Originally Posted by PerryP180
I've pulled it apart except for the casing below the jug. I'm hoping to find the problem before I get to that. The rings look good. The bearing on the upper part of the connecting rod just fell apart when I slid it out of the hole. There is no scoring on the inside of the jug but there is a spot by the exhaust port about the size of a quarter where the zinc coating looks to have peeled off. It doesn't look scraped. What really worries me is that nothing I've seen so far would cause the motor to just die the way it did. Except for the rattling noise it ran great. This is leading me to think it might be the bearing for the magnet inside the magneto. I really hate to pull the magnet because it is my understanding that with that done I will have to reset the timing.
Could the bad bearing in the connecting rod have hampered the piston motion enough to kill the motor? Does anyone know if the bearing on the bottom end of the connecting rod is the same size as the upper? The upper connecting rod bearing seemed to still work it was just so worn out that the rollers fell out when pressure was removed from it.
That is a misconception. There is NO timing adjustment on "STOCK" magnetos, Although the magnet can go in backwards. To solve this problem with one already installed is place a mark on the side facing you, pull the magnet. BUT, although I have never had the occasion or inspecting the rod bearing, I doubt they are the same. Also feel (could be wrong) that the two halves of the crank are pressed together, without a press if the crankshaft bearings are bad, I think a new one would be the most cost effective.
Installing the magnet on a HT
Magnetto pictures by Ron-Becker - Photobucket
Also other things could be wrong beside the engine noise to make it die.