Idle Mix cylinders Different

[1795]

I was having a problem with #8 not pulling anything and the idle screw having no effect. Took the carb apart, cleaned everything and it still was there. Talked to Jim a couple of times and as we took the carb apart again and looked at the jets my engine builder decided to run a wire up the idle jet holders (100's) and the wire ran all the way u to the base of the screw on #7 and only halfway up on #8. Called Jim and he said that it could be plugged with solder and to run a drill bit up it. Sure enough, some silver solder came out. The solder was blocking the air hole at the top of the idle jet holder. Not quite sure why it was there. It looks like there had been two holes on the idle jet holder and one had been soldered shut. Both idle jet holders were the same. Ordered a couple replacements from Pierce Manifold just in case and those idle jet holders only had one hole with no evidence of a second hole. The one hole that was there was in the same position as the filled hole on the ones in my carbs.

Re-installed everything and reset the idles screw, which was way out of line with the others, and everything worked fine. RPM's rose as I set that idle screw correctly and the engine runs consistent. Something to consider.

Jim

[65arboc]

Hi Jim,

Thanks for the update on your problem. I also run a 289 but not set up for racing. I have been chasing some similar problems with my set-up and have most things sorted out except very rich idle which I must keep set rich to avoid back fire on let-off and it helps the common hesitate at 2500-3000 rpm. I have found Jay at Pegasus has been very helpful even tho they are primarily VW tuners.
Thanks again,

Jim in Pa