FX Nytro overheating

[Summitseeker]

what happened to the etec to make it inoperable?

A picture is worth a thousand words. The reason it would not run is the spiggot for the gas tank somehow cracked off and leaked out all the gas into the engine compartment and there was no way of fixing it on the mountain.

 

[Yellowknife]

amazing photo's. thanks for posting

 

[mach9]

Somehow cracked off... Ha!!
How about, did the rider got cracked off??

 

[Yellowknife]

Hey guys,

My Nytro XTX is overheating a lot.

Last year when I purchased it, I headed to Ontario right away, didn't have any overheat problems on the trails down there, but there was zero powder snow to play in and it wasn't cold. Got back to Yellowknife in March and the cold weather was finsihed (temps stayed above -20 C)

This year is my first season with the XTX riding below -20 C. Saturday I rode at -38 C and Sunday I rode at -28 C. Both days I couldn't stop the XTX from overheating in loose snow.

The majority of the conditions I am riding through here are cold temps + loose powder.

What's happening is the colder air temperatures are causing slush and ice buildup in the tunnel. This occurs around both the muffler and the bulkhead exchanger. As you know, the snow hits the hot muffler and the hot heat exchanger and turns to water, typically dripping off. Below -20 C the water is dripping down and refreezing inside the tunnel, combining with new snow off the track and creating a solid pack of slush and ice in the tunnel.

This creates two problems. The slush and ice pack that forms around the muffler prevents a solid circulation of snow from being sent to the bulkhead exchanger. The consequence to that is the slush and ice pack that forms around the bulkhead exchanger doesn't fall out. It forms a 'bubble/air pocket' around the heat exchanger, preventing the exchanger from any direct snow contact. The lack of snow circulation caused by the ice pack which forms around the muffler prevents the ice pack around the heat exchanger from being cleared out periodically. Instead all of it just builds up and freezes while riding. A small air pocket is created between the bulkhead exchanger and the actual ice pack. The result is no snow contact on the heat exchanger and no cooling of antifreeze.

What's interesting is that the tunnel protectors act as a support/trap for the slush and ice pack - the tunnel protectors actually enable the ice buildup problem, since the slush forms between the tunnel protectors and freezes to them creating a solid block that prevents any new snow from being properly cycled through the bulkhead exchanger.

I need a solution. I've discovered that I can't ride the sled below -20 C which is more than half our winter up here, without overheating. The problem has ruined a couple of trips now and doesn't look like it will go away for me.

The looser the snow is that I drive through, the worse the problem is because the more snow that enters the tunnel, the more slush and ice form around the only heat exchanger on the sled. Who knew that driving through loose powder would cause the engine to overheat? Usually a lack of snow is the reason for the problem ;-)

The most obvious solution to me is adding another heat exchanger - I didn't know the MTX tubular exchanger would fit - I read through this thread quickly, am I correct that it will fit? My Nytro MTX has not had any overheating issues in the same environment through 10,000+ km's. The extra tubular heat exchanger that is in the tunnel, added with the generous amont of clearance between the track and the top of the tunnel on the MTX aid in the cooling. The lack of any additional heat exchanger on the XTX plus the low amount of tunnel clearance is preventing the sled from cycling old slushy snow and ice out and new snow in.

I can find the P/N for the tubular heat exchanger off the MTX from Yamaha Canada (P/N 8HA-1241A-00) but I can't find a "kit" of any kind online for Canadian Dealers.

The other potiential solution which is more of a long shot I think is to remove all of the tunnel protector bars which I think some of you have tried. Did that help? Again my problem is different since it has nothing to do with not enough snow.

Those are the only things I can think of. I had to drive home today with the hood removed to increase airflow to the radiator, and at -30 C with full wind at my chest I froze my #*$&@ off with no windshield protection. I had to couple that with stopping every 10 minutes to manually clean out the bulkhead heat exchanger and the surrouding snowpack.

This is another one of those cases i've had here where the extreme temperatures I am using the unit in are causing operational issues, and we don't find out about these problems until we're using the units in the cold. The sled just isn't operable in this state and I don't want to cause any engine damage from the overheat light coming on every 10 minutes.

Let me know what you guys think. I'd like to try to get a solution implemented as soon as possible so I can get back on the trails with it. In the meantime I won't risk any overheat damage and it certainly isn't worth the hassle on the trails anyway so I will park it below -20 C.

Thanks for all your help -

YK

Update;

I have some news I want to share with you guys. While it won't address any of you who have added the extra Yamaha heat exchanger kit due to low snow conditions, it will shed some testing for those who have a problem similar to mine with the tunnel becoming blocked with ice due to plenty of snow and limiting cooling through the regular bulkhead heat exchanger.

My dealer (Force One) approached Yamaha Canada on my behalf to entertain a warranty installation of the extra heat exchanger kit on my XTX. Yamaha's Warranty Department declined the claim, however, Yamaha Canada's Product Development Department took an interest in the issue and are providing me with the heat exchanger kit at no charge.

To be clear, the money for this is coming from product development and is not a warranty claim in any way.

My dealer believes the extra heat exchanger will resolve the issue as it has for some of you.

Yamaha has requested in exchange that I provide feedback directly to my dealer including supporting photo's to show the before and after effects of adding the heat exchanger kit in our riding environment. I'll go one better and film it for them.

I'm on the hook for the installation of the heat exchanger. Certainly a deal I graciously accept! I already have the results without the heat exchanger kit and testing with the kit installed will begin in January.

