I'm working on my son's Maxi to get it to a super quick but not too much top speed bike. At the moment it has a TCCD 50cc, 14mm Bing, Metal Mesh Filter, a Estoril Side Bleed and 15/36 gearing on it. Got it close on the tuning the other day and it clocked 43mph on a relatively flat road.
I rebuilt the engine but used the original crank, only 1000 miles on it, probably should have changed it out while I was in there, oh well...
The gear chart says that 43mph is 8000rpms. I'd really like to keep him around 35mph, which would mean changing out one of the gears to match the chart, say a 13/36 which would give 37mph at 8000rpms.
So my question is, does changing the gearing out run the risk of over revving the engine? Would my top rmp of 8000 go up because of the new gearing? Or is the top rpm regulated more by the cylinder/carb/intake/exhaust combo?