by Warkton Tornado No.1 » Sun Apr 07, 2024 3:10 pm
Dell'Orto manufracture excellent components to enable good calibration to be achieved.
(IMHO the round slide carburetor is best left for four stroke engines they were designed for, but Dell'Orto have done an excellent job in allowing/marketing the PH series to be useable with a two stroke engine. Any know!edge/experience I have personally has been the result of setting up engines already fitted with Dell'Orto's of all varieties, including conversion of VHB's to operate with PH atomisers, needles & - in particular - the needle shroud)
Despite any apparent cynicism, in the interests of attempting to help, I would make the following observations in addition to the excellent advice already received.
The Post Originator is prepared to spend money in an attempt to make for a better running engine. That's good, but prior to shelling out for a new s!ide, consideration should be given to.modifying the 40 s!ide to a (more likely suitable) 45. This is easily accomplished with hand files & the knowledge of the difference between a 40 & a 50 etc. I can't say for.certain if it is actually a millimetre without checking, but whatever the amount, it can very easily be seen that a, say, '42-1/2' etc s!ide can be fashioned. Perhaps some kind reader with more than one slide size would confirm the variation?
What I would advocate is the procurement of a smaller atomiser to enable more accurate fuel control. It appears to be very popular to have greater size atomisers than those necessary fitted in Lambretta engines.....If in doubt, remove the main jet completely & try revving the engine out - most likely a lot of engines will run happily on a 262.....Hopefully the OP has a mate with a choice of atomiser......
Finally, as a matter of precaution, a larger float valve would be sensible. No need to go mad, but a safety factor that a valve greater than 200 provides is worth the expense, bearing in mind that once we get this puppy jogging along a bit more like intended, it can be a factor often overlooked.
Generally, a pilot of around 50 is a good starting.
By the way, had anybody noticed, I'm back.....