false start

[spyke]

Hi chaps
Dont know if there many of you out there on a sat night, buuut, was just out in the garage about to start her up for thevery first time after 'the build' but all i got was petrol  leaking out of my newly recond monobloc. its coming out under the union adaptor,which appeared tight enough, but there was no fibre washer under, which seems to be right after ive just checked with the book and presumably would effect the needle valve position any way? So hows this sposed to be fuel tight ? whys mine not?
Thought i was gonna have her finaly fired up tonight and all ive got is a lot of petrol on the floor on rags and on me
Cheers spyke

[1660bob]

Hi Spyke- do you mean the union on top of the float chamber where the petrol pipe attaches? If so, surely- a simple case of stuck/sunken float .If your monoblock is a new or newish one-look out for the moulding flash on the plastic float catching on the alloy screw boss in the bottom of the float chamber.Mine did when i tickled the carb a bit enthusiastically and wedged it down causing a flood!- common fault on newer monoblocs, rub off the plastic mould line with emery to cure-also newer ones have a fibre washer under the petrol union whereas older ones do not- mixing up parts will affect the float level, HTH, Bob

[spyke]

Yes bob the float needle seating, as ive just seen it referered to in another pic. If it was a stuck needle/float it should still not come out of that joint tho should it ,it would just come out of the air intake.
spyke

[1660bob]

Spyke- having re -read your query i see now you mean the union nut at the bottom of the carb. I`ll er, get me coat... I just had a look at mine and true, no fibre washer- the joint relies on a taper seat at the base of the thread to seal- it may damaged or be held off its seat by a foreign body i.e. grit or the main jet being perhaps too long/unscrewed? sounds like its not screwing up against the corresponding taper in the jet holder above- (which DOES have a fibre washer betwixt it and the carb body), Bob

[spyke]

No you were right the first time on top of the carb where the petrol pipes bolt on

[1660bob]

Back to original then!-is the petrol pipe adaptor (the bit that houses the nylon filter) crushed through overtightening- they tend to deform over time (i e collapse in at the top under the bolt, and then the clamping force on the sealing flange  on the filter is lost- the leak may be from under the  nylon filter, bob

[spyke]

Thanks Bob, you were dead right, the banjo was deformed, dished top,  when i tried another it was fine.
Only trouble was one i had was a twin inlet 55 degree 1/4" all my spares are 180 degree 5/16" as are all the ones on e-bay at mo and burlen site. Ill try draganfly in the week.
Spyke

[1660bob]

Yep, been there more than once! Some were made of  plastic  -not one of  Amal`s  greatest moments! Bob.