w-4 with knock, need suggestions

homebuilt · Apr 11, 2010

i got my carb rebuilt and new manifold bolted up. distributar tuned up along with new wire's and spark plugs. tractor started right up but has a knock, i guess i didn't notice it when i bought the tractor due to it running quite rough. it runs nice and smooth now except for the knock. i let it get warmed up and took a lap around the yard, once warm the knock went away. i let it set overnight and this morning when i started it the knock is back. i started unplugging the wires and when i disconnect cyl. #1 the knock goes away. i quit messing with it after that. any suggestions what it could be? rod, wrist pin, valve? i don't really want to rebuild this thing now, but if that's what it need's i guess that's what will get done. thanks.

Andrew Z · Apr 11, 2010

my thoughts would be rod bearing or wrist pin
bushings.

Andrew

36F30 · Apr 11, 2010

Yep, time to pull the pan and see what you can move. Hows the oil
pressure? Generally bad wrist pins don't bleed off pressure while
the rod bearings will. Knocks from the topside caused by valves
usually only knock a few times before they grenade something.

homebuilt · Apr 11, 2010

well looks like it's time for a overhaul. journal measured out at 2.43, but they're not all torn up. look like original std size bearing's. i can easily move the piston up and down inside the sleeve. matter of fact it will slide down the cylinder under it's own weight, if left for a few seconds.

w-4 with knock, need suggestions

homebuilt

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Andrew Z

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