426 overheating

[zaxcar1]

i have a 2002 426 and i got my step kids staring to ride. well i have to ride behind them and my bike seems to run hot. and when i had to climb a steep sandy hill it was boiling over when i got to the top. so does any one have any tips that might help, or know any fixes??? OO

[NMdesertRacer]

I would try Engine ICE! But if your not getting sufficient airflow through the radiators nothing really gonna help. These 4 strokes heat up fast unlike 2 stroke.

[Gunner354]

There is really only one choice to stop this.

Evans coolant. It's waterless and will eliminate boil over.

www.evanscoolant.com

[grayracer513]

Let's suppose, briefly, that there's something actually wrong with the engine. Do you think that a special coolant will fix it?

426's typically run a little on the hot side at low speeds, and will normally overheat after about 1-1 1/2 minutes of idling, but I don't see being overheated at the top of a climb as very normal. That sounds a bit more like a head gasket.

Besides, on an 8 year old bike, there are a few things to check before you decide that you need to spend $40/gallon on some magic elixir:

• Is your cap holding its rated pressure, or is it worn below spec?
  
• Is your coolant fresh, and mixed at near 50/50 with water, or is it old, acidic, and diluted?
  
• Is your radiator clean, inside and out, or is it coated with mineral scale and partially plugged up, with blocked or damaged fins?
  

If all that looks good, and you still have the problem, the head gasket sounds like a suspect, particularly where it heats up on a climb.

There is only one way for a coolant to decrease boil over compared to another, and that's by raising the boiling point. None of them really cool the engine (move heat from the head to the radiators and out) much better than the other, and not one is as effective in that regard as plain water. In the case of Evans, that means that by the time it ever did boil, your engine would be over 400 ℉, and you might find yourself running at 300-350 for half an hour without ever knowing it. The only upside is that if you did become aware of it, and let it cool for a bit, you'd still have coolant.

[zaxcar1]

like i said before, i was riding behind the kids (slow speeds) and when i went up the hill the one boy was gitting stuck so i got a slow start up the hill. i was in 1 and 3/4 gas, and was going no more then 5mph. so i figured that the slow riding and going up the hill at slow pace and engine at high rpm maid it over heat. and the low air flow in the raidators didnt help.

[fosbibr]

As Gray says, Engine Ice only raises the boiling point.

I have a WR400 that has been running hot - I have an inline temp gauge and I can see my temps. As a 1st step to determing what was causing the overheating I flushed (vinegar / water mixture) the radiator and replaced with EI. I'm still running the same temps.

My dad was riding the WR while I was riding my '08 YZ450 and the YZ was fine. So I know its the WR's problem.

[Gunner354]

Gray why the attitude?

You have never used Evans so how can you make an assumption? I have and I have used others.

I was assuming all things were checked mechanical.

It would be nice to stop the attitude and the know all mighty when you don't know it all and have NO experience with Evans. Some of us are very competent and have years of experience that you are not aware of because we are a little more humble.

[grayracer513]

You have never used Evans ... and have NO experience with Evans.

You make this assertion based on what evidence?

And while we're at it, why would any experience with the product be necessary to know what is a quantifiable fact of simple chemistry?

Evans has it's place. But it will not solve every system issue that comes along as if by magic.

[grayracer513]

like i said before, i was riding behind the kids (slow speeds) and when i went up the hill the one boy was gitting stuck so i got a slow start up the hill. i was in 1 and 3/4 gas, and was going no more then 5mph. so i figured that the slow riding and going up the hill at slow pace and engine at high rpm maid it over heat. and the low air flow in the raidators didnt help.

That's a little clearer picture. Go through the list I posted to be sure nothing's amiss there. If you're suspicious of a head gasket, there should be coolant loss beyond the point where the coolant covers the radiator tubes with NO external leakage, while riding at a pace fast enough to prevent boil over from lack of air flow (which does really take much when all is well). Eliminate the minor things first.

