More Phantom "improvements"

I've been talking to Alan at PowerSportsFactory this morning, based upon some discussion of carburetors and related vacuum lines. It all started due to a post over at the Vento Users Group at Yahoo. Alan had mentioned to one of the posters that no intake manifold vacuum splitter was required as the big carburetor did not require a separate vacuum source. But my carb does have a requirement for a external vacuum source and so I ended up calling Alan to figure it all out.

I have a 26mm carburetor, not the 30mm version that is presently being offered in the big-bore kit from PSF. That explains the difference! Alan was also insistent that if I remove the u-shaped portion of the original air filter system and installed the air filter directly on the intake end of the carb that I would feel the performance improvement immediately. I used the u-shaped portion based on a picture of the kit from PSF that showed the tube included! I suppose the configuration has changed as development continues, so I'll give it a try.

The scoot has also had a problem that Alan has promised a replacement part to correct. The scooter runs out of fuel when operated at high speeds and high loads, like when I'm trying to get up some of the steep hills around my house. The motor just "dies" for a few seconds but letting up on the throttle allows the engine to recover and then it runs just dandy at everything less than wide open throttle. The fuel shut-off valve is vacuum operated and it appears to not maintain enough vacuum to hold the diaphragm open when operating under low vacuum conditions. I figured out last night how to bypass the valve tonight to verify my theory. In the mean time, Alan is shipping me a new valve.

It also just occurred to me that I could build a small vacuum storage tank to put inline to level out the changes in the low pressure level fluctuations…

The real question is, do I spend the money for that 30mm carburetor that has an accelerator pump feature? Hmm...