backfire

[eddiezuskin]

I ran into an old friend out on the water today. He has a restored 1927 wooden 38' Edwards Boat Yard Bay Boat. These are the watermans boats but this one has a small cabin with berths and a head and a huge deck area.

Symptom- Backfire over 3000rpm on 5.7 GM motor with quadrajet rebuilt carb and points ignition. Starts and runs fine until he approaches 3000rpms. I suggested he take a good look at the distributor. Worn, wobbly shaft/dwell angle problem?

Suggestions?

Eddie

 

[kbsunlovers]

May seem a bit rudimentary, but are all the plug wires correct?

 

[fc3]

First replace the plug wires, cap and rotor to ensure there is no cross-firing. Then test. If the problem continues, check the timing, distributor, and distributor advance mechanism. If that's OK, check the valve timing and timing chain.

Best regards,
Frank

 

[eddiezuskin]

Thanks for the replies. As a result of the groups suggestions my friend tells me he asked his mechanic if it was a distributor/timing problem so his mechanic pulled the cap and found the points were not adjusted correctly. Seems to have solved the problem for now.
Eddie

 

[Y Knot]

check the timing....