40mm Dellorto Float height

[customhead]

I have overhauled the carby from a Gilera 500 and found the float had let a lot of fuel thru overflow and into the cylinder.
luckily i could hear it and removed sparkplug for safety.

BUT! The Gilera Saturno manual says the float height should be 24+/-2mm
My Dellorto manual says PHM carbys are to be set at 18.5 - 17.5

it would seem dellorto is incorrect seeing as I have overflow.

Anyone have experience with this problem?


Sean

[Joachim]

if i remeber right i have always used the value from the Gilera manual.
So maybe you should give that one a chance
On the other hand, the fuel valve is ok? Not leaking? New?

ciao Joachim

[lambs]

I have overhauled the carby from a Gilera 500 and found the float had let a lot of fuel thru overflow and into the cylinder.
luckily i could hear it and removed sparkplug for safety.

If you haven't already, suggest changing the float needle (+ seat, if its of the replaceable type). The new type float needles use a viton rubber tip, which is better for modern fuels.

BUT! The Gilera Saturno manual says the float height should be 24+/-2mm
My Dellorto manual says PHM carbys are to be set at 18.5 - 17.5

it would seem dellorto is incorrect seeing as I have overflow.

I'd tend to stick to the Gilera manual spec but, yes, the dellorto manual float height spec would lead to a higher fuel level in the float bowl and consequent richer mixture. However, overflow shouldn't occur if the needle and seat are in good condition.

[customhead]

the tip is viton and whilst changing things is always better, the condition looks good.

I will stick to the Gilera manual although "Turn over the carburettor and let float rest on the needle's damper"
annoys me as there is more than one way to turn a carburettor

[lambs]

the tip is viton and whilst changing things is always better, the condition looks good.

Looks like the seat is also replaceable on the PHM, so something to consider if problems persist.

I will stick to the Gilera manual although "Turn over the carburettor and let float rest on the needle's damper"
annoys me as there is more than one way to turn a carburettor

This might help:

http://www.thisoldtractor.com/dellorto_ ... etors.html