So here's the story, a 50's Tecumseh 5hp walks into a bar...... Long story short, I had to do piston rings on it and im trying to put the cam and crank back in and lined up. I can't find the timing mark on the crank...... the cam side one is very visible, but there isn't a single blemish/imperfection/nub/indent anything crank gear side. I couldn't mark them when taking the cover off as the cam came with it unbeknownst to me until it was completely off and the cam dropped off right in front of me. I've looked this thing over a dozen times and I can't find anything resembling anything close to a timing mark. There is a little brownish speckle that wouldn't scrape off or wipe off so I tried setting it to that only to have it not want to start and backfiring through the carb...... That's my story and help would be much appreciated. I'll try to get a picture or two up soon.
Timing issues
- Thread starter Livin' La Vida
- Start date
It's definitely a 50's H50. I ran the numbers a while back and don't remember the exact year, and as i don't have the plate near me(i'll have to look for it) It's a cool little motor. It's got a 1" shaft, a boss on the side of the block for a vibratory fuel pump, cast iron liner... The crank definitely didn't have any nib or notch anywhere. I didn't know about the slanted tooth on the older engines. Learn something new everyday. Going to check it tomorrow. Thanks again. Will post the findings and hopefully a positive outcome.
Got it setup to run, wrapped the rope and spun it a couple times nothing. Rotating it around heard a little "breath". The threads for the sparkplug finally gave up the ghost. Now I understand that the sparkplug threads are not usually one for wearing out in an engine. But this guy was pulled from a rototiller sitting in a garden for 30+ years as decor. The carb was dust, the engine was siezed, the spark plug needed a breaker bar as well as the head bolts. One head bolt broke. Had to drill it out......... The piston has only a tiny little brown spot just above and forward of the sparkplug and thats it, no wear anywhere, no carbon on valves, nothing. I'd guess maybe 5 hours or less on it in it's whole life. The sparkplug marred the threads in the head. I managed to work a newer one and managed to have it seal, but doing compression/leak down tests on it has removed what little there was left to hold onto. Engine has very good compression 130psi three tests with throttle wide open. Will be doing a thread insert hopefully tomorrow. Finally found the engine plate. Model: 143-576062 Serial: 7047 04539
Actually, it's not unusual for the spark plug threads to strip. Had it happen to me also. Most shade tree guys don't make sure the plug threads don't get crossed when inserting the plug and they don't torque the plug to spec. The compression on H50 and up engines is pretty stout (as you measured), so a poorly inserted plug is going to strip the threads just vibrating around. Ebay sells big block heads--and they are cheap.