carls 910 seems thermostate??

[pharotek]

I have a 910 with twin slp pipes, that i put into a 01 600 edge chassie. I am haveing some temp issue's. On trail with ~1" loose snow it runs hot 170-180, if i get into deep snow it will cool down too 140-150, once out of deep back to high temps. At idle it will climb 200+. I have checked for air and will put back on tilt trailer again to check for more trapped air.

I also have done/current setup:
Domes have 6cc (were 50cc now 56cc) removed to lower Compression for pump gas and elevation
540N main jets
Needle on #3 mark
Air screw 1.75 turns out

When i bought the motor online i noticed the thermostate was missing did carls have ppl run them without one? My though was it could be circulating to fast and not cooling correctly without one?? Last question, the "cold line" on coolant bottle should that be level with the top of the head cover? If i recall correctly on my 600 it was and with this being little taller motor it sits below, so this is were i could be collecting air????

I have also pinched off some not all way, line that allows coolant to flow driectly back into the return line some. this did seem to lower it some more. Was thinking it may be flowing to much coolant back thru to motor and not the system to cool off??


Thanks in-advance for any input!!

 

[pharotek]

looking around at images an waiting for image from someone else maybe.... I see other or sleds with 03 the bottom fitting coolant line does not go back to the coolant bottle and see to route to another area.. This may be my issue for on the 01 600 it goes back to the coolant bottle...???

 

[sled_guy]

My 910 is in an 02 RMK chassis. I have a U-cooler in mine, eliminated the running board coolers and pulled the cooler from in front of the track.

I ran without the thermostat originally, but the dang thing only ever ran around 90-100 degrees so I ended up putting the thermostat back in along with the bypass line and now it holds at 118-122 with the scratchers down on a groomed trail... again, I have a U-cooler.

Do you have the thermostat in it? If so, is it working right. I'd figure out how to stop the motor recirculation... I'm guessing that is your default loop and you aren't getting good circulation back through the tunnel coolers.

sled_guy

 

[pharotek]

I am thinking same thing now too Sled_guy after images i have seen. I do not have a thermostate in it right now. I'm going to try and pickone up. Also i'm look up your seld and see what the U-cooler looks like I am assuming this and the coolant bottle level are the roots of my issue. Anymore info Poeple may have is welcomed!

ALso i do not have running board cooler this sled has the forward tunnel cooler then the 2 rails down the tunnel alined withthe track windows.

 

[BB454]

So you have a XC chasssis, I don't think you have enough cooler for the 910. Try the thermostat first.
You can add a RMK rear cooler that fits just in front of the rear bumper on the bottom of the tunnel. You will need to get creative with the hoses from the 2 wear strip coolers.

 

[pharotek]

I saw that when i looked up sled_guys sled and saw the cooler in the rear. I'm look for one now, hose shouldn't be an issue since in the back their is a rubber hose that links the 2 coolers, have an extend track so that should help! What thermostat is getting put in these engine just one from an 02-05 800rmk?

 

[BILTIT]

I assume it has the bypass loop similar to an rmk?

You want this one.

 

[pharotek]

i got the thermostate the other day and worked on installing before work. Will get air out and test out the changes i made.

1. Added thermostat (seemed to just fit had to push down on cap some to get it in..?)
2. i moved the coolant bottle 2" toward the exhaust and lifted it so the cold line is level with the head cover's top surface.
3. i also routed the line from engine out to brake, so it was in a lower postion then the bypass hose.

Hope these help if not i do have a rear cooler on way from a RMK.

@Biltit, I do not have the bypass line like the 02+RMK which go down to the forward tunnel cooler unit. Mine is of an 01 xc 600 sp, which the line does this down and up shape then to top of coolant bottle. If i'm still not cooler i'm install the rear RMK cooler. If that does not help then i'm re-route the bypass line...um...somewere so the coolant drops in temp some before going back to motor or maybe just block that bypass fitting off competely?????

 

[pharotek]

it seemed to have dropped around 15°F.... I contacted carls they want me to remove the bypass line fully and cap both sides off and remove the thermostate for now. I'm try this and hope to the snow gods it all works.....

 

[pharotek]

bypass removed and in 2-3" loose snow around 145°F and on packed trail went up to ~165°F. I went back into loose snow and it came back down to 145°F after about .5miles. This seems to be a big improvment, also it was 40°F out that day. I had the rear RMK cooler installed and sadly in my area we are out of snow..... I am takeing the sled north with me this weekend and will see what happens..... If i get it to be ~145°F is that safe temp think for the motor? When i was told 120°F, i though that was really low for groomed trails??

 

[sled_guy]

I rode on Tuesday and watched mine really close. Mine is in an 02 RMK, with a full length U-cooler and no other coolers. I have the small head bypass installed and a stock thermostat. The thermostat opens at 120.

