Cooling problems?

I just bought a 2001 426 and I have a question.

Has anybody ever had problems with their bike overheating? Mine has'nt yet, but I want to know what to expect this summer, especially in the sand. I would assume that they made a compenant cooling system for them.


I live in N Calif, and it can get 105 here in the hills. I dont ride then but, The YZ handles it good, I have not heard of overheating as per-say, but others have posted they had problems.

This will start a mail sotrm of inofrmation but bottom line is Yamaha did a good job at keeping them Cool I think..

Just FYI

There wil be a bunch or replys on coolant what kind and debates on it. Just make sure of one thing DO NOT GET COOLANT WITH SILICATES in it, Bad for aluminum.

Search for coolant and you will get a Crap load of info

Hope it helps

Oh ya I did my research and found that Texaco/Havoline (PG Type)-(Orange) was pretty much the same crap you buy for 1,000 bucks an oz from the shops (Just Kidding) but its the same stuff and you dont have to waiste money on gimmicks and name brands

[ May 03, 2002: Message edited by: EgoAhole ]

Hey EgoAHole this is the first serious post I have seen wrote by you man ! Congratulations !!! :)

You dont read much do ya :)

I ride in FL and it's usually muggy hot and I've had no problems at the track. I don't do a whole lot of slow riding, but I have ridden around in 1st on flat roads while my wife followed me on her XR100 and it got hot but didn't boil or anything.

I've ridden both a YZ400 and a YZ426 at the dumont sand dunes near death valley Ca. Ambient temperature was roughly 119 at the highest. It wasn't much fun and there was alot of heat coming off the bike but it never whimpered. The stock cooling system is awesome.

also run engine ice or water wetter( i like water wetter)the stuff really works

BTW, you might find that you can't keep the radiator(s) full to the cap. With thermal expansion, it's normal for the system to spit out some coolant until it reaches equlibrium. All that means is that once the engine is stone cold, you will probably find that the coolant level is a little below the neck flange. I check mine before every ride and it stays at that level. If I try to fill it to the neck, it spits it right out. I also use Water Wetter and it seems to help to some degree.

Ive boiled the **** out of my yz400 a few years ago. Ridding REALLY slow technical single track with alot of clutch abuse. Also it was like 95 deg. Ive added Redline water wetter and a vented front number plate. I also drilled a series of holes in the black plastic guards over the radiators in hope of getting more air through them. I havent boiled over since then. have no idea if the stuff I did helped or not.

I tried to get the boysen water pump that they advertised but when asked boysen didn't have a clue what I was talking about. Ive also heard that unpainted radiators displace heat better than painted ones. I was thinking of getting mine striped but never did.

Ive never boiled mine over either. But for coolant , Ive always run distilled water, waterpump lube(water soluble oil) and water wetter. Never ever had a problem. I started using this mixture when the case on my CR rotted out (a couple of times) using the manufacturers recommended coolants.

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