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What is the best way to clean the carbon out of the engine?
Is motorvac safe? I have a 1966 Pontiac Catalina. Is it better to do it through the vaccuum lines or the carburator? Took my car to a garage and they said they could not do it b/c of it having a carberator and they said they could not shut off the fuel line. I don't know if this is true or they did not want to be bothered with it.
posted: August 23, 2012
  Answers (6)
when the eng gets hot will it start or do you have to let it cool down to start it again. The best way is to run it thru alarge vacuum line, like the brake booster hose, or pcv hose. And most cleaner's you don't have to shut the fuel off. If its real bad you may have to remove the heads and use a brillow pad on a die grinder. The reason it is mostly carbouned up, is because the flange on the exhaust manafoid is shut. Some times its because there is know vacuum going to it. Or its stuck shut. check this, it should be on the rt side, were the exhaust pipe atacthes to the manafold.
posted:  August 23, 2012
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many years ago before all these fancy liquids we used to bring the rpm up to abut 1000 and dump water slowly into the carb ,you would be suprised what came out of the tailpipe.
posted:  August 24, 2012
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we used to hold a high idle and pour atf in the carb
posted:  August 24, 2012
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water will shock the carbon off. It works
posted:  August 24, 2012
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The best is using Marvel Mystery Oil, put some in oil, gas tank, and pour some down the carb while holding the throtle open a little to keep it from dying. You can tear down and look at valves and pistons after this and they will shine............
posted:  August 31, 2012
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Though my past experiences with small block chevys yearsago pour atf down the carb, at high idle keeping it running until you see white smoke coming out of the pipes, then drown the engine till it kills. Wait a couple of minute for the atf to soak in the carbon then restart the engine, take it out and run moderatly not hard until it quits smoking. Carbon knock should be gone. Works great for me every time.
posted:  November 5, 2012
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