Installing an extra radiator RS Viking

[mazellan]

Hi, I'm about to install an extra radiator on my RS Viking -07. I use it to groom ski trails and it overheats every now and then. I have searched the forum but I haven't found any clear instruction/picture of where to connect the second radiation. So this is like a sanity check before I start to cut hoses

My plan is to cut the hose labeled "To the tunnel" at the location of the red circle and daisy chain the new radiator from there. Does that sound ok?

/Maz

 

[YukonMP]

That would work for me. I know a fellow with an older model like yours and he had occassional overheating also. His solution was to put an over-ride switch on the fan because he felt it was coming on too late ... that worked too.

 

[mazellan]

Hi! Thank you for the tips! That was a much easier solution Anyway, I have already bought/gathered the material so I will go for the extra radiator solution. In the extreme case I had to stop 5-6 times, while grooming, to let it cool down. I even put snow/ice blocks on the radiator to cool it while driving but it still got overheated.

 

[hibshman25]

I think your logic would be fine. Exit hose from existing radiator feeds into second radiator and then exit from 2nd rad goes to tunnel cooler.

As mentioned above I 2nd the manual switch to activate the fan. If working the sled turn the fans on before you even start. This will prolong overheating even more.

 

[mazellan]

Thanks for the input! I will go for a two pole switch, (manually)ON - OFF - AUTO (controlled by the original fan). Then I can choose how I want it to operate. My feeling is that for 99% of the time it will be enough with just the extra radiator and the extra fan switched off. For the extreme case I can select ON, and some kind of intermediate way will be the AUTO Experience when grooming will show which mode that is the "best".

 

[christoph]

There's a thread on here that shows the 2nd radiator location and discusses this very issue. Grooming with VK Pro. Read up before you start cutting anything.

 

[christoph]

Here's the schematic which I'm sure you've already seen.

 

[Bearman]

Thanks for the input! I will go for a two pole switch, (manually)ON - OFF - AUTO (controlled by the original fan). Then I can choose how I want it to operate. My feeling is that for 99% of the time it will be enough with just the extra radiator and the extra fan switched off. For the extreme case I can select ON, and some kind of intermediate way will be the AUTO Experience when grooming will show which mode that is the "best".

Hey Mazellan,
If I may ask what kind of temperatures are you seeing for overheat? Have you verified what I am going to assume is a light telling you there is a problem?? I am new to the group but not trouble shooting and I have a great dislike for warning lights. Always nice to verify temperatures to really see what’s happening and documenting results is always beneficial. Always and I mean always start with the simplest thing first, if you do not, you will get burned. Not saying your conclusion is wrong, but that’s the beauty of this group, experience is going to point you in the right direction and a successful conclusion. If you can get actual temperatures you may be able to get some technical assistance from Yamaha, your dealer, or this group. Not sure how accessible you are but a nice little tool is a temperature gun, it shoots a beam of light at different locations and and takes temps, not 100 % accurate but it might save the day, mine cost me about $50:00 and is money well spent. Beats getting burnt trying to get into tight spots. Bearman

 

[mazellan]

Hi Bearman, thank you for the input. It is true that the easiest step is often overseen I have not verified the temperatures with any measurements. It is the warning light that I'm referring to when I say that it is running too hot. I actually bought a temperature gun, in the $50 range, less than a month ago. However, I'm not overly impressed with the accuracy of it. Maybe I just had "bad luck" with which "brand" I bought. I also have a device with thermo couples which I trust much more. Anyway, if I get some numbers for the temperature I have to know what is "too hot" and what is "ok". Getting those values from Yamaha is probably not possible for a random Joe like me(?). Unless the sensor for the warning light is broken/gives faulty values I think the only practical method is to trust the warning lamp.

Why do I trust the warning lamp? I think it acts reasonable. In most situations it does not turn on. It is at very specific conditions that it runs hot. Grooming ski trail when it is warm and the snow is wet. For the best result I have to go slow (10-15 km/h). At that slow speed and with wet snow "no" snow is thrown on the radiators in the tunnel. Wet snow typically packs infront of the blade and can make it tough to pull (pic of my homemade groomer). If the snow is dry, snow-dust will blow to the radiator in the tunnel even at low speed and no problem.

Also, you can buy an aftermarket kit at the local Yamaha dealer with a secondary radiator. That tells me that they are aware that there is a problem with over heating (for some particular use). It cost $1300 + installation. Thanks, but no thanks

The "best" solution would probably be to have a fan-cooled snowmobile (I guess that's why Yamaha still produces the vk540 with design from the early 1980 ). But I appreciate the comfort and not having to smell those 2t-fumes more

 

[YukonMP]

Thanks for the picture.

Whenever I have seen the actual numbers that Yamaha uses for temp warnings they are very conservative. Also, Water Wetter, or it's equivalent does help a little. My MP used to throw the warning light ocassionally but not after I added WW.

 

[Bearman]

Hi Bearman, thank you for the input. It is true that the easiest step is often overseen I have not verified the temperatures with any measurements. It is the warning light that I'm referring to when I say that it is running too hot. I actually bought a temperature gun, in the $50 range, less than a month ago. However, I'm not overly impressed with the accuracy of it. Maybe I just had "bad luck" with which "brand" I bought. I also have a device with thermo couples which I trust much more. Anyway, if I get some numbers for the temperature I have to know what is "too hot" and what is "ok". Getting those values from Yamaha is probably not possible for a random Joe like me(?). Unless the sensor for the warning light is broken/gives faulty values I think the only practical method is to trust the warning lamp.
Why do I trust the warning lamp? I think it acts reasonable. In most situations it does not turn on. It is at very specific conditions that it runs hot. Grooming ski trail when it is warm and the snow is wet. For the best result I have to go slow (10-15 km/h). At that slow speed and with wet snow "no" snow is thrown on the radiators in the tunnel. Wet snow typically packs infront of the blade and can make it tough to pull (pic of my homemade groomer). If the snow is dry, snow-dust will blow to the radiator in the tunnel even at low speed and no problem.

