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8n wont rev up +

mike vann re my post march 30 on high idle. Got that fixed. Today is first day could take tractor out and run with brush mower. Now the engine runs about half throttle and wont rev up. Pull the throttle back all the way doe s do nothing runs flat. any suggestion s on what to check? The throttle lever is wide open and pulled by hand to make sure it was open all the way and it was.
Jim Loveridge You mentioned in your March 30th post that the exhaust burned your eyes. I wonder if you have bad gas. You might try draining the tank and then put fresh gas in. Other than that, it could be a weak spark. I would check for a good strong spark at the plugs. Open the gap on a plug or an old one if you have one, to 1/4 inch. You should get a nice blue ark across that gap. Timing might be retarded or the centrifugal advance isn't working.
Bob G Do you have the correct rod going to the carb from the governor?
mikevann the tractor ran good till last August. When I had problems with rusty gas tank. Changed the tank had carb rebuilt there was lots of gunk in it. Then the problems started with the strong fumes and high idle problem. When I took carb and put back on it idled fine and no burning of the eyes when running. Just doesn't rev up now. What is the centrifugal advance? none of the rods were changed. How do you check the centrifugal advance?
Bob G Don't know if your 50 is a front dist or a side mount one. On a side mount the easy way to check the mechanical advance is with a timing light.
mikevann side mount dist. How do you check it with timing light?
Bob G You remove the teardrop shaped cover from right side of bell housing and hook up timing light to number one plug wire and when running shine light in the hole and look for the timing marks. If the advance is working the timing marks will move depending on RPM.

With it running , will it increase in RPM if you reach behind carb and move the trottle plate with your fingers?

Jim Loveridge Thinking about the history since last August, I would have to think that you still have a problem inside the carburetor. I would take it completely apart and clean out all the passages with an aerosol carb. cleaner. Run wire or fishing line through all the passages too and if you have a compressor, blow them out.
mikevann Went out this am checked spark spark good. checked air cleaner ok but cleaned anyway.Checked fuel flow wasn't the greatest. cleaned all 3 screens. opened fuel on sediment bowl was looking at carb noticed gas dripping about every 15 seconds. Was dripping off small brass screw on the bottom of the carb bowl. Tighten it up about 2 1/2 - 3 turns started it up and it reved up real good. Took out side with brush mower and ran great. Only thing I could think of was sucking air. But is running good now thanks. Hope keeps going that way!
Bob g You may have fixed it when you cleaned screens!
Good luck

Jim Loveridge Great News! Thanks for letting us know. So often, we never hear back from folks.

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