| RG/NJ | -- 05-14-2011 @ 5:34 AM |
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I put a rebuilt 91-99 on my engine. Holding the gas pedal at a steady 1000 rpm the rpm's will go up a little and back down again. What would cause this? I also have a rebuilt model 59 i have been running on this engine and it runs absolutely perfect. Thank You
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| supereal | -- 05-14-2011 @ 7:38 AM |
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In most cases, it is caused by a vacuum leak somewhere in the intake system. As your engine runs well with a different carb I suspect two causes. The power valve may be leaking or incorrect, and the throttle shaft bushings may be worn and admitting air.the best diagnostic tool for your problem is a vacuum gauge. It will help you rule out other possibilities. If you don't have a chart, I'll post one. Finding carb problems takes a lot of time when you have it in front of you. At this distance, it is mostly guesswork.
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| supereal | -- 05-14-2011 @ 7:38 AM |
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In most cases, it is caused by a vacuum leak somewhere in the intake system. As your engine runs well with a different carb, I suspect two causes. The power valve may be leaking or incorrect, and the throttle shaft bushings may be worn and admitting air. If the power valve has been overtightened, and the gasket distorted, this may be the cause. The best diagnostic tool for your problem is a vacuum gauge. It will help you rule out other possibilities. If you don't have a chart, I'll post one. Finding carb problems takes a lot of time, even when you have it in front of you. At this distance, it is mostly guesswork, but at least you have narrowed down the possibilities. I've seen too many "rebuilt" carbs that gave trouble. This message was edited by supereal on 5-14-11 @ 2:21 PM
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| 37RAGTOPMAN | -- 05-14-2011 @ 4:55 PM |
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was wondering if you looked down the venturi[ USING A MIRROR while the engine is at 1000rpm and problem is present ] to see if you saw anyhing out of the ordinary. gas dripping or something loose or not aligned ? float level set correct, vacuumn port in carb not clogged, no restrictions by the needle and seat ? it probably is something the rebuilder overlooked, At 1000 rpm what does the vacuumn gauge do? needle steady ? my 3 cents 37RAGTOPMAN This message was edited by 37RAGTOPMAN on 5-14-11 @ 5:37 PM
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