Bike cutting off

[proctorbc2005]

Strange issue with friends 04 YFZ 450.
He starts and rides it for about 2 mins, and it cuts off. It will not restart. If you let the bike sit for about an Hour, it will start run for about 2 min cut off, the entire process repeats. Bike will do the same thing if it is just left to Idle for 2 mins.

Any thought.

His bike is prety much bone stock, as far as the ignition system, and motor are concerned. He does have a Alba pipe, and K&N filter. That is about it.

[yamahahaha]

my bike did the same thing,,, but i had it jetted for a pipe but had the stock pipe on it because i was selling it, also see if ur gas is fully turned on, i had that happen to. it would only run for 2 mins about with both those things that happened

[proctorbc2005]

Forgot to mention, his carb is jetted for his pipe.

The gas being turned on was the first thing I checked. Rmoved hose from carb side, gas is flowing freely.

Checked carb itself, all jets are clean, plunger moves freely.

I think it is somthing electrical personally. Maybe a bad CDI. But would the bike run for a few mins, then just cut off. The CDI is not getting hot.

Could a Stator going bad cause this?

I pulled his spark plug, and ignition coil and installed on my bike, both work fine fro 30 plus mins, so odds are its not either of those.

I guess next step would be to let it cut off, and pull plug ASPA, and see if it is getting spark before it cools down..

If it is not getting spark (while still hot), what would be my next coarse of action. CDI, Stator, Ignition Coil, etc????????

[miles Machine]

sounds like a stator..what it sounds like is happening is that your getting some insulation breakdown when it heats up. you can check it your way letting it heat up then checking spark but thats still not going to be conclusive that its the stator, because your checking the system as a whole....i would let it run till it shuts off then quickly check for ib, ac volts, and resistance at the stator plug...referencing your readings against the manual

[proctorbc2005]

Originally posted by miles Machine
sounds like a stator..what it sounds like is happening is that your getting some insulation breakdown when it heats up. you can check it your way letting it heat up then checking spark but thats still not going to be conclusive that its the stator, because your checking the system as a whole....i would let it run till it shuts off then quickly check for ib, ac volts, and resistance at the stator plug...referencing your readings against the manual

My mechanic said the same thing.(should have called him first)
Ill give it a shot today. Ill post back and with results. So if some one else has this issue maybe I can save them some time and effort.

[proctorbc2005]

Got if figured out...........

Turns out it was the Stator after all. I applied the multi-meter to the output wire just after the bike cut off, tried cranking, and nothing, it was dead.

Waithed about an hour and tried cranking again with meter hooked up, and it was pushing 12-13 volts.

Replaced the stator, and now it runs like a scalded dog. Rode it for almost an hour, no issues.

To all, thanks for the help.