Hi All,

Thought I'd try here before I haul the bike to the shop and spend $$$.... Here's the deal:

Joe crashed, broke himself, not the bike. But the bike sat for about 4 months before anyone tried to start it again and now it won't start. The boys checked/cleaned the carb, checked/cleaned air filter, checked/tightened spark plug & wire. It's getting a little spark and plenty of fuel. Won't bump start. Any ideas what to check next? Any ignition parts that would go bad from just sitting? It's wierd (and frustrating!).

Help!

i worry aobut that happening with my bike its already sat 3 months since i got hurt and i have another 3 months. i made sure to clean the carb before i put it away though

Sitting around shouldn't effect any ignition parts unless something was actually damaged in the impact of the crash but that is unlikely.

When they checked the plug did they put in a new one? Make sure it is getting consistent spark and not just every now and then. I worked on a YZ400 one time that would just spark irregularly every so often and only give a pop once in a while when trying to start it.... turned out to be a sheared flywheel key so it was a $1 fix but a strange problem to figure out.

Bad Gas?
Chipped reed?
Spark plug lead loose at coil?
Air leak?

There is nothing on that bike that cant be fixed at home with basic tools except the crank and suspention.

We have checked all of those things. Spark plug lead is the most likely candidate, but you can't just replace the lead (it comes attached to the coil) so it's $80 bucks just to see if that's the problem... Ugh.

Napalm - what's a flywheel key?

I'm surprised nobody told you to keep the grips and park a Honda under it

Can you define "little spark".

Is the exhaust possibly plugged?

The flywheel key is what locks the flywheel to the crankshaft at the correct position so all the magnets line up with the coils and produce current for the spark.

It's very rare but if the key shears off then the flywheel can move around on the crank and it will cause you to have a irregular spark every so often when trying to start the bike. It may pop once if the spark happened to be timed right but it will never start. You can tell by taking the ignition cover off and trying to spin the flywheel. If the flywheel moves and the crank doesn't then it's broken.

Also you can usually unscrew the plug cap from the wire and try a spark test with the end of the wire (be careful) to see if the plug cap is the problem.

Sometime the plug wire unscrews from the coil side just like the cap unscrews from the wire. If the wire comes off you could test the wire with a multi meter. Or just find someone with a YZ125 that will let you borrow their coil for a minute.

Air
Fuel
Spark
Its one of those.
No offence Napalm, But the crank key is probly the last place to look on a 125.

Im in Lake Stevens if you want to bring it over for A look.

YZ125 help? I have all the info you need Val. Did you get it running good?

quote:

Originally posted by Big Eric:
Air
Fuel
Spark
Its one of those.
No offence Napalm, But the crank key is probly the last place to look on a 125.

Im in Lake Stevens if you want to bring it over for A look.

I know, I've only seen it once.... the bike had been to 2 shops and no one could get it running. After they guy bought a new coil at shop #1 and a new CDI at shop #2 it turned out to be the flywheel key and I got it running for like a buck, he was pissed.

Aint that how it goes sometimes.

How about water in the pipe.

Setting for a while. How about gummed up rings, weak spark, weak compression and flooded.

Could happen

If he crashed the last time it was rode...... what about dirt in the hill switch, holding it on? Or maybe just loose/unplugged wires somewhere. Or........ ground wire coming loose.

You all are great, thanks for the responses. Been too busy to mess with it, but we're going to dig into it again this weekend. If all else fails we'll get it to one of the Erics