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Accelerater pump diaphragm break down

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What's up guys!? I have a 2005 yz250f that was very much neglected and left sitting for about a year. I got it running, rebuilt the engine, top and bottom, as well as replacing numerous parts around the bike.

I got it running but notice it like to bog around mid throttle, so we decided to replace the accelerator pump diaphragm. And sure enough we went in and the diaphram was in prices. We replaced the diaphram with a new oem one. Went to run the bike and had some trouble. At first it would only run with the hot start fully open, needed more air right, adjusted the fuel screw, now it will only run with the choke. We went in and cleaned everything out and there were some rubber prices in the drum.

Looked at the accelerator pump diaphram and it was all in peices!?!? WHATS GOING ON!?!

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Did you clean , then open to find the diaphragm in pieces ? Nothing other than 91-93 octane or possibly something like sea foam should be going anywhere near the fuel system don't use fuel antifreeze or octane booster as these are tough on rubber or carb cleaner unless the carb is being rebuilt .

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Can't use carb cleaner on rubber parts unless specifically for motorcycles.

 

You need to clear the passages now that you have diaphragm debris everywhere.

 

There is a sideways passage right under where the float bowl cover seals, which goe up to the apump spray nozzle.

 

Spray brake cleaner in there to see if it's free.

 

If you see any corrosion anywhere , you might need to soak your carb in Pinesol for a couple of days before spraying out the passages.

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We did use carb cleaner to clean it out and were running premium non-ethanol gas.

That will do it. Never use 'carb cleaner'.

There are internal rubber parts that you cannot safely get to that the carb cleaner will dissolve.. Residual solvent will eat the diaphragm, slide seal and orings. You can only use car cleaner on a carb you can safely remove all rubber and plastic/nylon parts.

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