Is it the carb???
Thread Starter
Racer
Joined: Jun 2001
Posts: 422
Likes: 0
Is it the carb???
The BB runs fine for the first 30min of the drive then as it heats up it starts to stutter and backfire in WOT, Temp ranges are anywhere from 190 deg to 220 depending on traffic or long non stopping runs. Is it lean?? or is it leaning out in hotter temps?? I wish I could send this carb out to lars :confused:
Burning Brakes
Joined: Feb 2002
Posts: 752
Likes: 31
From: Melbourne Australia
Re: Is it the carb??? (71DropTop)
My 69 BB had the same problem...backfiring and missing above 3800rpm at WOT.
I had three problems...the main one was the timing was retarded due to me setting the timing at 4deg BTDC forgetting to disconnect the vacuum advance. (Yes, I'm an idiot) I rest the timing with the vaccum advance DISCONNECTED and bingo!
The second was the after-market fuel pump could not maintain pressure at WOT and 4000rpm, a Carter rebuildable pump fixed that.
The third problem was the replacement body on my carb (Rochester Q-Jet) did not have the idle air bypass holes drilled for the BB. Let me know, I can tell you more about this.
Not sure if that helps, you might have completely different problems, but I sure got mine fixed. Try the timing first!
Joe
I had three problems...the main one was the timing was retarded due to me setting the timing at 4deg BTDC forgetting to disconnect the vacuum advance. (Yes, I'm an idiot) I rest the timing with the vaccum advance DISCONNECTED and bingo!
The second was the after-market fuel pump could not maintain pressure at WOT and 4000rpm, a Carter rebuildable pump fixed that.
The third problem was the replacement body on my carb (Rochester Q-Jet) did not have the idle air bypass holes drilled for the BB. Let me know, I can tell you more about this.
Not sure if that helps, you might have completely different problems, but I sure got mine fixed. Try the timing first!
Joe
