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WHEN I STAB MY 450R, IT STARTS

February 12, 2009
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Dear Boss,
I have a 2007 Honda 450R and installed an HRC kit within the first week I owned it. I purchased the service manual and followed the kit instructions to a tee. The quad runs great and there’s no hesitation anywhere when working the throttle. The problem I’m having is on startup. It’s a pain the way it cranks over forever, especially after sitting for a week. If I stab the throttle a few times before hitting the starter, it seems to start up easier, but something still seems wrong. I checked the valve clearances and they’re fine. Some people say it’s the carb adjustment or not enough fuel in the float bowl. I turn to you because you’re the expert. If you could provide me with advice, I’d appreciate it.
Michael Durante
West Milford, New Jersey

Sounds to me, son, like you have a lean condition when starting because by “stabbing” the thumb throttle, you are causing the accelerator pump to squirt extra fuel into the intake. This obviously helps with starting. Go ahead and check the float height to see if you do indeed have enough fuel in the float bowl. When your quad is operating at anyplace above idle you say it runs “great” so I can assume the problem has nothing to due with any metering circuit above idle. If your float level checks out then we have to look at the idlepilot metering circuits. At idle you have the pilot jet feeding the idle mixture screw. Try increasing your idle mixture by turning the idle screw out about a half of a turn at a time and test the hot idle as well as the cold starting. This could take awhile due to the cool down cycle. If you reach about three turns out on the idle mixture screw then consider going up to a #50 pilot jet and return the idle mixture screw to about 1-1/2 turns out and start testing again. Chances are you will come up with a setting that is acceptable.

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