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68gmsee · 10-26-2012, 01:50 PM

The monojet is a very easy carb to take apart and clean. Get a kit from the local auto parts and dive in. We should be able to help you if you have questions.

I have taken several of those apart and rebuilt. Buy at least 2 cans of carb cleaner. You should also replace the float if it has the black phenolic one. I've heard they get fuel logged even though I've never seen it. Check the gasket between the top half and lower half to make sure it's tight or not leaking (two phillips head screws from the bottom of the carb).

After you do that, adjust the idle speed and idle air screw for best, smoothest idle or highest vacuum. Keep resetting the idle to specs if the engine rpm goes up and recheck the adjustment.

Other things that can cause bogging, hesitation and/or backfiring are burned valves, weak valve springs, worn cam and or cam gears, bad distributor. An HEI distributor would help if that were the case.

10-26-2012, 01:50 PM	#20
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: Cracked Exhaust Manifold Questions The monojet is a very easy carb to take apart and clean. Get a kit from the local auto parts and dive in. We should be able to help you if you have questions. I have taken several of those apart and rebuilt. Buy at least 2 cans of carb cleaner. You should also replace the float if it has the black phenolic one. I've heard they get fuel logged even though I've never seen it. Check the gasket between the top half and lower half to make sure it's tight or not leaking (two phillips head screws from the bottom of the carb). After you do that, adjust the idle speed and idle air screw for best, smoothest idle or highest vacuum. Keep resetting the idle to specs if the engine rpm goes up and recheck the adjustment. Other things that can cause bogging, hesitation and/or backfiring are burned valves, weak valve springs, worn cam and or cam gears, bad distributor. An HEI distributor would help if that were the case. __________________ 68 GMC 250/3 speed Saginaw p/b p/s 69 Chevy 350/350 currently in pieces still lookin for a cab 06 Trailblazer I just want a vehicle that I can work on, that won't talk to me, leave error msgs or keep track of how I drive...