piston porting, widening ports

[Fabian]

If the engine is assembled, you need to lubricate the crankshaft and the seals, then carefully press them over the shaft and drive them home approx 0.5mm below the outside face of the engine case.

 

[HeadSmess]

then carefully press them over the shaft and drive them home approx 0.5mm below the outside face of the engine case.

using a socket ideally. small plug sockets about the right size.

 

[Fabian]

using a socket ideally. small plug sockets about the right size.

but preferably have someone turn up a piece of plastic with a centre hole that fits snugly over the crankshaft, and with a centre section that is machined 0.5mm proud of the the larger outside diameter, to press the crankshaft seals into place; ensuring they sit in place perfectly true and with consistent recess.

I have had a tube socket/plug socket leave scratch marks/dent marks in the crankshaft, so this method is no longer used in my assembly process.

 

[Fast Shag]

I was able to get everything back together...Seal went on really nice and even, all lubed up. HD Lighting hooked up, new mag...She fired right up and the low end was insane! Much better throttle response, top end pulled 2mph faster. Hill climbing gave me 2.5mph better as well. By widening ports, I could tell a slight increase in RPM. Very impressed with this!

ported piston at transfers and exhaust, sharpened transfer points at crankcase, widened intake and exhaust ports by 2mm each. New crankcase seal on mag side, new mag, new CDI. STOKED!