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allis579

Briggs 300421

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allis579

I took my 300421 off of my B12 and tookit apart to determine why the points rod didn't open my points. The rod is mushroomed on the end and will not pull out and it does move about .0010. The flat on the cam appears to be ok. can't tell if the cam has a groove orn into it. That is the only thing I can tink can cause the movement to decrease.

Any ideas on how to repair this? I assume that the cam shaft iis too hard to try yo file the flat deeper. Thank you

Bob

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DanD

If the plunger rod is mushroomed, I would probably just replace it. May be a good time to replace the bushing as well if it's worn at all. Also be sure to replace the rubber seal around the plunger to help keep oil out of the points housing.

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powerking_one

Bob,

Quote:

"I took my 300421 off of my B12 and tookit apart to determine why the points rod didn't open my points. The rod is mushroomed on the end."

Briggs (for whatever design reasoning) made the points pushrod intentionally with a larger diameter "foot" at the cam lobe end than the pushrod diameter. Thus it cannot slide it out of the brass guide (outside/points side). You have to remove the guide or remove the camshaft to get it out. I would doubt it is a problem with the pushrod. Others have seen problems with the cam points lobe wearing and causing ignition & timing issues and having to compensate with taking the point's gap out of spec for it to run right.

Tom (PK)

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huffy
quote:Briggs (for whatever design reasoning) made the points pushrod intentionally with a larger diameter "foot" at the cam lobe end than the pushrod diameter. Thus it cannot slide it out of the brass guide (outside/points side). You have to remove the guide or remove the camshaft to get it out.id="quote">
id="quote">

removing the guide is not hard to do. Simply drop a few washers over the guide, put a nut on, and turn it with a wrench. It'll pull the guide out. Then you put in the new pushrod and guide.

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