[blackedout96]

I bought an '02 CRF450R last year that took some time to get started when I went to look at it. It was a decent price, so I just figured I'd take it anyway.

I rode it for about an hour the following day until it just quit... It wouldn't start at all after that. I checked the valves, they were tight and one of the intakes took the smallest shim in my hotcams kit to get into spec. With everything in spec I tried starting it and still nothing.

I checked the other two usual suspects... Carb and spark. I cleaned the carb spotless, spark seemed a bit weak. Threw everything back together and again, nothing.

With the valves being maxed out and seeing weak spark I installed a brand new head with stainless valves and also a new stator. Also new rings while I had it apart. Got everything back together, checked spark and it was noticeably better... Thought no way I was going to have any further issues.

Buttoned everything back up, kicked... Kicked kicked and kicked about 100 times and nothing. As a last resort I tried pull starting it... Started right up.

After that it kick started just fine for a couple quick rides around the house. Thinking whatever kink there was had been worked out I took it on a trail riding trip. Got about 30 minutes into the trail and it seized up.

Finally, the answer to everything. The crank, although it spun over fine and kicked as easy as any other 450, was going out.

I replaced the crank, put 20 trouble free trail riding hours on it and sold it to recoup some of the money I'd dumped into it.


Chapter 2.

I just bought a non-running '02. It has a brand new dealer assembled and installed head(got receipts with it), timing is dead on, spark is good(swapped it with another known-good stator just to be sure), valves are perfect, fresh gas, carb is clean, carb slide "plate" is right side up.

Could it be that I'm back to the issue I had with my old bike? If so it's no big deal, I bought the bike fully planning on a project.

Just amazes me that a crank that shows no signs of trouble... Spins over with ease and doesn't make any noise could keep these motors from firing at all.

[crfsonly]

can't see it being the crank. recheck the valves, check for spark, fuel, and timing. Has to be one or more of these.