backfiring carb still...

[CobraSix]

Okay, I'm still only running my center carb. I'm getting occasional (like once every 15-20 minutes) backfiring from my engine. I assume it's from the carb, because it only happens under load and sounds like it is coming from the carb.

My engine currently:

idling very smooth at 750 RPM (and I mean very smooth).
15 inHG vacuum at 750 RPM
8* BTDC initial timing.

Now, I'm thinking that my advance curve may not be working properly and maybe the engine is not advancing enough at higher speeds. I just thought about that as I was typing this. I have not checked my 2500 RPM timing.

Is there anything else I should be looking for? I want to solve this problem before I hook the offy back up.

Slade

 

[xctasy]

Can't be sure, my last gasoline engine was 1994....

Excessive lean condition. The accelerator jet and fuel/air ratio will be out of kilter for your six when under load. When the other two carbs are set up, it will richen mixture during this phase. That's my thoughts. Should be happening about 1/3 rd throttle under load sometimes?

 

[Junk-Falcon]

just t

 

[CobraSix]

I do have adjustable rockers, and I do need to re-adjust them, since they haven't been re-adjusted since the engine was re-fired with the new cam, lifters, and adjustable rockers.

Slade