I have a 97 cougar thing has been great for the four years i have owned it until this year.Now i am thinking matches to the gas tank.I have put two new jugs and pistons in this last week thought they may have burned dew to 5000 miles on the sled and some warm weather.but now i know that is not it.just burned my third piston in two weeks with not even fifty miles on it.checked for lack of oil wasn't that thought it may be leaking anti freeze and my temp gauge wasn't working.( but the temp gauge works) this is the only thing i can think of.i added picks this year to it and as my track stretched out the picks ripped into my heat exchangers on the front of the tunnel they do not leak but is it possible that they could block the passage way of the coolant with out leaking.I am 26 and know a little about sleds but i need serious help with this one.I have bleed green with 69 panthers old el tigre i grew up on never owned anything else and do not want to jump ship but i am getting pi$$ed off with $900 dollars invested in an old sled just in the last two weeks and 1500 in it for the season.please help!!( or talk me into a firecat))!!!!!!!!!!!!!!! :( :( :(

When you say "burned down", are you talking about melted domes, especially towards the exhaust port? If so, you are porobably running lean. It would help if you gave us more info. Tell us what the pistons look like. Check everything that can make it run lean: fuel pump diaphragm, dirty carbs, air leak (pressure test your crankcase), etc. If you had a lack of oil, you should have major scuffing on the sides of pistons without a lot of dome damage. Give us more info so we can help better!

pistons black over the whole top and scard and also scaring the jug on the exhaust side.rings won't move there melted to the piston pretty much! i have sprayed ethyer around the carbs while running to check for air leaks and have come across none.did have a friend clean the carbs this year.don't know anything about them.how would i tell if it was leaned out.

You should look at the carbs, could very well be junk in a jet or if the guy who went through them moved the clip on the needle. There is a problem with that engine that caused it to fail the first time and you have not fixed the cause yet only the result of the cause. !!!

I agree, you need to find the cause of the first burn down. If everything was fine until this year, and the carbs were just gone over, I'd start there. It is very possible that something didn't get put back together or re-set correctly. Or maybe even something got bumped, pulled, etc when the carbs were removed and re-installed (been there, done that). I'm not an expert at reading pistons (my guess is lack of oil) but by what you describe, someone will be able to point you in a direction.

Be patient and good luck.

Are both pistos the same? Or is this isolated to one cylinder?

How much oil is it using?

What has the engine temp guage been doing? Normal or?

Definetly get the carbs checked since this is the only thind you changed since last year and check the carb boots as well. Check the timing, do or get a leakdown test done and if you are really nervous get the crank checked to make sure it is true and in phase, a picture of the piston would help.

Yeah my opignion is that it might be carbs as well. When you rebuild it. If you take care to seal jugs well and everything is tight. I would think it is caburation. Timing usually doesn't change unless it is physicly changed.. I would also check your crankcase for a leak. Usually if you have a leak you will notice.. The machine will idle higher than usual, or idle erraticly. And of course it will run hotter than usual.
If you rebuild it again. It would be worth it to bring it to a dealer and get them to synchronize and tune your carbs. Also. When you run it for the first time. They recommend a break in period. My manual for my 90 cougar recommends running a 50:1 mix for the first tank and not pushing the engine too hard until it breaks in. If you do run it after rebuilding it. Make sure to keep an eye on your spark plugs. eally they should be anywhere from brown to a grey. Brown being on the richer side...grey being on the lean side. If the tips are white it's definetly a lean condition. Judging from your piston description.

Hope that helps

Originally posted by 97cougar@Mar 3 2003, 03:38 PM
pistons black over the whole top and scard and also scaring the jug on the exhaust side.rings won't move there melted to the piston pretty much! i have sprayed ethyer around the carbs while running to check for air leaks and have come across none.did have a friend clean the carbs this year.don't know anything about them.how would i tell if it was leaned out.
If the pistons are black all over with no edges burned away, it's probably not lean. Did you have the engine out of the machine when it was rebuilt? If so, did you bleed the oil injection pump after connecting the line? Was the cooling system properly bled of air? Did you check the crankshaft bearings? More info please.

Cougars are notorious for being hard on pistons, but to have it go bad so soon after rebuilding it says that there is something else happening. Either you didn't fix the problem, or you created a new problem during reassembly.
Did the pistons look the same both times when they went?
Did you take the bottom end apart and inspect it?
Do you have access to a digital camera? It would help alot to see some pics.

I appreciate all the info.I am going to try to get some pictures on digital camera so you guys can get a better look. I am putting the sled up for the winter due to funds but i will be ripping the engine apart to find this problem.i will definetely keep everyone posted.thank you very much.I'am going to start with the carbs and go from there.although i'am curious if i had a leak in the crank case would i be able to visually see spillage?? i will also bleed my oil and heat exchangers to see what the hell has broke me money wise for this year.