Post by toddmaples on May 21, 2017 21:53:45 GMT -5
i have to disagree with the added weight though.
i'm pretty sure if you add weight to the diaphram, scooter performance will suffer.
add enough weight and it won't open at all.
the question is, how much is too much, especially for a temporary fix.
that is something i can't answer.
i've had my carb apart a few times and i didn't run across an accelerator pump.
it had an air cutoff valve that eliminated backfires on closed throttle and an "enrichener" (choke).
i had a 250 though.
On some carbs there is a shaft behing the throttle linkage, this is the accelerator 'pump' its really just a diaphram that pulls gas from the bowl and squirts it through a small orifice when the throttle is twisted.
www.scrappydogscooters.com/site/d4faf33a669343abab34a17e8762cbe3/139qmb-50cc-performanc-1?url=http%3A%2F%2Fwww.scrappydogscooters.com%2F139QMB_50cc_Performance.html#2725
Look at scrappys 20mm carb, the black boot behind the throttle linkage protects the shaft, it goes through the housing and has a diaphram in the bottom where the red plug is barely visible in the pic. Take two screws loose from the botton side and it will pop right out.
Put the new diaphram in from the donor carb today, and no more leak. The old one had a pinhole tear right near the shaft causing my leaking gas. Ordered a new diaphram from partsforscooters to go in the donor to use as a spare. As far as i can tell all these cvk pumper catbs use the same size diaphram for the pumper. Now to tune my intake length and straighten out this no-spark issue over the next two days...