Hi everyone,
I bought an 09 CRF250R with a blown bottom end. I split the cases and replaced everything with OEM parts. I had the head rebuilt with new OEM valves by a local machine shop. This included springs, valves, seats lapped and surface faced. Every single bearing and seal was replaced.
The bike started and did a total of 2 hours riding. It stalled when an inexperienced rider stalled by dumping the clutch. It has never started since.
Valves
I've checked the valves as below, both are marginally loose:
Intake - 0.09 to 0.15mm. An 0.18mm feeler gauge won't fit, an 0.15mm will fit fine.
Exhaust - 0.25 to 0.31. I can 'force' a 0.33mm feeler gauge in, any bigger won't fit.
I've left the valves loose as I understand it will tighten up relatively quickly on a newly built head. The plan was to check at 5 hours.
Attempted the decomp pin mod, without pictures it was difficult, though only kept a small 'nib'
Carb:
I live in Perth, Western Australia at sea level. Currently Summer and has been mid 30's (86 to 104 F)
Idle: #40
Main: #180
Choke: #68
3rd clip from top
I've disassembled and fired compressed air all throughout. I've replaced all jets except choke.
Spark:
First kick is nice and bright, subsequent sparks look 'normal'. I don't know what a weak spark looks like
Air:
I've been trying with no air filter - direct open carb intake
I've sealed the airbox boot liberally with black silicone.
I've sprayed starting fluid down the throat of the carb, not even a burp.
I've used fresh 95 octane. I don't know what equivalent that is for the states
What in the world do I look at next? I'm about to throw this damn thing in the bin -- But I've spent an obscene amount of money on it as a fun project.
It's not fun anymore
Any help leading to the bike starting, I will honestly buy you a beer.