re: 60 MPH...achieveable? Who cares?!? Let blueprint an engine!
Now we'll start to get down to the nuts and bolts of this!
DV and I have been playing around with a customers' bike for the past 10 days just to see what we could get out of it without doing anything major.
We bolted on an intake, and a new cylinder head. We also port matched the muffler to the jug. 93 Octane fuel mixed 4 ounces to the gallon with generic air cooled 2-cycle oil. A few runs to read, and adjust the plug heat range due to the high comp head, and that's it...nothing more.
We're done experimenting with this bike...it was returned to the customer today. I could have kept it for another week to do more mods, but it was pointless. 43mph is already WAY too fast for this bike!
We disassembled a new engine today and went to the Granite inspection plate with the crank and the cases. The crank was typical: .008" out of true concentric. The bolt-on weights are never true to the crank centerline on these engines. It is one of the few that I have seen where the bearing journals are dead on...3 tenths! Impressive for sure!
The mating surfaces for the two case halves were out of square to the crank bearings by .0035". We squared-up the case surfaces on the mill. The original case register was milled away...we will be dowel pinning the cases to ensure crank to bearing alignment and prevent the cases from shuffling.
Prepping any engine is extremely tedious...there is no such thing as "good enough"! Patience and experience are the key to making any engine run to it's full potential...there are no short-cuts, no magic...just hours of work!
I should be nearly done with the engine by the time the bike gets here.
Yes...the CNC is running production on motor mounts and sprocket adapters while I'm messin' with this project.