sinteger

when i spray carb cleaner on the front side and around the engine side of the base of the carb it idles up. i suppose this indicates a leak somewhere, but i cant find it. i have a block plate on the intake where the egr pipe went, and the egr is completely gone and blocked off. i took the adapter plates off a couple days ago and applied a thin coat of blue rtv, but the same leak/s still seem to be present. when i look into the primary side of the carb at idle, you can see fuel dumping in, i hear this is not kosher... but i cant seem to figure that out either, i tried lowering the float and checked the needle valve for functionality, seems fine, but lowering the float changed nothing either. the intake manifold gasket, if leaking, couldnt cause this could it?

xxxtreme22r

sounds like the carb base gasket(s) is(are) leaking.

sinteger

so i investigated further... and behold i have found the leak. it appears the base of the carb is warped (again its used) and leaks right at the front side in the center. you can even see the spot by spraying with carb cleaner and if you watch the edge of the gasket, the spot where the leak is dries out very fast. i have seen this before with other things, and im going to try filing the base to level it out tomorrow. my theory at this point is the leak is causing the mixture screw to do nothing, and causing the carb to dump more fuel as though the throttle is open. if i put my hand over the carb and restrict air flow, she idles up very nicely, and holding this i can turn my idle screw back out to where it barely touches the linkage. then when i remove my hand it dies.

edit: i also imagine since its dumping fuel like that its causing the dieseling and makes the idle jet basically inconsequential, explaining why the idle cut solenoid seems to have no effect.

sinteger

I took the carb off and put a piece of glass across the bottom, and boy was she warped. i filed the base down and achieved a much more level surface than i started with. i cant find a leak around the carb itself anymore but it's definitely still leaking and it seems like its more on the back side.

i'm using the "cheap" redline adapter kit... from some reading i've done they "never want to seal right" so i'm thinking about buying the "pro spiral" adapter from LCE. think this is a worthwhile investment?

also i installed the carter 4070 fuel pump with no regulator and it seems to do just fine, but it did not fix the issue where it stalls on braking. is it probable that it too is being caused by the base of the carb leaking?

xxxtreme22r

I considered that adapter from LCE as well. there are other 1 piece adapters as well. I have the two piece myself. I don't know of anyone on here or any of the other forums that are running the LCE adapter, but seem like a good idea.

and get a regulator on that carb.

JonnyBoy

The LCE adapter is still a 2 piece, just much better quality as it's machined aluminum instead of cast like the adapter provided in the kits.

sinteger

i have not replaced the adapter kit yet, but i believe now that the leak(s) are the throttle shaft bushings. i bought this carb used so who knows how much mileage is on it. does anyone feel that a vacuum leak around those bushings can cause it to run THAT bad? should i dish out $20/shaft for the bearing kit to replace the bushings? or just go with the $7/shaft bushings?

jlm9186

Just a little warning. Watch your oil level if you can hear fuel goin in there is a chance of it workin down to the oil pan and causing it idle and stall. Had this problem a while back. Check that oil level