Engine Trouble Running Essentials- a complete troubleshooting guide

[danlandberg]

Yes, if it was installed wrong it wouldn't start at all.
The first one that went bad was 4 or 5 years ago. Had me totally stumped, did not think a magnet would loose magnetism. I didn't find any threads on it.
After replacement the thing ran fine for about 1000 to 1200 miles (Except normal ware and tare, a couple intake and exhaust gasket failures, fuel filter replacement,etc.).
Until it was stolen. (have two listed in "STOLEN BIKES") Have had a total of 4 stolen. (over the last 10 years).
This is the 2nd magnet go bad out of the five personal builds. And this is the first magnet I got that was bad already, new from GasBike.net. Luck of the draw I guess.
Or better yet, BAD luck.

 

[danlandberg]

By the way Stoneman; I think I looked like your avatar after plug, wire,
and cap, CDI, and mag coil replacement. And still no spark.
Darn non magnetized magnets anyway.

 

[Frankenstein]

Jag you really need to add the paint behind the magneto thing to the list, I've seen it 2 or 3 times before so it's gotta happen often enough to people with black painted engines...

 

[danlandberg]

Well had a couple of above freezing days last week, Was able to work in my 10' X 10' work shed/shop. I decided to test the mag and cdi forward and backward.
I also took the best magnet from one magneto mag. and put it in another magneto mag. making sure the poles (north/south) were correct. These are the readings I got.
CDI (20k setting)
Black test lead to black wire.......Red test lead to spark plug cap---6.43
Black test lead to blue wire......Red test lead to spark plug cap---no reading
Red teat lead to blue wire.....Black test lead to spark plug cap---no reading
Red test lead to black wire.....Black test lead to spark plug cap---6.44
Black test lead to black wire.....Red test lead to blue wire and vice versa---no reading (no one shows this test)
Like I said, testing forward/backward and vice versa.
MAGNETO COIL/LOOP (20k setting)
Black test lead to black wire.....Red test lead to blue wire---0.31 vice versa-----0.31
Black test lead to black wire.....Red to ground---0.000 vice versa---0.000
Black to blue wire.....Red to ground---0.31 vice versa---0.31
These tests were done with my FREE State of the Fart Harbor Freight multi meter.
I can't get an accurate AC voltage reading from the magneto with this meter. Can't keep a consistent RPM.
I still have no spark at the spark plug, but it will light up the cheap Harbor Freight spark tester (dimly).
I'm still thinking weak magnets.

 

[crassius]

I've never found a reliable way to test CDI with a meter, For most folks it is best to just try a different CDI. Much more likely a bad CDI than bad magnet.

 

[danlandberg]

I have another CDI that is 0.02 ohms different, No spark either.

 

[crassius]

to be sure it isn't two bad CDIs, try one on different bike

 

[danlandberg]

Don't have a spare. I have only seen 2 others in this town (so far) and I don't know the owners.
Iv'e had a magnet go bad before.
I found a 3/8" shank and turned the engine over with my cordless drill. Got a volt reading of 19.3-20.2 with the meter set 0n 200 ACV.
The RPMs were low with the drill.

 

[crassius]

bummer, I'm a repair shop and I've built a tester for the CDIs - not a thing the average rider would do - maybe you can find a set of spares online to use to find which is bad

 

[danlandberg]

Would you consider telling me how to build a CDI tester? I am not the average rider.