Over heating

[fast shee]

This weekends race was a wet and muddy xc race. 45 minute race in thick mud and water. The bike was overheating and started pushing the coolant into and then out of the overflow bottle. I did put a plastic curtain in ft of the engine and electrical to keep it dry. One other thing is I had the number plate mounted on the ft bumper. Other than removing the Plate from the bumper, what else can I do to get this thing to run cooler?

[THARNESS]

Go to your locak hardware store and buy some window screen. Zip tie or duct tape it in place wherever you need a shield. It will keep the mud and heavy splashes of water out but will still allow some air to pass through. Anything you can do to keep the radiator free af mud and keep some air flowing thru it.

[fomospede]

buy a pyrometer and see where the heat is generating, cvt or motor
we painted are numbers into the xfr screen
im wondering if your overall gear ratio is to much and in the muck drove your cvt temp thru the roof
also we clean are radiator all the time inspecting and straightening the fins fo max aiflow
if you have the stock black mesh in front of radiator ditch it it slows the airflow by half

[tyler70t]

Check the fins on the impellor to make sure they are all still there. Also might be a bad radiator cap.

[fast shee]

The bike is a stock engine 90 but the cvt temps would make sense because i reviewed the video of the race and saw that my son was riding with his foot on the rear brake pedal for most of the race so i will have to adjust that. The black screen is still in front of the rad so i will remove that. Thought about painting the numbers on the ft bumper screen also. I will also have to do a compression test to see if there is any damage inside the engine. What kind of compression on a stock 90 liquid should i see? Been thinking of changine to a mildly ported cylinder and clutching for a better holeshot. Any suggestions?

[fomospede]

im unsure about compression
im wondering what size rear tires you run and sprocket ratio
higher stall equals less spring life and more heat
correct drive ratio
check for parasitic losses

[fast shee]

I am running 20/32 gearing with 18x8x8 quad cross out back. Thinking it must be stock springs in the clutches because i have not touched it and the bike was new stock from hot quads to the previous owner. I have a hetrick gen 2 pipe to put on it and going to try to find a good used 28 keihin pe for it.

[fomospede]

try a 18 up front
bet you loose the cvt temp and come off the line good

[fast shee]

18 on the ft sounds like a lot? Is that what seems to work better on a stock setup? I do plan on installing a inline temp gauge in the lower rad hose to monitor the temps. I do still have the 18" snow hogs on wheels if that will make a difference on the cvt load.

[FISH ON!]

Originally posted by fast shee
18 on the ft sounds like a lot? Is that what seems to work better on a stock setup? I do plan on installing a inline temp gauge in the lower rad hose to monitor the temps. I do still have the 18" snow hogs on wheels if that will make a difference on the cvt load.


Put your inline temp gauge on the upper return hose so you can get a more accurate reading of the cylinder temp. My $ 0.02 worth.

[fomospede]

Originally posted by fast shee
18 on the ft sounds like a lot? Is that what seems to work better on a stock setup? I do plan on installing a inline temp gauge in the lower rad hose to monitor the temps. I do still have the 18" snow hogs on wheels if that will make a difference on the cvt load.

the 18 will slow it down on top but will have more acceleration out of every corner
also gearing for top end speed you need to time how long it takes to go from point a to b
to much gear equals longer times and more cvt heat and prematurely dished variators
dial it in ( a never ending process!)