Tecumseh HM80 15521X,Family 4TPXS3182BA,DOM 04302CB0041. This engine powers a MacKissic self Propelled Vacuum-Chipper Shredder. It has pulleys on both the crank shaft and the camshaft. The engine starts easily on full choke and runs with sufficient power. It smokes and uses oil. The compression tester says 67psi but I don't know if it has an automatic compression release. It pulls through very easily and feels like it has little compression. The shredder wheel is a large heavy welded assembly bolted directly to the crank. If I turn that by hand the engine feels like it has no compression! It hot starts only under full choke but does so on the first pull as it does when it is cold.When you shut it down it keeps turning over for several revolutions due to inertia and what i feel is a lack of compression. I am going to rebuild this winter as the duel pulley block is impossible to find and the replacement Briggs that MacKissic uses now is only 6hp and a small fortune.
OK-Thats' my tale of woe! Now some questions-
1)Am I correct in assuming the crank is ok as the engine has never seized?
2)How do you check if the valve guides are ok? Can they be replaced if they are worn? The last time I rebuilt an engine I just cleaned up the carbon and reused the old valves after hand lapping them. I didn't pay any attention to the guides because I didn't know better. I got lucky as it worked but am concerned this time.(Ignorance is bliss).
3)I have a new set of stock oem valves. Should I use them?
4) New piston,rod and wrist pin are available from Stens or OEM if I hunt around. Are the Stens parts acceptable?
I hesitate to say money is not an issue because it always is but this a VERY important machine to me! I am resigned to spending some money. I went to many of the local shops thinking I would have them perform the rebuild but after discussing it with them I have no confidence in their abilities or desire to do the work.
All advice,answers to my above questions and tips will be greatly appreciated. If anybody knows of a reputable COMPETENT rebuilder on Long Island New York please let me know.
Thanks,
Marc