The small "big block" project

[68C15]

I had a similar bike in my early teens. It was a blast until I poured in some methanol. Cruising down the sidewalk I cracked the throttle. The cylinder head blew off and imprinted the seat base with bolt heads. That's what I get for shaving the head, relieving the valves, grinding the cam, and having a machinist weld the piston into a dome shape.

[NONHOG]

Originally Posted by alsriv2

Very cool project. I had a bike like that many, many, many years ago. Did a huge upgrade from a 2.5hp Briggs to a 4hp Briggs. That thing would fly, but we had a hard time getting any parts up in Maine back then to keep it going.

Thanks! Its a knock off, but its a lot of fun. Funny how much speed parts are available for these HF 6.5 engines. Hope a tensioner is easy to find.

Originally Posted by 68C15

I had a similar bike in my early teens. It was a blast until I poured in some methanol. Cruising down the sidewalk I cracked the throttle. The cylinder head blew off and imprinted the seat base with bolt heads. That's what I get for shaving the head, relieving the valves, grinding the cam, and having a machinist weld the piston into a dome shape.

I read that removing the governor takes the rpm from 3500 to 5000 (ish)
Its also has a good probability of blowing up.

For now it stays stock except air cleaner and header. Air cleaner yet to be figured out. K&N valve cover breather?

More progress on header till I ran out of gas. (MIG)

[NONHOG]

On the previous post, I nailed it on centering the pilot drill hole. that never happens for me! Then used the step bit to get it the right size. Did some tacks to seal it up and hoping the offset hole will quiet it down a tiny bit?