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Engine flutter?

twjones114's Avatar
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04-29-03, 07:44 PM   #1  
Engine flutter?

I have two engines giving me the same problem. One is a Briggs 20.5 HP on a Craftsman mower, the other is a Tecumseh 5 hp on a wheeled string trimmer. Both units RPM seems to 'flutter' in other words it pulsates, not steady as it was.
I have cleaned gas, replace fuel filter, air filter and spark plugs to no avail, oddly enough they both seem to work better when working than sitting at idle. Any suggestions?

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mower17's Avatar

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04-29-03, 09:03 PM   #2  
It sounds like both engines are running lean. A fuel mixture adjustment is needed. Try backing the screw out 1/4 turn.

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04-30-03, 05:52 AM   #3  
I agree, but I have already set the air mixture according to Manufacturers specs, still have the problem, even runs better with choke opened a little. Could anything else be causing the problem?

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04-30-03, 09:10 AM   #4  
I agree. They sound lean. Sometimes you have to deviate from OEM a bit to get it to run right. Each machine differs from the next one due to tolerances, etc.

Have you cleaned out the fuel bowl and bolt on the 5 HP Tecumesh? That is the usual cause for problems with surging/loping.

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04-30-03, 10:25 PM   #5  
Hello TWjones!

I also agree that you are running too lean. You may need to clean the carburetors out. Especially if they had old stale gas in them. You may find water, trash, rust, etc... The small holes in the bowl screw on the tecumseh are a trouble spot, and need cleaning occasionally.

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