426 jetting

My 426 is fouling plugs as often as twice to five times a month, usually just after sitting for a week till I can ride on the weekend. I have the full system fmf Ti 4 exhaust and an external air/fuel adjustment screw and no matter how I adjust it, it still fowls plugs and its getting old. Should I get it rejetted? Any suggestions welcome. Thanks

Can't get you pic link to work.....

First of all always turn the fuel off at the end of a ride and let it burn up the fuel til it dies. I would suspect a high float level since it seems to do it after sitting. Maybe too big of a pilot also. :thumbsup:

You may think this is stupid. My 426 fouled plugs everytime I rode it. I changed air filters ( twin air ) and it not not foul another plug until I put the stock filter back on, I did that because it was clean and it was race time. AS soon as I tried to start it, it fouled the plug. The stock filter is in the trash and no more problems. I was told it had to do with air flow.

How long does the bike normally run with the fuel turned off? Mine seems to go on forever.

fix pic link, thanks for letting me know!

1 minute or so, maybe a little longer.

I had the same problem for a long time and would foul plugs non-stop. I read all the posts about air filters etc. They all had some positive effect, but non like what I finally did last. I took a few hours aside from riding to remove the carb to do a complete cleaning. If you've never done this, read a few posts about it and you'll be a master. I put it all back togther with the stock settings and jettings. Then I implemented a storage procedure I came accross on an old post a long time ago. It is as follows. When I come off the track or finish trail riding, I turn the gas off on my way back to the pits. I take a few turns in the pits and goose it a few times to get the gas burned out. If it is still running, I just let it idle there until it stalls. Then I push on the kick starter until it wont move anymore. It is the point where on my 01 426 you'd have to hit the decompression lever. What this does I guess is keeps it at top dead center and prevents fuel from migrating into the engine compartment. I swear on my mother's life, I did this a year and a half ago and have not changed a plug since. I was so frustrated because I would have to change a plug before every ride.

I hope this helps, but one negative result of this fix is - I don't clean my air filter after every ride like I used to. Shame!!!! - Shame!!!!

Check your AC pump timing.

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