So, I recently got my moped ('77 Batavus VA) out of the shop. I had someone else set the timing, after I installed new points, (oh, and my ignition coil was bad, but I had that weird integrated ignition, so I had to replace that with the regular setup, if you know what I'm talking about, good, if you don't, it doesn't matter). Before it broke down, it would top out at around 35 mph, but after I got it fixed, now it maxes at about 20-25mph.
It's weird, it won't climb in rpm's after about 20mph, it just stays at this really low rpm. It won't "open up" even at full throttle. like it has a governor in it, which I know it doesn't.
I know that my moped came in 3 different versions: a 20, 25, and 30mph. The only difference I've been able to find anywhere between the versions is the carb jet size. My jet size is, and has always been, a 52. It ran up to 35mph on a 52 jet; but the 52 jet is the jet that the manual says was put on the 20mph version, so I'm thinking that my 'ped was intended to be a 20mph, and the only real change has been setting the timing with the new points, so I'm thinking that the previous owner set the timing advanced from the stock 2mm btdc to give it a little extra kick. Now the timing is at stock, and it's running slower. I just figured originally that they put a smaller jet in because I'm up at 5280ft here in denver, and the air is pretty thin, so to compensate they put in a smaller jet, but now I'm thinking otherwise. Tonight I taped off half of the air filter, to try to make it run a little richer (a friend of mine had amazing results with a similar experiment) but that just made it run even slower, so I took the tape off. I'm not willing to advance the timing, as i want my 'ped to last as long as it can. Does anyone have any ideas? Tonight I'm going to order a few different sized jets (both smaller and larger than 52) and see if they make any difference.
Any help would be very appreciated. Thanks.