Confirmation On Carb Issue

[cbr rob]

I'm in the process of restoring a 1987 CR250, and before the final teardown, I need to make sure everything is working like it should. The bike starts and runs fine, but it instantly dies when you let off the throttle. I know that this bike runs the PK Kehein carb, which incorporates the idle control and choke. When the choke is on, the bike will idle and run fine.

I believe the pilot circuit is plugged which is why it dies so quickly when you let off the throttle. Is this correct? All that is needed to keep it running is to have the throttle cracked. Thanks for any help.

 

[TimberPig]

Yes, that is correct. If the pilot circuit is plugged, it cannot pull fuel through the pilot circuit to run on. With the choke on, it is pulling fuel through the choke passages, and running on that.

Clean the carb out paying particular attention to cleaning out the pilot jet, and all the internal passages of the carb. Pull all the rubber components out, then hose out the passages with carb cleaner, and then blast the carb out with compressed air. Reassemble and your problems should be fixed.

 

[cbr rob]

Thanks for the heads up, Timberpig. Just wanted to make sure I was looking in the right direction with this one. Thanks again.