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carb adjustment question acclerator pump

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Well short story long, bike wouldnt start for me the other day...until i tried starting it like a two stroke and giving it some gas, which i havent had to do in three years. So i immediately thought a jet was clogged. bike wouldnt idle all damn day. got home and tore the whole thing down. cleaned a bunch of jets, and still didnt get the thing to start(even worse now). anyway still working on it..now i think i might check the timing. the question is....at the top of the plunger for the accl pump, there is a screw on a black lever/set screw. What is this adjustment, and how to set it???? Thanks. :thumbsup:

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Well, it sounds like you are referring to the pump timing screw. I'm pretty sure its adjustment is covered in the owners manual. The screw adjusts the movement of the pump w/ respect to the throttle. You want the pump to operate after the throttle has lifted the slide out of the way. The pump stream enters the venturi behind the slide, and you don't want the stream to hit the slide.

I believe there is a spec. for number of turns of "slack" in this screw, this would translate into delay between movement of the throttle pulley on the carb and the downward movement of the pump arm.

Anyway, it doesn't sound like this is your problem. Remember the pump is only operating while the throttle is moving. So if the bike won't idle the culprit ain't the pump.

Hope this helps.

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thanks...ill check ou the manual. checked the timing this morning and its perfect. I still think its fuel realted, but dont know what to do next. I ripped the whole thing down, and cleaned every jet i found

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When CRFs get hard to start one of the 1st things to check is your intake valve clearances. Your valves might be leaking.

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