Need help with my yz426f

bike rider said:

:bang:


Just bought a bike that had been sitting for a while. Bout 2 years. Didn't come with a manual when I bought it so I need some help trying to figure out how to start it when it's hot. No problems firing what-so-ever when it's cold. But can't figure out how to start it after it's been running for longer than 20-30 minutes. Does this bike have to be re-jetted for elevation? I live at sea level and I go up into the mountains to ride, about 6,500 feet. Any help anybody can offer would be much appreciated.

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Yes, this bike will run very rich at elevation, if you normally ride at anything above 3,000 ft you should probably rejet, although this will vary w/ rider and climate/season.

Your bike came equipped w/ a hot start button on the carb, it is red (the choke is the black knob). Pull this out to lean out the carb, sort of like a reverse choke. It actually opens an extra air circuit to lean out the mixture.

It also helps to "clear" the motor by holding the decomp in and kicking several times to rid the motor of any unburnt mixture due to flooding. Clear it a few times w/ the hot start pulled out and it should fire (it probably won't idle w/ the hot start engaged so be ready for this).

A lot of 426 owners bought the Zip Ty or Dr. D kits to relocate the hot start actuator to the handlebars (like the CRF and YZ 450) to make this easier.

Do not operate the throttle when starting, your bike has an accelerator pump which squirts a ton of gas into the cylinder every time you twist the throttle. A lot of 426 owners, myself included, have benefitted from tuning the pump to deliver less gas. If you like to tinker or aren't satisfied w/ the 426 throttle response as delivered (and lots of folks aren't) go to thumpertalk.com and search for "BK mod." You can also get some good jetting advice there, the site was founded on the WR/YZ 400/426.

Hope this helps.