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2001 Yamaha Yz426f problems and how to fix em

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Hello, I have just recently bought a 2001 Yz426f and found out that the head pipe gets glowing red in minutes of it idling now i know that is a common problem in the 02's but im not to sure if it is with the 01's, It unfortunatly has the auto decompression release which to some people Im sure its nice but personally i wish it had the release lever but thats just me. Now another problem i have is that when its idling it will start to overflow/spray antifreeze out from somewhere in the engine (havent found out where or taken great notice to where it is since i just bought it today and saw it a little while ago) but i would love to know how to fix these problems or atleast the anti freeze problem unless the redness of the head pipe is not a good sign then id love to figure out that problem to.

Thanks,

Toric

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426's do not like to be left idling for long periods of time as (a) the header will glow, and (:smirk: they will start to spew coolant.

Best idling is kept to a minimum (max 2 mins).

When riding with an airflow, the coolant level should settle to be just covering the core (note let the bike cool before checking as otherwise hot coolant will discharge out the from the outlet).

If more coolant is lost so the cores keeps being uncovered, you may have a leak.

See the stickies at the top of the YZ web page, the glowing header is mentioned there.

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Its normal for head pipes to glow. Coolant spewing is normal also if u let it idle too long. I have the same bike and pukes coolant if I don't keep it moving.

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It could be a jetting issue with the carb. Its running to lean. After a couple of min if it is just starting to turn red then that is normal. If it is turning red within a min or less it is a jetting issue and the carb needs to be cleaned and possibably jetted to richen it up.

The antifreeze is normal after a few min. If you are worried about it get some engine ice coolant. You can get it at most of you bike dealers. It will help the cooling but these bikes has to keep moving to keep them cool.

I have a 99yz400fl1 and it does the same thing once i got my carb and valves adjusted.

Hope this helps

Chad

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It could be a jetting issue with the carb. Its running to lean. After a couple of min if it is just starting to turn red then that is normal. If it is turning red within a min or less it is a jetting issue and the carb needs to be cleaned and possibably jetted to richen it up.

I beg to differ. turning bright red in 30 seconds is abnormal. Turning visibly red within a minute is just how they are. As far as coolant, a 426 running at normal temps will only idle for about 45-75 seconds without tossing something out of the overflow.

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If it takes a couple minutes for the pipe to glow red, i wouldn't worry about it.

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now my bike also back fires alot while idling and reved up a bit is that normal to do that and i have a jetting that can be turned up or down (drawing a blank on the name) but its a mod to the carb has 4 settings but im not sure if up means open more and down means closed or up means close and down means open.

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now my bike also back fires alot while idling and reved up a bit is that normal to do that and i have a jetting that can be turned up or down (drawing a blank on the name) but its a mod to the carb has 4 settings but im not sure if up means open more and down means closed or up means close and down means open.

http://www.thumpertalk.com/forum/showthread.php?p=3710599#post3710599

http://www.thumpertalk.com/forum/showthread.php?t=696672

http://www.thumperfaq.com/jetting.htm#PJ

http://www.thumpertalk.com/forum/showthread.php?t=327405

Read them in order. Guess where they were, BTW.

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well how am i supposed to fix the idle if i cant let it idle for to long haha

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