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About DarrellBeer

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  1. I own a xr650r dual sported. Three years ago I road with some friends in Moab and found that as i went up in altitude It ran much richer than any previously owned bike. In fact it nearly would not run at all. of course I went back to the hotel and lowered the needle. This helped but without re-jetting it was just a bandaid. As a former pilot of ultralight airplanes we dealt with this problem all the time. So I started dreaming. This is my solution. I purchased a o2 sensor on the exhaust with the gage near the handle bars. this gives me the fuel mixture at every throttle setting and at different altitudes. Next using the free air from the intake box ( after I removed the calif. smog ) I ran it to a small needle valve from Grainers, then back down to the intake manifold nipple used for the smog system. This is basically the same system used to lean airplanes at altitude. Free air into the intake manifold to lean the engine. I plan on using this only to ride over mountain passes, not for continuous riding. I will let you know how it works in about a week. If you would like to see pictures you can take a look at my web sight darrellbeer.com