Cr500 Thermostat Options?

[Pro-RmkBigsky]

I finally have my Cr500 snow bike put together and I have done a lot of reading on here and still am not totally certain on what to do as far as the things listed below. Your input would be appreciated.

-thermostat setups (I would like to run both radiators)
-engine cover (homemade or not)
-Pipewrap (yes or no)

If any of you guys ride around Southwest MT, I'd be interested to meet up and ride one day too!

Thanks in advance,
Dan

 

[summitboy]

Unfortunately the thermostat will not do much for up trail temps in a 2 rad system. In the deep a true closed stat like the Thermobob (does allow some leakage through bleed hole) may help to keep temps up, most likely will still run cooler than 130F in deep snow which is the same for the other brands. The best systems i have seen so far are 1 rad and a tunnel cooler with Tstat. Up trail temps are cool and deep pow temps are more consistant.

Id pass on the pipe wrap. Eng cover may help with the deep snow temps if below 130F. Ive never tried it. I think it would just be in the way. I like simple,clean and robust. Carb heat is your friend. Coolant flange type is the best.

 

[needpowder]

Running both radiaters you will either need two t-stats (spendy) or Y the two lines out of the head into one ( space issues, although I haven't tried it and it might be easier than I think). And then another Y or T to go into both radiaters. Personally, I deleted the left-hand radiator and went with the tunnel cooler using the right-hand radiator as a reservoir. I put an on off valve in the line coming out of the head to the right-hand radiator so I can turn it on as needed for trail cooling. Although I pretty much just leave it off and run just the tunnel cooler most of the time. My temps are awesome, from 130 to 140 pretty much all the time.

There are no aftermarket engine Strouds for the CR. You would have to make your own. I would suggest small ones at first if you go there. I just have a large skid plate and it seems to do the trick pretty well. I haven't been in 2 to 3 feet of bottomless fluff for any extended period of time so I don't know if I might end up needing covers in certain situations.

As far as the pipe wrap goes I'm not using any. The pipe sheds snow very well. My temps seem fine, and the pipe seems hot all the time even when it is often submerged in powder. You might want to consider wrapping the part that your pants are most likely to contact however. I have burned my left pant leg but not my right which was weird because I thought the right would be the one I burned more often. I'm just gonna fix my pants and slap some leather on the spots that contact.
Good luck.Enjoy your bike. I love mine!
Oh yeah, don't forget the carb heater. My bike started running like crap yesterday and I looked down and noticed that my valve was off on my carb heater. Turned it on and she ran awesome!

 

[needpowder]

Guess we were typing at the same time SB!

 

[kell8071]

Good luck.Enjoy your bike. I love mine!
Oh yeah, don't forget the carb heater. My bike started running like crap yesterday and I looked down and noticed that my valve was off on my carb heater. Turned it on and she ran awesome!

Can you elaborate on how it ran without the carb heat? I am trying to sort out if I am having intermittent carb icing or an ignition/jetting issue.


Thanks,
Kell

 

[summitboy]

Do u have carb heat ? If not im sure its most likely ur problem. Does it clear up after WOT ?

 

[needpowder]

Can you elaborate on how it ran without the carb heat? I am trying to sort out if I am having intermittent carb icing or an ignition/jetting issue.


Thanks,
Kell

It was sputtering on the mid and top end and felt sometimrs like my throttle stuck a little. Kinda like cruise control. That could be my imagination though with the throttle part. I think it was carb icing though because when i turned on my heater it went away.

 

[highflyernick]

I have a kx500. But they are the same animals. I ditched the left rad and am running a heat exchanger in the (frame) rails of the TS. Makes the mounting/hoses clean and easy to route.

I have the avid tstat/carb heater. My temps are 125 - 140 in 2ft of fresh consistently, long climbs, meadows etc. And I'm running no motor enclosures, and no pipe wrap. But my pipe has been ceramic coated. Which I feel was a good idea. Bit of a thermal barrier.

Personally, on long uphill pulls with my 500. Because of the slower speeds but you're on the gas hard, I couldn't keep it cool with the 2 rads. But as soon as I got the heat exchanger, problems solved!! Something to think about. Like I said mine is mounted up in the frame rails of the TS and it works fine. And looks clean. And doesn't get in the way of my 2 gas cans I mount.

 

[Pro-RmkBigsky]

Thank you for the help boys! I am aware of the heat a wide open 500 creates (it's my dune bike in the summer). I think I'll go single thermo-stat for tunnel cooler and put the non-deleted rad on an on/off valve.

One last question is what model sled did you pawn the heat exchanger off of? What fits nicely in the LT MH tunnel?

 

[summitboy]

Are you guys seeing heat in the deep at WOT ? My bike runs 90F tapped in the deep snow. The Pulse does run cooler though.

