crf running like shit, need help

[burnham]

Mt buddys '02 CRF 450 is running bad. (Has stock engine/exhaust.) When the bike gets hot it is stalling a lot, and it is a bitch to start. The bike stalls a lot when hitting ruts/bumps/roots. When he re-starts, it likes to stall if he gives it any throttle.

The bike probably has 150 hours of trail riding on it. He pulled the carburetor, everything looks fine. He checked the valves, said they were within spec but 1 thou on the tight side of things.

What should he check next?

We are supposed to ride the Hatfield McCoy trails this weekend, so this is sorta fucking things up.

Thanks, Todd

[Paul_E_D]

The basics. Fuel and spark. Tank Vent one way valve, clean air filter, test coil, test stator, clean or replace kill switch.

[R7]

Do a compression check, even though the valves may be in spec, they are known for slowly failing. 150 hours is quite a bit in the dirtbike world.

You are going to LOVE Hatfield & McCoy trails. What trailhead are you staying near?

[burnham]

We're staying near Bearwallow. The plan is to ride dirt for 3 or 4 days, then park the truck/trailer somewhere and ride streetbikes for a few days.

[butcher bergs]

When the bike gets hot it is stalling a lot, and it is a bitch to start.

This right here makes me think "running lean".

You guys check for intake leaks?

[burnham]

This right here makes me think "running lean".

You guys check for intake leaks?

yeah, we did. haven't checked the electrical end of things yet, we'll probably do that then check compression.

[med00F4]

Valves are too tight. Hot start problem is common with those. The early years they used sucky materials.

[R7]

We're staying near Bearwallow. The plan is to ride dirt for 3 or 4 days, then park the truck/trailer somewhere and ride streetbikes for a few days.

Bearwallow is fast and fun

[burnham]

accelerator (sp?) pump circuit had some fudge in it, no fuel was making it out of the port.

[med00F4]

Glad you got it fixed. I'd still check out the valves and seats. Thats a lot of hours on a dirt bike.

[lrrs313]

Glad you got it fixed. I'd still check out the valves and seats. Thats a lot of hours on a dirt bike.

Big +1. Pull head, have the valves, seats, etc. checked by someone who knows.