In deep powder, pulling hard it runs at 122 degrees all the time. Before I installed the thermostat it would run at about 90 degrees in this situation.

On the groomed trail, with a little bit of lose snow, with scratchers down it runs at 135-140 degrees. That is at a decent pace. If I slow down it will climb and keep climbing to 160 degrees at which point I either bail off into the lose stuff or drag a foot for a couple of minutes to cool it back down. I run the 159x2.4 track and it doesn't throw snow on the cooler very well at slower trail speeds.

Towing a broken 2008 Dragon 800 out on the groomed trail, lose snow, scratchers down, it held right at 150 degrees most of the time if I kept the pace up a little bit.

145 degrees will be fine for your motor, I'm betting in deep powder it will drop below that though.

sled_guy

 

[pharotek]

that is good info to read, based of that and my last ride, i think i should finally be set, also i do not have scratchers and should be able to pick up set this weekend somewhere. I'll report back on how i made out. Thanks again for your time to discusse my issue!

I really shoul dpost on here my build and pictures i have a whole thread on Snowmobile Fantiacs. here is link if you don't mind going there. http://www.snowmobilefanatics.com/forum/topic/130231-my-910-mod-sled

 

[pharotek]

I rode the sled this weekend with the rear cooler now installed. I was getting temp reading of ~110°F on my koso digital read out(which is installed in head cover next to thermostate housing OEM them sensor) gauge. I rode about 40miles and it held that temp, however here is this issue now...

Temp reads ~110 all the time, the over temp light kicks on every once's and a while. It also is retarding the motor, if i back off throttle for bit to 20ishmph or wheelie off bump it will go out get back on it it pops back up. Remind you the gauge i installed still reads 110. we rode for ~20miles and made a stop, went to start sled up and the recoil would not grab the cup. Seemed the dog was stuck inside the pulley. I think this happens if the recoil pulley gets too hot and it causes the dog to stick inside the recoil pulley? Once the motor cooled down it would grab the cup every time. I also noticed when the recoil would not grab and i did get it to start the Temp gauge would read upper 170's, then within 30sec drop down to ~120°F.

I got home after the weekend and found the resivior bottle had lots pressure on it still(after 4hr drive on trailer) and when i opened it it was full to the brim with coolant. I though maybe issue is due to blocking bypass off. I went to check bypass fitting to see if it had anything to due with how i blocked it off, i don't think it does. However i did notice when i removed the thermostate housing there was space in-bewteen the head and head cover that was not filled with coolant (as in no coolant came pooring out when i removed the thermostate housing). I am thinking it was air-locked and not flowing out around the cylinders correctly..???? I'm try to get pictures posted of the system once i get home in the am.

 

[BILTIT]

Sounds like an air lock.

 

[sled_guy]

Ok, trace in words for us what your coolant system/path is.

All but the temp light coming on sounds pretty normal to how mine runs... cool as a can be until I stop it... heats up while turned off, cools right back down after starting. Not surprising, the motor has no flow in it so it transfers all the heat to the fluid in it.

Was the light on solid or was it flashing?

sled_guy

 

[pharotek]

top Engine out->Brake caliaper->Tunnel cooler->Rear cooler->back to tunnel cooler->forward cooler->coolant bottle->engine in

The bypass if inplace would go from lower engine out-> top of coolant bottle

temp light would start out blinking and if i did not left off or "hit bump/wheelie" it would go to solid, but mostly just blinked.

i have the coolant bottle's cold line just above the top surface of the head cover aswell.

 

[sled_guy]

Blinking temp light is DET, not heat.

So is your thermostat dead heading then? You might want to drill a couple of holes in it so that water can get through it, dead heading the pump isn't optimum.

sled_guy

 

[pharotek]

i don't have a thermostat in-place........ Could it be from the rear cooler, maybe add the bypass line in again?

 

[pharotek]

So i was out on the lake this weekend and have the coolant all bleed out, and it is holding a good level in the coolant bottle. I am now still getting the Temp light to blink and it goes away once i return to idleor drop RPMs below 6k. I was told the DET is a microphone that picks up pinging noise from the motor. Though it could be from the sled being lean?????? Pulled the plugs and they had a yellow tint to them. Put in new plugs and this is after 3x500' pulls.

View attachment 201279 they are yellow in color slightly

i am running 550N main jets now with needle on #3.......... could it be this lean still and causing engine to knock creating noise and the DET is picking it up?

 

[sled_guy]

What mixture of av or race gas are you running?

Lean in and of itself won't cause detonation although richening can mask detonation (Yeah, that sounds weird). I've seen DET sensors pick up things like exhaust springs vibrating and such.

Easy test is to up your av gas mixture and see if the DET goes away. If it doesn't then you can start looking at things like exhaust springs and such that might be setting off the DET (just squirt a line of silicon on them to stop their vibration).

sled_guy