 

[kell8071]

It was sputtering on the mid and top end and felt sometimrs like my throttle stuck a little. Kinda like cruise control. That could be my imagination though with the throttle part. I think it was carb icing though because when i turned on my heater it went away.

That sounds familiar, I think my little KTM carb heater can't keep up with the deeper powder. It mainly started burbling in the upper 3/4 throttle and couldn't even get into wot if climbing in powder. Once back up to temp after running the road it I could pull through all of the carb circuits. Time to route a coolant line...


Sorry, not trying to hi-jack.


Kell

 

[needpowder]

Doesn't seem like there's a perfect cooler out there. I followed wwill's lead and used one off a cat 580. Then took it into mylers (radiater repaip shop in salt lake) and had them clock the outlets forward and reduce them to 5/8 for me. Took him 15 minutes while i waited. I'm sure you could send them in and have them done or find someone where you're at. Check out the cr 500 tunnel cooler thread. Good stuff there.

Picture of the stock cooler. I didn't take a pic of it modified but picture it with two outlets clocked forward. It's about 8 by 20"
I think.

 

[needpowder]

Are you guys seeing heat in the deep at WOT ? My bike runs 90F tapped in the deep snow. The Pulse does run cooler though.

This afternoon was my first time in the deep and light consistently. I was seeing closer to 100 going downhill and 120 to 130 going uphill. After struggling to pick my bike up after laying in the snow it would be about 70. That happened alot today!

 

[highflyernick]

Are you guys seeing heat in the deep at WOT ? My bike runs 90F tapped in the deep snow. The Pulse does run cooler though.

I'm consistently at 120 - 140 uphill, flat, or downhill (usually on the gas) in any sort of deep snow. My heat exchanger is like a foot long and fits in between/mounted to the bottom centre rails on the timbersled frame. Its basically right underneath my toolbox that mounts to the top rails. Stays at like 140 in heavier snow.

My heat exchanger is definitely smaller than most I've seen but seems to work great!

Im running the billet 40mm SC, seems to work decent. After getting new parts for it and removing a certain set of balls!! Cheers.

 

[summitboy]

The tunnel coolers really seem to be the ticket. I will see how the Yeti cooler works with one rad. I had Mylers make me a beefy right rad with a fitting or two in it. The cooling system will be ultra clean and simple. Id like to see 100-130F temps all day long. The 500 loves being cool in the deep.

 

[SEOINAGE]

The tunnel coolers really seem to be the ticket. I will see how the Yeti cooler works with one rad. I had Mylers make me a beefy right rad with a fitting or two in it. The cooling system will be ultra clean and simple. Id like to see 100-130F temps all day long. The 500 loves being cool in the deep.

Are you not using a thermostat then?

 

[Robbie]

If you are shutting off the by pass line on the Avid Bypass/carb heater be sure that you remove the sealant that blocks the weep holes in the thermostat. The thermostat will be slow to open without any coolant passing by it. Personally, I'd leave the bypass open all the time.

 

[needpowder]

OK. After today I'm changing my tune a little bit. Today was really deep,really light, and really cold. I could not hold temperatures at all. I dropped down to as low as 60° and had trouble getting back up above 80 or 90 in the deep snow. Not only that my bike ran like chit. The carb heater could not keep up. It just iced over and didn't stay warm enough. I had a wicked bog that would go away at the very top end but was there consistently when my temps were low and my carb was covered with snow and ice.
I have the neoprene carb Cover from avid. I'm gonna try it out this weekend when I can ride again. Though I don't see how I can possibly fit it over my carb--things are a bit tight in there! Hopefully I find a way. I'm also going to build some shrouds. Hopefully this helps.

 

[summitboy]

I will be using a Thermobob 3 in my system. Really doubt its needed but may help bring the deep snow temp up a hair. There are a few factors that can change the way the cooler setups will work. Configuration, motor tune, bypass size, bike model etc can change the temps you will see.

Robbie i was told by a stat mfg that the weep/bleed hole is for bleeding purposes only. If there is no hole then you could potentially get air under the stat not allowing it to open when it should until the air is removed. A lot of the stats I've seen allow coolant by with or without the hole. I know thermobob will do it either way but cautions the system may be hard to bleed.

 

[summitboy]

Also ensure you have enough air. Last year i had a outerwear's cover i made for my airbox top. I then also had a plate deflector on the back side of my airbox (keep the TS from shooting snow all over the filter) with the bottom of the airbox cut out all the way around. I thought i had a jetting issue. After scratching my head i removed the deflector and exposed the entire filter and removed the outerware cover. The bike instantly ran perfect ever since. The Pulse requires a lot of air !