I have a 1999 Yamaha Timberwolf 250, that I can not get started with the electric start, (starter turns motor over like it should) but will start by pulling the recoil starter. I have changed almost every electrical component there is. I started with a new battery, then I have tried 3 different stator assemblies, new cdi, new coil, now rectifier, a different wiring harness, new solenoid, and a different start/kill assembly on handle bars. The thing is when I turn over atv with starter I have an inline spark tester and showing spark, but doesn't start then I pull the recoil starter it fires up. The battery shows 12.7 volts and 11.7 while engaging the electric start. I have adjusted the valves, I've done compression check, 110psi. New plug. Also another question is, I have key switch on, and jump solenoid but does not spark. I've even tried to use a direct hot wire to starter to turn over motor and no spark, but it has spark when I use the button but doesn't start atv. I'm at wits end and would like any advise I could get.

 

Are you getting good spark with the starter? Spark testers are ok, but I'd ground to frame and visually confirm good blue spark when starter is engaged...


I'd visually compare the spark you get with the starter vs. the recoil...

 

Yes I visually checked spark with plug connected to lead, held it close to cylinder nice blue spark, also about an inch away from cylinder, jump and snap hard. Blue spark. pulling recoil same results. I even sprayed ether in thru carb still wouldn't start to eliminate carburation. I even went as far as changing carbs also to make sure.

 

Did you spray ether down the plug hole? If it won't start on that then it's not getting enough spark or your timing is off...

 

Yes sprayed ether in plug hole, still nothing. I checked timing marks they were on I even took flywheel off to see if key had sheared. All looked good. I am thinking spark or electical is my problem but why is it starting by pulling recoil but not with starter?

 

This is a common problem with CDI ignition systems, and some say it is the timing coil on the outside of the flywheel being dirty or faulty. I maintain a few Hondas that do this and owners get used to using the start button in short bursts, as a spark after the button is released will "catch" and the bike run. I posted about a Honda fault that may explain another reason recently, see Honda 350 neutral gear wire, no idea if Yamaha use the same system.

 

Thanks i'll look into the neutral wire, bypass or do what I need to do with it, to see if it works or helps. But what would be the correct or permanent fix, as i'm working on this for someone I know.

 

Did you replace the starter itself? I know you feel it's cranking the motor over sufficiently, but it may not be and it may be drawing more amps than it should while cranking...


If not then I have seen many threads on the coil...but you mentioned it was replaced...otherwise I'd think there is some kind of partial short in the wiring from the ignition/start button to the CDI..


I'd be curious if you could measure the voltage coming off the plug/cap when cranking it with starter vs. pull start...I mean if there is truly spark coming off the plug when using the starter, ether will ignite...it don't take much to set that stuff off...

 

I have not changed starter that would be the only component that I have not changed or replaced. As for coil I have replaced, no difference there. I also thought about a possible short but I replaced entire wiring harness out. Including the start button assembly. I have not tried to measure voltage from coil wire yet I may try to do that tonight to see what I can determine from that. I would assume it would be dc voltage, correct?

 

I also tried touching the starter with a hot wire from a different battery to turn it over so I wouldn't be drawing any current from battery of atv. The starter turned over but odd thing was no visible spark. So I was just virtually manually turning motor over with starter. But then I went and pulled the recoil starter it started. Very strange, I'm obviously missing something.