Re: 50cc BGF motor won't rev
Pablo ran into a problem kind of like yours his engine would start and idle but would not rev up. If you played with the choke while riding the bike you might be able to get it to rev but it was a real pain just to do.
Pablo sent me the carb and I found that what he told me about how the carb was acting to be true so I started to go over the carb. I found that all I needed to do to get it to work right was change out the needle and slide from my carb to his and it would work so I measured his needle and mine and found that his needle was not tapered correctly I tapered his needle and tried it on my bike and it worked great so I shipped his carb back to him end of story. I don't know if this is correct or not but I think his needle measured 0.070 at the top by the clip grooves and 0.070 at the bottom so there was no taper. It should be around 0.070 at the top and taper to 0.068 at the bottom but I'm not sure of the 0.068 measurement and can't check it until I return back to Texas. so if you have a way to measure your needle this is where I start looking for your problem of not reving. If you find that the needle is not tapered be very careful if you try to taper it as very small changes will affect it big time.