PHBH Atomiser

[Mike-Allen]

Hi all,

Sure I've read on here somewhere on a thread but can't remember where but am I right in thinking that selecting the correct atomiser can be done by removing the main jet & seeing if it revs through? If it does this indicates a need to go up a size on the atomiser? take it this can be done regardless of what needle is currently installed?

Thanks
Mike

[Warkton Tornado No.1]

Hi all,

Sure I've read on here somewhere on a thread but can't remember where but am I right in thinking that selecting the correct atomiser can be done by removing the main jet & seeing if it revs through? If it does this indicates a need to go up a size on the atomiser? take it this can be done regardless of what needle is currently installed?

Thanks
Mike

You are scientifically correct, but the idea is to attempt to find the smallest atomiser that will function, bearing in mind that it should only be able to serve the largest main jet likely to be fitted to an engine. When Dell'Orto's only affordable carburettor was the VHB for those of us racing in the 70's, the method was applied so that no greater than necessary atomisers were fitted to competition engines, enabling finer tuning. After removing the main jet, if the engine was so rich it was barely rideable for a paddock check, the chances would be that a smaller atomiser could be substituted.

Nowadays the mathematical formula is available via the Dell'Orto tuning/function pdf's. Similarly float valve size information is printed.

From the atomisers quoted on this Forum, it appears customary to have a larger atomiser than I would think necessary.

[Mike-Allen]

Thanks for the reply