Posted by Alan Bowes on March 05, 1999 at 14:48:11:
In Reply to: Re: Poor acceleration posted by Alan Bowes on March 05, 1999 at 10:54:37:
I was just thinking...
If you've had the engine apart for a while, it's possible that the leather skirt/seal of the accelerator pump piston has hardened up and shrunk. This can cause a lot of leakage around the piston and a flat spot when you step on the gas. After a while, they generally soften up and start sealing well again, but NOT always. As I mentioned, the spark advance is a possible problem area. If the advance weights have been messed with, or if they're sticking, it could prevent proper spark advance with engine speed increase. Also, if you've had the carb off for a while, as the fuel dries up inside the carb, bits of dried residue can come loose and clog things like the tiny orifices in the air bleed tube. One of these orifices is about the size of a human hair, and most people don't even see it when they overhaul a carb!
Have fun,
Alan Bowes