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06 YZ450f Overheating, stalling?

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I have a 2006 YZ that seems to get really hot, then stalls. I ride mostly single track, first gear slow stuff. 5000-8000ft elevation.

Once it stalls it tough to start. Hit or miss with the hot start.

Goes through a bunch of coolant. Need to add 6-10oz per ride. I don't think there are any leaks but....

Has fresh motor (2 rides), jetted correctly (by local shop), carbs completely gone through. The bike rips for a while then wants to stall. If I pull in the clutch for a few seconds, it stalls. Really need to stay on the gas for it to keep running once its hot.

Also has a big gas tank on it. Can these affect cooling?

Air temp has been cool (50ish)

Kind of a pain when it stalls in the rocks!:smirk:

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yz450f cant stay in first gear slow stuff for more than 5 minutes they want 30mph on fourth every 5 minutes

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Get an aftermarket water pump this is gear driven off of the crank the speed of the water pump depends on the RPM. After market pump's increase flow.

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Cover that clutch in the tech. Focus on keeping the motor running and then technique and then speed in that order. I read all about thumpers overheating and puking coolant when I rode smokers but my YZ250F don't overheat on the tight slow trails. Must be 450 related.

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well, funny i had almost the same issues, but i ride single track with my 06 yz450f, but basically one when it got hot it would yeah basically start to spew out some coolant... one day it decided to that bad, so now im low on coolant so i thought i was still fine as it usually dont leak that much, well i was wrong there.... long story short on that... new valve seals,

now to the point, fix it, chances are is your seals on your water pump, replace your seals and water pump shaft, what it turned out to be on my bike is there is the 1 bold that holds down the metal Y that comes up from the pump housing, turns out it wasnt screwed in all the way due to a bolt just a bit too long, so yeah,

i got some awsome aftermarket rads for my bike, double thickness, and like double the coolant flow, it also holds some more coolant so that can help, I will include a link for you, basically they are made by CX Racing, back in the day they where 450$ for both, now they are like 60$, but yeah made with Air craft grade alluminum, hand welded, and each one inspected for leaks and so on, cx makes quality parts, and the stock rads are crap really any how.... so if you ride single track i would highly recommend buying a pair of these, its only like 120$ link to cx racing and ebay http://www.cxracing.com/mm5/merchant.mvc?Screen=PROD&Store_Code=CXR&Product_Code=RAD-YZ450F-LEFT&Category_Code= and http://cgi.ebay.ca/AL-Left-Radiator-Yamaha-2006-YZF450-YZF-450-YZ450F-YZ-F-/250765080323?pt=Motors_Car_Truck_Parts_Accessories&hash=item3a62c37703

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Gonna try a 1.8 lb radiator cap and some Redline water wetter.
That's 1.8 BAR, not psi. Your stock cap is 1.1 bar. "Bar" is a contraction of "barometric", and 1 bar is .987 of 1 atmoshpere, or 14.5 pounds.

A 1.1 bar cap is 16 psi. A 1.8 is 26.1 psi. You better be sure your hoses and radiators are up to that.

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My OEM radiator cap is due for changing since it had been sitting for so many years the seal was dried out and damaged. I havent ridden the bike yet so i have no clue on how hot it will get. Question is should I use an aftermarket 1.6 bar cap

http://cgi.ebay.com/ebaymotors/YZ250F-YZ450F-YZ-250F-450F-HIGH-PRESSURE-RADIATOR-CAP-/380346586670?pt=Motorcycles_Parts_Accessories&hash=item588e6c562e

or a stock 1.1 bar cap???

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1.1 bar is 16 psi, and should be adequate for most cases. If you spend a lot of time on slow, technical trails, you may benefit from the 1.6 (23 psi), but you'd better be sure your hoses, etc., are up to it.

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