the 400 - one more time

rosedale123 · Oct 7, 2015

This is the one that had the miss. Adjusted the timing with a timing light and she ran like a top ; ran great for hours of mowing. But then...... the miss has come back. I will check the timing and check to see if it has moved . If it has moved ( the timing) , does it sound like there is something something worn in the dizzy? I have read about the "bushing" but not sure where that is and how to fix - could that be it? Any and all help is appreciated by my Dad and I. I hope the next time I post I can tell you the "fix".... with your help.

Thank you!

gene bender · Oct 7, 2015

Easy way to check is hook your timing lite starting with #1 watch the flashes should not mis a beat then go to #2 watch again if all four have steady fire your bushing is probably good

CenTex Farmall · Oct 7, 2015

Sometimes the gear on the hydraulic pump can become a little bit loose and start working back and forth. The result is a worn keyway and key and timing that can change at will. Have had two apart this year like that.

The gear on the distributor has a pin that holds it on. That could possibly be loose. Also the teeth on the distributor gear or the intermediate shaft could be worn. You may be able to feel play by hand turning the rotor end back and forth, keeping in mind an allowance for movement of the mechanical advance.

Janicholson · Oct 7, 2015

I will ad that at the moment of flash, the pulley should be very consistent in location. if the flashed location jumps forward and back, that is also an indication of bushing failure. (note, the light will flash on, or near, the timing marks only on #1) Jim

Andy Martin · Oct 9, 2015

Is the cam in the distributor greased lightly? You could be wearing the cam follower down on the points, causing them to not open as wide and changing the timing and dwell.

used red MN · Oct 9, 2015

Just to add for giggles with apologies to Jim....it will also flash "on or near the timing mark on number 4 cyl because it fires exactly one turn of the crank behind cyl number one. (Firing order 1342 -4 cycle engine) If this needs more explanation just ask and I'll add a more detailed explanation.

the 400 - one more time

rosedale123

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gene bender

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CenTex Farmall

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Janicholson

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Andy Martin

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used red MN

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