Recent content by Bach Pham Thien

Hi. Thanks for replying. I did try installing the stock pump but it overflows the carburetor so I ordered a replacement exactly like that from the manufacturer (SYM). Still overflows though. Any idea on how to lower the fuel pressure acting on the float and the needle valve? I am using 6mm ID...

I have read some articles online and taking in new information about fuel flow and fuel pressure. I figure maybe the fuel pressure is too much for the float to handle? Maybe I can try a bigger inner diameter fuel hose to try lower the pressure?

Thanks but my carburetor is also a new one so I suspect it might be the bigger piston and higher compression somehow making the vacuum pump stronger.

Good morning, I am new to the forum, so let me get straight into the problem. I am working on an old scooter with small displacement (150cc, with about 9.6:1 compression ratio). After rebuilding the engine, I figured I have to put in a much bigger piston 60mm compared to the original 58mm...