The original buyer bought and installed this engine but never could get it running and finally damaged the top end trying.
In frustration, he sent it back and I ended up installing a complete new top end and giving it a general check out.
Since there had been issues, the customer asked me to test fire it before shipping it back, which I attempted to do by installing it on My Pig, but with no luck.
The engine had a nice, fat blue spark, plenty of air and fuel but would not even pop once. I pedaled it until I was puffing like a hippie at a NORML festival.
Then I remembered a post I saw here awhile back and decided to try one more thing before giving up in disgust.
Turned out to be a very simple problem to fix, yet insanely difficult to think of without having heard of the issue.
This is why this engine never wanted to run:
Notice the difference in position between the installed magnet and the one I'm holding up? The keyway was cut wrong.
The magnet was improperly timed due to this simple mistake in manufacturing. The engine was getting a great spark, but at the wrong time. No way was it ever going to run with this part installed.
This is the PROPER ORIENTATION of the magnet when the engine is at TDC
These magnets should be removed and discarded when found.
Notice where the keyway is in relation to the armature.
In the CORRECT magnet, the keyway would be noticeably closer to 9:30 than the 9 o'clock shown on this INCORRECT magnet.
Unless you know to check for this, it can cause diagnosis nightmares and foul language.
Remember, this keyway can be off and the engine still run, only run very poorly. So when you run across one that seems haunted or depressed, check that timing!
In frustration, he sent it back and I ended up installing a complete new top end and giving it a general check out.
Since there had been issues, the customer asked me to test fire it before shipping it back, which I attempted to do by installing it on My Pig, but with no luck.
The engine had a nice, fat blue spark, plenty of air and fuel but would not even pop once. I pedaled it until I was puffing like a hippie at a NORML festival.
Then I remembered a post I saw here awhile back and decided to try one more thing before giving up in disgust.
Turned out to be a very simple problem to fix, yet insanely difficult to think of without having heard of the issue.
This is why this engine never wanted to run:
Notice the difference in position between the installed magnet and the one I'm holding up? The keyway was cut wrong.
The magnet was improperly timed due to this simple mistake in manufacturing. The engine was getting a great spark, but at the wrong time. No way was it ever going to run with this part installed.
This is the PROPER ORIENTATION of the magnet when the engine is at TDC
These magnets should be removed and discarded when found.
Notice where the keyway is in relation to the armature.
In the CORRECT magnet, the keyway would be noticeably closer to 9:30 than the 9 o'clock shown on this INCORRECT magnet.
Unless you know to check for this, it can cause diagnosis nightmares and foul language.
Remember, this keyway can be off and the engine still run, only run very poorly. So when you run across one that seems haunted or depressed, check that timing!
