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Who's done Air Cut Valve mod on 03 WR250F

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Ricks thumper FAQ is inconclusive about the ACV on 03 mods whos done it and is the procedure the same as for 01 and 02.

I want to do it his way as quoted below.

Remove ACV cover and carefully remove the spring, the diaphragm.

Using a leather punch cut a small plug from an old inner tube that fits snug in the whole in the small O-ring.

Cut a small round piece of material (such as an inner tube) that will cover the cavity with the door and the small port in the top.

Replace the diaphragm in the ACV cavity backwards with the pin pointing out.

Replace the spring and the cover.

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The reason the FAQ is "inconclussive" is that in 01/02 there was no concensus on the best way to block this circuit. There are probably multiple ways to inactivate the circuit so that is probably the reason.

My thinkning was this: the YZF has no ACV. It has neither air passage, does not have the valve, and does not have the spring and diapragm. So by blocking both passages as well as the valve, this would simulate the YZF exactly. I left the sping and diaphragm in simply to ensure that the "patch" was held over the valve so that there would be no "leakage." To complete the process you have to replace the pilot air jet with the YZF spec.

As far as I know, there is no difference in the ACV on the 03 model as compared to the earlier models.

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Thanks Rick. I just did the mod with your procedure and took it for a spin. Definitely leaner on close off. Im yet to do the jetting. I have a race tommorrow so will get it sorted after that. Which jet needs changing and what to at sea level.

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