C1 Carb backfire

[John C.]

When this happens is it because the timing needs to be advanced? Thanks for any help.

[John H.]

Re: C1 Carb backfire

John -

Could be retarded timing or an inadequate accelerator pump shot causing a temporary lean "hole" in the transition from the idle system to the main system. Under what specific conditions do you get a backfire?

[John C.]

Re: C1 Carb backfire

On a cold start

[William C.]

Re: C1 Carb backfire

Is the choke set correctly to full closed, and does the pulloff action meet the factory spec? Lean when cold will cause a backfire and the gradual control of the opening of the choke is designed to combat this. I assume you have the initial timing set to at least the factory specified advance.

[Verne Frantz]

Re: C1 Carb backfire

A pop through the carb is more a symptom of too much timing advance, rather than not enough. That applies when you're cranking the engine or stabbing it from an idle.