Fuel line too long?

[ezza]

howdy, wondering if someone who knows more than me can tell me if an 8mm fuel line at 4 metres long may be too long for a small old 9.5 hp johnson?
Have just finished building a 3.7 mtr composite and have located the fuel tank right up the bow with a chase tube and 8mm line. First splash yesterday and after finding the motor would only run for a minute or two before starving, we figured she would run if my mate sat up the bow and pumped the primer.
haha - was a good afternoon putting around nudgee and dropping a line, but rather funny haveing to manually pump the fuel.

Anyway - thoughts? Should i pull through some 10mm line or should i look elsewhere for my problem?
I'd really like to leave the tank up front for balance and space.

thanks all.

[MyWay]

should not be problem check your breader screw is loose on fuel tank

[ezza]

breather screw - yep, definately checked that.
she is an old but well looked after motor... 70's vintage i think.
can the fuel pump diaphrams wear out?

[Chimo]

Yes they can or the spring on either side can let go which is what happend to tw of mine.

Cheers
Chimo

[Guido]

Yeah, shouldn't be a problem. We have our 20L tank up the nose of our 3.7 tinny under a casting deck. We've just run the hose along the top lip of the hull to the motor (so the crabs don't nip the line!). It might be 10mm...not too sure. We had a 6hp Johnson, mid 90's. Now has a late 90's 9.9 Yamaha. Never had trouble with either of them.

Guido

[ezza]

ok gotcha guys, i'll check motor end of things.
cheers.

[Roughasguts]

Maybe your fuel bulb should be at the other end nearest the motor. Cause that little fuel pump has to pull the fuel past the non return valve, and it be easier for it to do if closer the the pump where the highest suction will be.

Cheers.

[ezza]

FIXED - thanks all.
In the end it turned out to be a disintegrated fuel pump cork gasket.
Replaced and runs so well now.... however.....

Maybe someone can help me with this one... now that she runs ok, when we wind up the revs I find it pops out of fwd gear anything over half throttle.
Have checked linkages etc and am pretty sure we have a worn clutch dog.
Now.... where on earth do I find one of those for an old Johnson 9.5 - around early 60's vintage?
Any ideas at all and i'm in your debt hehe!

[dreemon]

I would be looking for a replacment from a wreckers, I think the repair could be costly, good luck