[rob]

Guys, the check engine light on F7's means business. If that light comes on it means the coolant is over 176F and will soon boil. If it boils, the water pump can cavitate, and if the water pump cavitates, your engine will seize. When you see the light DON'T keep truckin like nothing is wrong, or you may end up on the wrong side of a towrope. This is a serious post and put it in your memory cells so that it doesn't happen to you!

 

[dave cat 7]

I HAVE RIDDEN MINE IN 34 DEG. WEATHER WITH TERRIBLE SNOW COVER AND NEVER HAD THE LIGHT COME ON OR HEADS GET REALLY HOT,
YOU MUST HAVE TO BE GRASS DRAGGIN FOR A HOUR TO OVERHEAT THESE!
THANKS FOR THE INFO ROB.
THIS MAY SAVE ANOTHER POST ON F-7 SIEZED UP

 

[czy42strokes]

Same here, I was running on hardpack for hours, no problems, but I would pull into loose snow as a precaution, just something I have always done to be safe, Thanks for the reminder rob, Some guys are new to this sport and don't have your/our mileage/experience..

 

[L8er]

I ran into the check engine light situation last week in Michigan. The temperature was around 40 and we HAD to ride on some snow/grass for about 1 and 1/2 miles to get to a trail head.

The light started flashing as soon as I hit the trail head, so I shut it down and waited 5-10 min. Started it back up and ran it on the snow packed trail and the light stayed off. I knew the light came on because of the high temp and no snow getting to the heat exchanger.

Good post Rob.

 

[Bulldog]

I had this happen to me last weekend. We were on Fence Lake in Northern Wisconsin Ice Fishing. The lake was glare Ice with a few patches of snow and we were using my F7 to haul out the tip ups and gear. It was fine when you could go fast out and back. (Maybe a 1/2 mile or so) After starting my sled and using the headlights (while it idled) to pull all 12 tip ups we headed for the cabin pulling a sled with all the gear and riding double. Half way back the check engine light started flashing. I tried to speed up but the sled got squirrly and dumped all our gear on the lake. By the time WE got to the cabin the light stopped flashing and stayed on. I shut the sled down and didnt ride it until the next day. Everything was fine and the light never came on again. I checked the manual and Rob is right. It flashes at 176 and stays on when the temp hits 200 degrees. If the temp light comes on you have serious problems! When the check engine light is flashing it means you are heating up and need to find some lubricant fast. :blink: :blink: :blink:
Bulldog

 

[BlackSaber7]

I have always tried to widen the hardpack trails I ride on :blink: so I can lubricate my slides and exchanger. This has always been something I have told my wife/girlfriends to do while riding. I thought it was common sense, but I guess you need to understand how things work before its common sense :wacko:


GREAT POST rob, many will benefit from this one.

 

[actionfigurejoe]

That light does mean business. Reverse flow cooling systems are more prone to pump cavitation than standard systems. When that pump cavitates, you can kiss the motor goodbye. I know that from my experiance with Chevrolet LT-1's. We did a couple of things to stave off pump cavitation on the early reverse coolant flow (modified) LT-1's. First we increased system pressure. Secondly, we incresed anti-freeze strength to 70/30. Both of these increased the boiling point. Proper system bleed was crucial. Chevy eventually solved the bugs with later additions of the motor. The Ford Taurus SHO had similar teething problems.

I know that other sled/motorcycle company(s) had messed with reverse flow systems on 2 stroke motors. They never piloted a sled with reverse flow systems because of these type of issues and the crucial nature of cooling a 2 stroke snowmobile. If Cat figured it out, more power to them. If not, revisions will be made.

 

[jay]

Originally posted by dave cat 7@Jan 7 2003, 10:45 AM
YOU MUST HAVE TO BE GRASS DRAGGIN FOR A HOUR TO OVERHEAT THESE!

Not necessarily, I had my light come on while running slow in about 10-12" of snow. I was towing my pipe drag groomer at the time, but the thing weighs no more than 30lbs, so that should not have been an issue. There was just no snow being "kicked-up" to any of the heat exchangers. Light came on in about 15 min. I stopped immediately and packed the running boards with snow in attempt to cool it down. I also checked to make sure that the coolant was not boiling. Took about 10 min to cool down, and then once again underway, a faster speed helped it to get some snow on the exchangers.

 

[rob]

correct! Going too slow in amy conditions is a good way to overheat. That was very true last year also with the zillions of problems with Poos overheating.

But the very worst thing you can do when the light starts blinking is to hold a steady 6000-6500rpm regardless of speed. That will cook the engine.

If the light comes on with a F7, best thing to do is stop and take a break.

 

[otterbob]

i was riding with my dad one day and my check engine light came on. we were just putting along a real rough section of trail so i stopped. he turned around to see what was goin on then all the sudden his temp light came on on his sled. (it was 32 degrees out) he rides an 02 zl 800ss efi. so its good to know that the same conditions affects other sleds.

 

[Davey_Boy]

There is a separate light from the low oil light and check engine light right? on mine there is, but on older sleds there were all in one.

the oil light flashes somtimes when i still have plenty of oil, at first i though it was the overheat light but its just low oil because they are separate lights.

 

[hvf7]

I had my light bilnking to day. 26 deg running on a road
with very little snow on it. I also have a short snow flap
with the rev . I shut it down for 10 min then got on a trail
with some snow on it and the light went away. We did 95
miles today. I now have 300 miles and NO prob.