E-start problems after crash / battery kill

I have an 03 WR450F.

Last summer I had a crash and was hit by another rider, stripping out my kick start gear. I got up and started it with my trusty E-start. Later in the race I stalled bike in a turn and it would not start with E-start. In my frustration I pushed the starter button continuously until the battery died. Race Over! Since that time I replaced the kick start gearing and the kick start has worked ok since then.

The E-start however, has never started the bike (even after battery charge) since the race. I took the bike to my local dealer's service dept and they checked the bike over and could not find out what was wrong. Per the service manager he called the Yamaha techs and they could not come up with a explanation. I'm looking for ideas on what might be wrong.

Luckily my friend has the same bike and offered to let me borrow it for parts exchange. Here are the items I switched to rule out problems:


Starter Motor

Ignition switch

CDI Unit


Starter relay diode

Starter circuit cut off relay

Ignition coil

Add'l Info: The bike starts with the kick start (not as well as before the incident, about every 5th kick it backfires, but it starts). My woodruff key was replaced and rotor lapped long ago without prior failure and no problems since. The carburetor jetting was not changed (Ran great. Started first time,every time). Starter motor is turning w/ button push and you can hear engine turning over but no starting. Checked spark with kick and E-start, looks the same. Once the bike is started it runs great.

When my bike left the shop the service manager said they had done everything they and Yamaha could think of to fix problem. My question to him was "So I have to live with a bike that I bought due to electric start and there is nothing you or Yamaha can do?" He had no answer.

Sorry this post is sooooo long, but I know info is important.

Thanks, Frustrated Yamaha Owner

Hook it up to a new battery and try the e-start.

Gray wire Mod.

New spark plug.

Check valve clearances and cam timing.

Check Auto Decomp on exhaust cam is working and not binding.

Kick start should work with 2 to 3 kicks if bike is OK.

Replace the starter motor if all else fails. :D

Dealers should be able to figure this one out. :)

I tried new battery, new spark plug, new starter motor, grey wire mod done long ago. Once bike is warm will usually start w/ first kick. Sometimes after a few kicks the kick starter seems to bind, but can be agressively kicked through. Is that the auto decompress not working right? The electric start will do the same. If it binds I kick through it and then starter motor turns - but will not start bike.

If the valve clearances and cam timing were off wouldn't bike run rough?

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