Combat Wombat running problems

[mach1970]

Hi All,

I have a combat wombat that I am trying to get back to running condition. New rings, etc, stock exhaust, everything is as it should be. Cleaned and rebuilt the stock carb. The bike does start but will only run for a few seconds and then dies. Kick it a couple times and it will start again and then die again after a couple seconds. For the couple seconds that it runs, it seems to respond well to throttle, revs nicely and then dies. Removed carb and re-cleaned again in an ultrasonic cleaner. All new stock jets from the rebuild kit I got from strictly hodaka.

Any ideas?

Thanks,
Rob

[thrownchain]

Petcock flowing enough fuel? Inline filter clean?

[thrownchain]

Float level correct?

[olddogs]

Try starting the engine with the pipe off. Mice, hornets and squirrels like to pack pipes and restrict exhaust flow.

[mach1970]

Pipe is clear, petcock is flowing enough fuel and I am not running an inline filter. I did set the float height when I rebuilt the carb.

[matt glascock]

Sure sounds like a possible fuel starvation issue. Have you removed the main jet banjo bolt when the motor dies just to see if there is indeed fuel in the float bowl? Have you confirmed that the floats, needle and seat are freely moveable? Have you looked at the spark plug and/or changed the spark plug and given the spark plug wire at least a good visual inspection for any defects in the insulation causing a fault to ground? Also, there is the possibility that there is a loose connection or frayed wire that is causing an intermittent fault in the electrical system as the engine begins to vibrate. Also, back to the carburetor, the pilot circuit features a very small passage that is quite easily blocked with varnish, dirt, etc. You might consider running a fine copper wire through the entire passageway a few times followed by a generous squirt of carb cleaner to really blast out any obstructing crud. The symptoms you describe sound pilot circuit-ish to me. If you don't have one, a great investment would be getting a copy of the official Hodaka Wombat/Combat Wombat Workshop Manual (Paul has them available on SH). Mine sits on my night stand. Therein, you will find an excellent section on maintenance and tuning of the Mikuni carburetor.

[olddogs]

OK. Still sounds like the classic carbon buildup in the pipe problem. I would still confirm by removing it.

I like to remove the carb and put a longer fuel hose on and remove the float bowl, hold the carb over a pan and visually check the flow. Moving the float up and down will verify enough is getting into the bowl. If you are positive the pipe and pilot jet are not plugged, and its getting fuel, an air leak between the manifold and cylinder or the carb and the manifold can produce the run and die condition you describe.

[matt glascock]

Oh, and get an in-line filter. Universally recommended by the pros on this forum.

[Joe Ormonde]

What I really like is when you have 2 problems at the same time. When my 71 Super Rat was 1 week old it did the same thing. It was the Secondary Coil(Under Tank). Years ago we went on Vacation and it sat for 10 days. Would not start. What was it? The Reed Petals were glued shut by the good old Castrol R that was coating the Petals! That one took me a little time to figure out. Joe Ormonde.