1969 Bus - Backfire

skin daddio · Post by **skin daddio** » Thu Jul 12, 2007 9:20 pm

I was not pleased with my carb since I left sf last January. Nevertheless, today I took out the '69 bus and drove for a tank of gas and was still disappointed. This evening I swapped out the carb and dizzy set from my running-well '68 dc and installed them into my '69. Everything looks ok, but it won't turn over. Instead I get a large backfire. Anybody?

dingo · Post by **dingo** » Thu Jul 12, 2007 9:53 pm

My first guess: the timing is way off. Set it cold to TDC or take a strobe to #1 and see where she lays.

Post by **Amskeptic** » Thu Jul 12, 2007 10:02 pm

skin daddio wrote:I was not pleased with my carb since I left sf last January. Nevertheless, today I took out the '69 bus and drove for a tank of gas and was still disappointed. This evening I swapped out the carb and dizzy set from my running-well '68 dc and installed them into my '69. Everything looks ok, but it won't turn over. Instead I get a large backfire. Anybody?

I assume that it is turning over (starter) but not catching (running by itself).

Like dingo sez, check timing carefully. Make sure #1 valves both have clearance at TDC and make the rotor point to #1 spark plug wire.
Colin

skin daddio · Post by **skin daddio** » Thu Jul 12, 2007 10:21 pm

Drive gear = 180 wrong degrees. oooph. I moved the wires and got it to turn over. I am putting time aside to find [remember] how to tune the 30/31, should be spot on when that is done. [edit http://www.type-14.com/engine.htm] Dwell is fine, ignition happy. At this point, it prolly needs the air mix polished, and more test drives. Thanks fellas.

Itinerant Air-Cooled

Itinerant Air-Cooled

1969 Bus - Backfire

1969 Bus - Backfire

Re: 1969 Bus - Backfire