Also, you can buy an aftermarket kit at the local Yamaha dealer with a secondary radiator. That tells me that they are aware that there is a problem with over heating (for some particular use). It cost $1300 + installation. Thanks, but no thanks

The "best" solution would probably be to have a fan-cooled snowmobile (I guess that's why Yamaha still produces the vk540 with design from the early 1980 ). But I appreciate the comfort and not having to smell those 2t-fumes more

View attachment 157617

Hi Bearman, thank you for the input. It is true that the easiest step is often overseen I have not verified the temperatures with any measurements. It is the warning light that I'm referring to when I say that it is running too hot. I actually bought a temperature gun, in the $50 range, less than a month ago. However, I'm not overly impressed with the accuracy of it. Maybe I just had "bad luck" with which "brand" I bought. I also have a device with thermo couples which I trust much more. Anyway, if I get some numbers for the temperature I have to know what is "too hot" and what is "ok". Getting those values from Yamaha is probably not possible for a random Joe like me(?). Unless the sensor for the warning light is broken/gives faulty values I think the only practical method is to trust the warning lamp.

Why do I trust the warning lamp? I think it acts reasonable. In most situations it does not turn on. It is at very specific conditions that it runs hot. Grooming ski trail when it is warm and the snow is wet. For the best result I have to go slow (10-15 km/h). At that slow speed and with wet snow "no" snow is thrown on the radiators in the tunnel. Wet snow typically packs infront of the blade and can make it tough to pull (pic of my homemade groomer). If the snow is dry, snow-dust will blow to the radiator in the tunnel even at low speed and no problem.

Also, you can buy an aftermarket kit at the local Yamaha dealer with a secondary radiator. That tells me that they are aware that there is a problem with over heating (for some particular use). It cost $1300 + installation. Thanks, but no thanks

The "best" solution would probably be to have a fan-cooled snowmobile (I guess that's why Yamaha still produces the vk540 with design from the early 1980 ). But I appreciate the comfort and not having to smell those 2t-fumes more

View attachment 157617

Hi Mazellan,
First off, nice looking groomer, looks fairly simple and compact.
Sounds like you have some good tooling on hand so you are set there.
I am not sure if you have a service manual but that will tell you what temp the thermostat opens and also, cooling system capacity, and the temperature your temp light sender, sends a signal to the light, may be worth checking this just to be sure they are telling you the right story. Possibly a good job for your thermocouples to verify the light?
As others have suggested having the ability to run the fan with a manual switch will give you better control.
Instead of going the additional rad route I am wandering if you can add system capacity with another heat exchanger or even a small automotive heater core, or loop of coolant hose, this adds more coolant to the system and might just be enough to eliminate your heating problem. I am not at all familiar with Sweden’s parts availability so maybe this is not an option.
Please let us know how you proceed and what your results are. Cheers. Bearman

 

[mazellan]

Hi, and thank again for the tips and input. I don't have the service manual just the owners manual. In that it only says that the engine will shut down if you are idling for more than 3 minutes and the engine temp reaches 100C. I will update this post when I have some results. Unfortunately there is too little snow right now and the ice is too thin to groom the ski trail, 5-10 cm (2-4") only :/

I like the model of the groomer. You can set it so its s very easy to pull, just raise the levers to the wheels that are connected with chains to the "level bar". This rises the blade so it is only the "rolling resistance" of the wheels that you have to overcome. It also have an automatic control of the pull force. If the load on the blade increases the load level bar will increase the height and thereby reduce the load. Not my invention Old tractor manufacturer Ferguson invented this system.

 

[Bearman]

Hi, and thank again for the tips and input. I don't have the service manual just the owners manual. In that it only says that the engine will shut down if you are idling for more than 3 minutes and the engine temp reaches 100C. I will update this post when I have some results. Unfortunately there is too little snow right now and the ice is too thin to groom the ski trail, 5-10 cm (2-4") only :/

I like the model of the groomer. You can set it so its s very easy to pull, just raise the levers to the wheels that are connected with chains to the "level bar". This rises the blade so it is only the "rolling resistance" of the wheels that you have to overcome. It also have an automatic control of the pull force. If the load on the blade increases the load level bar will increase the height and thereby reduce the load. Not my invention Old tractor manufacturer Ferguson invented this system.

Hi Mazellan, interesting about Ferguson, first thing I ever drove as my grandfather used one on his farm and taught me to drive.
I am just going through the process of getting a service manual for my 2021 VK Viking Pro, through the VIP membership in this group. I believe it’s $15:00 which is well worth it ,but my manual is not yet available, too new I guess.
I understand about the low snow, nothing to be done about that, we are lucky as we have 2 feet on the ground we’re I live.
Interesting your sled shuts down at idle when too hot, I guess the thought is to prevent a total cooking of the engine, not really in favour of shutting down a hot engine but that can be overridden by staying above idle, in your case with a working sled with load and a clutch to contend with that’s not going to be an option.
(I believe low oil pressure causes shutdown too but that’s another matter.)
Thanks for sharing your information.
Bearman

 

[bjowett]

Don't forget to tweak your coolant/H2O ratio. A better coolant degas tank would likely help, too.

https://hellafunctional.com/?p=629

 

[Bearman]

Hey Brian,
I agree, proper mixtures will aid cooling and extra expansion tank or bigger tank will add system capacity and lower excess coolant temps.
Thanks for your feedback
Bearman