There is plenty of petrol in the tank now, but like I said in previous post the little alloy plug was out of the fuel tap. My mate made one from a bolt and welded it but still no fuel when we removed the hose to look. It has an on, prime & res on tap.

i'm not sure what the "plug" you're referring to is, pics might help. There will be two rubber hoses to the fuel tap though - one will go to the main body of the carburettor, and the other will go to either the round rubber boot that connects the carb to the engine, or to the very cap/top of the carb. Check that the hose that goes to either the rubber boot, or the top of the carburettor, is not split, blocked or disconnected - if it is, the On and Res positions wont work. in the mean time put the tap to "pri" and fuel should pour out. If it doesnt then somethings probably blocking the tap

ticketyboo2002 wrote:Funny you should say that Baskie, my mate took them out and cleaned them thoroughly, then tested them for spark and they worked ok.

FYI, If the plugs are NGK, they are notorius for not withstanding being cleaned. Might be better to replace!

Also check the breather- it think it is alloy on those, they can corrode up and prevent them breathing.