Big thanks to my dealer Force One in Yellowknife as well as Yamaha Canada and their Product Developers.

Also big thanks to many of you guys here who often comment that Yamaha should allow me opportunities to test their products. Over the last several years they've been doing just that, along with other aftermarket companies, so thanks for the votes of confidence guys, I owe the opportunities to you. I'll follow up on here with the results, photo's and video.

Cheers,
YK

 

[**sj**]

good for you as to the cooler running temps...doubt it will completely solve the icing/lack of lube in the tunnel...

I call this anomoly the "flagpole" affect...

the muffler hgets super heated....and the tunnel is relatively cold ...the snow becomes vaporized and remains aloft where water droplets would fall from a heat exchanger and lube....this mist remaining aloft hits the cold tunnel and like a wet tongue to a cold flagpole you have sticking by instant freezing of the moisture...

the one cure is to help "equalize" the temperature differential...this is where a partial block off plate can help...
when the "flagpole" affect is solved...instead of icing you will have water to lube your skid..

 

[Yellowknife]

I think this can be a first step that leads towards the issue of ice buildup, etc. We'll see what develops.

 

[tonesmoke]

hey guys I know mine is a mtx not xtx but mine has only over heated one time while towing a broken sled until I put my scratchers down.Poor guy looked like frosty when we got home!This was with the trail tank.With all the talk I looked and was able to space my radiator out towards the front of the sled about 1/2 to 3/4in.This not only opened up the area behind my radiator but sealed the fairing to the hood better to not allow air to escape forcing it through the radiator.The only reason I did all of this is because we all know a cooler engine makes more power.I do feel the mtx cooler will help most people as I trail ride without issues.

 

[mach9]

hey guys I know mine is a mtx not xtx but mine has only over heated one time while towing a broken sled until I put my scratchers down.Poor guy looked like frosty when we got home!This was with the trail tank.With all the talk I looked and was able to space my radiator out towards the front of the sled about 1/2 to 3/4in.This not only opened up the area behind my radiator but sealed the fairing to the hood better to not allow air to escape forcing it through the radiator.The only reason I did all of this is because we all know a cooler engine makes more power.I do feel the mtx cooler will help most people as I trail ride without issues.

Interesting, any chance you could elaborate or take a photo of what you did to move the rad forward. Cheers.

 

[billymx815]

hey guys I know mine is a mtx not xtx but mine has only over heated one time while towing a broken sled until I put my scratchers down.Poor guy looked like frosty when we got home!This was with the trail tank.With all the talk I looked and was able to space my radiator out towards the front of the sled about 1/2 to 3/4in.This not only opened up the area behind my radiator but sealed the fairing to the hood better to not allow air to escape forcing it through the radiator.The only reason I did all of this is because we all know a cooler engine makes more power.I do feel the mtx cooler will help most people as I trail ride without issues.

Interesting, any chance you could elaborate or take a photo of what you did to move the rad forward. Cheers.

x2

 

[tonesmoke]

I unbolted the mounts and used round stock I had in my junk draw with a washer on both sides.The washers are needed to spreed the stress on the mount on the frame and to bottom on the metal insert in the rubber bushing at the radiator.One thing I left out is I am using the OFT steering relocator.This allows the shroud around the radiator to move foward with no modifacation.You may just be able to cut the shroud if not using the steering relocator.Of course longer bolts are needed.

 

[mach9]

I unbolted the mounts and used round stock I had in my junk draw with a washer on both sides.The washers are needed to spreed the stress on the mount on the frame and to bottom on the metal insert in the rubber bushing at the radiator.One thing I left out is I am using the OFT steering relocator.This allows the shroud around the radiator to move foward with no modifacation.You may just be able to cut the shroud if not using the steering relocator.Of course longer bolts are needed.

That's great info... I had a look at mine today. I see how you could do that easy. That air behind the rad is trapped. I may try this mod. But not yet. Between the cooler t-stat and adding some holes in strategic places on the hood. Today I got it running @ between 157F to 170F on a regular basis. Very close to my target of under 160F . Not exactly sure if that will change as the outside temp goes up or down. It wasn't cold out tonight approx -4C.

 

[bagadonitz]

I unbolted the mounts and used round stock I had in my junk draw with a washer on both sides.The washers are needed to spreed the stress on the mount on the frame and to bottom on the metal insert in the rubber bushing at the radiator.One thing I left out is I am using the OFT steering relocator.This allows the shroud around the radiator to move foward with no modifacation.You may just be able to cut the shroud if not using the steering relocator.Of course longer bolts are needed.

Very interesting. A picture is worth a thousand words if you don't mind!

 

[tonesmoke]

Im going to try to post these pics.Here we go.

 

[GT03235]

I just cant seem to get into my mind how this would help? If you move the radiater forward like shown, the same amount of flow hits the rad. Please explain as i am missing some thing!!!!!
Trust me if it works i will do this as my sled over heats regular

Plus i understand the theory in ice scratchers helping our hyfaxs but helping to cool? do they throw that much onto the track?
We need a gopro cam mounted to watch this which would be awesome.

 

[tonesmoke]

If there is no space in back of the radiator it will hinder flow through the radiator.A radiator needs air flowing through it not bouncing off the front of it.With the trail tank installed the cooling fan frame was hitting the fuel tank.There was very little space.A factory tank may be alright but this mod can only help with air flow through the radiator.Think of old man Guss who needs a thermostat in his 1981 Ford.He places a piece of cardboard in front of his radiator.This hinders the air flow through the radiator and makes the engine run hotter even though his thermostat is stuck open.