Trouble shooting the bicycle engine that won't start

bravofire84 · #11 (**permalink**) 02-22-2008, 06:07 PM

i know when i got my kit the cdi wire jus luckily happened to be connected to the unit but i connectedit and got spark. Jus sayin check the obvious i was lucky it could be fixed.

deacon · #12 (**permalink**) 02-22-2008, 06:15 PM

Mine fell out after a few miles so yeah check everything easy first. Always my first rule of repair. Save the hard stuff till everything else has be ruled out.

dgoria5 · #13 (**permalink**) 03-18-2008, 08:36 PM

after having fuel problems and wouldn't start so i disassembled the carb and put it back together. However now when i go to start it nothing happens at all, the wirring noise is not even present. does anyone know what this may be and how to fix it? I'm surprised that im getting so many problems out of a new motor. but hey it does'nt only happen with these chinese motors

deacon · #14 (**permalink**) 03-18-2008, 08:43 PM

I don't know if anyone else agrees but it seems to me when there is no whirring noise it is the ignition. No fire on the plug kind of thing. don't ask me why but that seems to always be the case with me. disconnect your kill switch and check the other wires. Your plug wire as well. Mine fell out once.

**Bikeguy Joe** · #15 (**permalink**) 03-19-2008, 07:50 AM

No whirring noise? Is the engine turning over, or is the clutch slipping?

When you drop the clutch, does it get really hard to pedal, but no sounds at all?
Or does it get really hard to pedal, and sound like an engine, but with no power?

dgoria5 · #16 (**permalink**) 03-21-2008, 09:44 AM

I Checked all the wiring and it seems to be fine. However when i took the spark plug out to see if there was any spark the motor did start to whirr. There was no spark. when i put the plug back in again no whirring noise. could it be a faulty plug? or is it something else llike the CDI or the magneto?

thatsdax · #17 (**permalink**) 03-21-2008, 09:48 AM

Check the magneto with a DVOM. Check between the blue and the black wire open or unplugged. Value should be around 253 ohms between those 2 wires. Thanks..

deacon · #18 (**permalink**) 03-21-2008, 05:56 PM

If you dont have a meter check to see if the wire itself will spark. It it does its the plug if not then it is likely the cdi or the magneto.

**Bikeguy Joe** · #19 (**permalink**) 03-21-2008, 05:57 PM

Quote:

Originally Posted by dgoria5

I Checked all the wiring and it seems to be fine. However when i took the spark plug out to see if there was any spark the motor did start to whirr. There was no spark. when i put the plug back in again no whirring noise. could it be a faulty plug? or is it something else llike the CDI or the magneto?

.k., no whirring noise when you put the plug back? Sounds like the clutch is slipping and not turning the engine over.

Also, you said there was no spark. Did you have the plug grounded to the engine when you spun it over?

deacon · #20 (**permalink**) 03-21-2008, 06:03 PM

Joe has a good point the added compression might mean the clutch is slipping enough to not allow the engine with compression to turn over. That makes pretty good sense. But the no compression engine will turn over since it is easier on the clutch.