RB20 spitting fuel....everywhere

[James]

Have a RB20 built by AF and dynoed by Prodesign so I know it's running right, however it's mega thirsty and spits fuel everywhere which really p's me off, running a AF road pipe and 34mm Dellorto, runs real nice and am getting 24BHP which is fine but forever cleaning the running boards, did the IOW last year with a mate on a TS1240 and I used nearly double the fuel.
Any advice would be helpful or is this just the way the RB's are??

[rosscla]

A reed kit shouldn't spit fuel everywhere.

I presume your mate with the TS1 doesn't have the same mess?

Check your reeds.

The spit back is caused when there is positive pressure in the inlet port and is pretty common in piston ported motors , if the reed is working / closed properly that vapour shouldn't make it out of the carb.

[jonashford]

Try a different carb, the 34 may be too big for the rb 20, have u checked the reeds?

[garry inglis]

I have the 30vhsh on mine as the 34 is a bit overkill no spit back 10 miles per litre and from tickover it picks up a lot better and better for town use just had it dynod 20.5hp at 79rpm revs on to 85rpm

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[LeightonRB20]

Mine is running a 34mm Dellorto too and is also spitting. New, smaller carb required then? I'm probably getting 5/6 miles per litre.

[garry inglis]

Rayspeed £200 and Ben will jet it for you and you also get the rubber with circlips great value and great service

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[diesel]

Rayspeed £200

What do Rayspeed do for £200?

[garry inglis]

30mm vhsh carb

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[diesel]

I would have known had I read your post properly, sorry

[garry inglis]

No problems

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