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Discussion Starter #1
So after spending a few months going over my SS12, I finally got to use it. After about an hour of mowing, I hear a knock from the engine. The knock lasted just long enough for me to think "maybe I should shut that down" and then CRACK! Took the side cover off of the engine, and found this. :banghead3
engine side:

cover side:

Total damages: Camshaft (obviously) shot, govenor is missing teeth, and the teeth on the crankshaft are spalled up. Dunno if I can clean them up enough to make them useable or not. I still have to figure out if there was an underlying cause for the damage, or if the camshaft was just fatigued from years of use and finaly gave out. Before this happened, I did have the head trued up, so the engine did have more compression, though I doubt that had anything to do with it. Time to hit up CL and Ebay to find either some parts or another HH120 to swap in.
 

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rscurtis

Looks like the rod is all there.

Exto

I have the parts you need, if you are going to fix it. Used govener gear and cam shaft.
 

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Discussion Starter #4
Rscurtis, yup the connecting rod is all there, that's just the oil splasher rod on the bottom of the connecting rod. SmallFry, pm sent about those parts.
 

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:eek:...never seen a cam break like that before,on any engine...looks like it snapped where the compression release pin passes through the journals!..maybe the compression release pin got caught on the lifter and it tore it out ,snapping the cam in the process..

I always dread my HH120's having a catastrophic failure like this,after all,they are 40+ years old and have undoubtedly had a rough life before I got hold of them!..seeing these engines aren't exactly plentiful or cheap for parts,I would probably be forced to do an engine swap if one of mine should grenade..

I guess having a hevy duty forged connecting rod,timken bearings and a sodium stellite exhaust valve dont help your engine last if the cam snaps in half,huh??..:(
 

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Discussion Starter #6
Nope not so much. I was kinda shocked that it grenaded like that too, of all the things that could snap, that was low on my list. I'm kinda wondering if there were fatigue cracks in the crank right at that pin already. I thought that bringing in parts for a 12 horse enging to be magnafluxed seemed a bit exessive, so I guess I'll never know. My other suspect is a seized valve, though it seems unlikely. The valves guides and shafts looked good when I pulled the engine apart the first time, and I just topped off the engine with oil before I ran it. And before someone asks, yes the valve timing was correct.
 

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Discussion Starter #7
:banghead3

Ok, so another member was nice enough to sell me the parts I needed to rebuild my engine. Unfortunately, I kinda goofed, and forgot to check if his engine had points or solid state ignition. oops. The camshaft will fit perfectly in the engine, but it won't play nice with my ignition setup. I'll either have to get the bearing surface for the points cam machined down and the attachment points for the timing retard hooked up, or fine someone that happens to have the correct cam. (The cams are cut from the same blank, the points style just has extra machining done for the extra bits and pieces.)
Or else I suppose I can convert my machine over to solid state ignition. I'd need to pick up the electronics, and maybe a new flywheel. I don't know the exact differences between the two systems, so I don't know what all I'd have to change over. Any help?
 

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Discussion Starter #9
I'll keep it. It will probably be easier (and less expensive in the long run) to change over to the solid state ignition.
 

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I'd keep it points if it were me..I'm not a huge fan of the solid state ignition,especially if and when it decides to crap out on you..its costly and complicated to replace, or build another suitable substitute for it..Why Tecumseh couldn't have left the cam & block set up for points AND solid state ignition I dont know,other than to make life suck for us !..
 

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Ok if you change your mind let me know. The solid state works great, maintance free and last 35 or 40 years, but it is costly. Points you have to clean or change once in a while but are easy to fix and cheap to buy.

I think I would try to find the points cam and keep the points. I guess it would depend on how much has to be changed and how much it's going to cost.
 

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Discussion Starter #12 (Edited)
I'd keep it points if it were me..I'm not a huge fan of the solid state ignition,especially if and when it decides to crap out on you..its costly and complicated to replace, or build another suitable substitute for it..Why Tecumseh couldn't have left the cam & block set up for points AND solid state ignition I dont know,other than to make life suck for us !..
Actually, the solid state cam is cut from the same blank as the points cam (at least the one I got from Small Fry is) The points ignition setup just has some additional parts and machining involved. I could have the unit I have here machined to work, I just don't want to spend the money.

I found an ignition setup for a smaller tecumseh engine (self contained unit, picks up from the outside of the flywheel) I was thinking about seeing if it will work.
 
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