Regarding coolants, you may find that you simply ride in a manner that taxes the cooling system to the extent that a higher boil point is the only way to prevent boil over, in which case something like Evans is the ultimate solution. For some woods riders, there just isn't a way around this unless you can rig an electric fan system. Your choices are (Listed with the approximate boil point under 16 psi (1.1 bar) of pressure) :

• Water (235)
  
• Water with a surfactant like Water Wetter (still 235, but cools better)
  
• Ethylene Glycol coolant and water @ 50/50 (Green Prestone, Coolanol) (265)
  
• Propylene Glycol and water @50/50 ("Safe" anti-freeze, Engine Ice) (~270-275)
  
• Evans coolants (375+, depending on blend)
  

[Gunner354]

You make this assertion based on what evidence?

And while we're at it, why would any experience with the product be necessary to know what is a quantifiable fact of simple chemistry?

Evans has it's place. But it will not solve every system issue that comes along as if by magic.

Your prior posts.

You have great info but it's really to bad that you are in your own little condensending world. If it's not your idea or fact than it's not right. There are some very smart and experienced people in this forum other than you!!!!!

[grayracer513]

So then, in your view, because I think that someone should first address the potential for his cooling complaint to have been caused by a faulty condition within the system, rather than rushing out and buying the second most costly coolant on the market to slap on it like a band-aid, I'm condescending?

Fascinating.

I do have direct experience with the product, BTW, but not in my own vehicles.

[NMdesertRacer]

If your bike is fine any other time you ride it but while riding behind kids going at very slow speeds you bike is overheating because of lack of airflow. i know from experience.

[bluemotorcyclesam]

Dito.

[mkporn]

or you could just put different coolant in it such as Evans, assume nothing is wrong and it was simply because it had just regular old coolant in it that has been used succefully for years and wait til the thing melts down cause there are no indications of it getting hot and boiling over anymore...

[zaxcar1]

wow i did not think this would get so heated (lol) i did check and find that my DR.D hot start plunger was sticking once again. so i am going to get a regular one from the dealer. so thank you ALL for all the great info on all the coolants and going back to the start

[grayracer513]

On that subject, I had some trouble with the DRD remote hot start on my son's 250F back when he had that. What I found was that there apparently is no way to keep water out of the carb no matter what (unless you just don't wash it). So here's what we ended up doing.

The first thing was to get the plunger freed up and get it and the bore as free of all traces of white corrosion as possible. I used 30 caliber rifle bore brushes for the clean up, along with penetrating oils. Then I worked some dry graphite into it and lubed it with a dab of marine grease.

From there, a lot of people with this set up choose to remove the plunger after each ride/wash and regrease it. What I did instead was to fire the bike up and then hold the hot start open for several seconds to draw out any moisture from the circuit. It seems to have worked, because once we adopted that program, we had no more trouble with it sticking.

[zaxcar1]

the night before the ride it rained and when i took the hot start out, it had water in there. so i dryed it and lubed it the best i could.

[Gunner354]

or you could just put different coolant in it such as Evans, assume nothing is wrong and it was simply because it had just regular old coolant in it that has been used succefully for years and wait til the thing melts down cause there are no indications of it getting hot and boiling over anymore...

Melts down? Not!

My question is what do you do when all of the coolant is on the ground? Hm melt down?

Most people

are

well aware when they are in an overheat scenario. Well maybe not all from the sound of it. Rather have an engine a little hot and have ALL of the coolant still in the radiator than all of it on the ground.

Another person with all the answers and zero

experience. Simply amazing! Good luck with all of your coolant on the ground!

[TotallyMetal]

I used a catch can from thesame yr WR and it works friggin awesome for me. I am at 6,000 ft altitude most of the time and just spent 4 days at Moab 115 degrees with no problem.

[milk]

good deal on the catch can! i think i'm going to pick myself up one. does it fit under the plate without problem? i'm not too sure i'm really keen on drilling the subframe and putting screws in for a bracket like you have, i'll likely just use safety wire or heavy duty zip ty personally...

...boy that doesn't look like evans coolant in there though??

? i'm such an instigator ?