SLOWREV, you nailed it. Had bent pushrods for cylinders 1 and 3. Runs like a top now. I guess I can stop browsing the tractor sales websites for a replacement.
Thanks for the advice. This is a great resource.
Seen it happen before on that type of engine. Ususally due to the tractor sitting outside and the valves stick a bit. When you fire it up it bends pushrods.
The valves often come unstuck and are fine except for the bent pushrods.
I do recommend keeping it inside though
Ben
I really don't have any way to keep it inside. How would keeping it inside an unheated shelter prevent the valves from sticking? And what can I do as a preventative measure to protect it while it is outside?
Water down the stack causes the stuck valves and bent push rods. I know from friends experience.
A can over the exhaust and make sure the exhaust is tight where it goes into the manifold. Some stove cement will seal it up pretty good if loose/wobbly.
the exhaust flapper things help but will let some water down the pipe sometimes.
Just keep the rain from getting into the manifold, no problem on the intake since it is an updraft carb
RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
I agree with slowrev... muffler or stove or chimney putty at any mufler to manifold connection where water could go down a connector sleave.. or wick in, and then a folgers can over the stack.
Should I be putting a lead additive in the fuel? It occurred to me that this engine was more than likely designed for leaded fuel, and I believe the purpose of the lead was to lubricate the valves.
RK 55HC,ym1700, NH7610S, Ford 8N, 2N, NAA, 660, 850 x2, 541, 950, 941D, 951, 2000, 3000, 4000, 4600, 5000, 740, IH 'C' 'H', CUB, John Deere 'B', allis 'G', case VAC
NO.. tetra ethyl lead was added as an anti ping/spark knock ( octane issue ).. NOT as valve lube.
Likely your unit DOES have hardened valve seats.. check your parts catalogs. Gas in the old days was 70ish octane.. that makes for preignition and spark knock.... Modern 89/93 high octane gas is -fine- in low compression engines...