[SEL] 8 cycling Witte

[John Hall]

I'm working on a 3hp model K Witte that I just can't get to run to suit me. The engine cranks when cold with 2-4 turns of the flywheels. Hot, it cranks with 1-2. I have checked exhaust timing and have it set to close just past TDC, aprox 5deg. I have also checked spark timing and it is set around 45deg BTDC (got this value out of book for an earlier Witte). The engine has great compression. It has new rings and valve springs.

With all this it seems to want to continually 8 cycle, even under load. I talked with a fellow SEL member and we were thinking air leaks around the carb. I have inspected the throttle shaft for excess wear and checked the butterfly to see if it is sealing well, both seem OK.  The fit where the carb slips into the head seems a little loose bit I tried spraying penetrating oil around it with the engine running to see if it would pull it in but I didn't notice any change. I have tried running the engine of both sides of the carbs with the same results.

I'm suspecting the choke plate. I have tried different springs as well as installed a new plate. 

Any idea what is going on here?

I tried looking for 8 cycling in the archives but something with the ATIS site wasn't working. I'd be interested to know if this topic has been well discussed in the past.

John Hall
jthall at worldnet.att.net