I have a 98 T-Cat 1000 with a 136” track. On the last ride of the season I think it “blew” up. My Brother-In-Law was riding it in low hard packed snow conditions. He rode it all day and then shut it down to load it on the trailer, it started and we loaded it. The next day we tried to start it and you can pull the rope about 1’, it will roll over twice and then the rope gets so tight that I think it’s going to break. It does this every time you pull on it. What’s the problem?
The sled has 5000 miles on it and is bone stock with the exception of reeds.
My next question is what should I do to the sled for some recreational drag racing? I love the sled’s power, but like every T-Cat owner I want more!

I have seen this happen before. There is two gears that mesh on each other, one on the crank and one on the balance shaft.

On a good engine when you pull it over with the key off, you can hear the "rattle" from the gear lash.
I have seen them chip or break a tooth of the gears from a backfire or sudden engine stop.
I think you may have broke a tooth off and it is getting lodged in the gear stopping it from rotating.

I am in Monroe, 35 miles south of Detroit.
I have been a snowmobile mechanic for over 20 years.
I could take a look at it for you ?????
Mike

Sounds about right. You could pop the heads off and check for scoring on the pistons/cylinder wall too (over heated, water pump failure, sucked some snow ect..). Check the easy stuff first. Probably none of the fixes will be cheap.

I'm sure it won't be cheap to repair, that's why I figure I may as well do some fun stuff to it while I'm in there. I think I'm going to get with Ron about this; I hear he builds some STRONG engines. Thanks for the offer Snow800, but it's not convenient for me to get down there.

What does it do when you turn it over by turning the primary clutch?
Turn it one direction and then the other, sounds too simple, but maybe the recoil is screwed up?

Sure it just didn't load up with fuel? if the cylinders and case filled up with fuel you would have that problem also.

I don't know what it will do when I try the primary clutch; I'll try that first. I'm also going to look for fuel in the cylinders.

One more thing. My B-I-L said that he had to pull on it 6~8 times to get it started after our last stop for a break. Our last stop was only about 15 min from the end of the ride. Does that help any of you guys with your site-unseen troubleshooting? Obviously the engine was still warm and it's usually only a 1~2 pull restart.

I re-read your 1st post. Here's another guess. Overheated it, blown inner o-ring on at least one head and the coolant is in the cylinder. If it is an outter o-ring it will pressurize the coolant and it will blow out of the coolant bottle. If it did overheat, you need to lap all of the heads because they are probably warped. Stock ZRT's and Thundercats all run too hot in stock form. So if you ran it even a few miles in low snow conditions, you got it way too hot and took out an o-ring. If a lot of coolant got into your cylinder it will take out the piston and score the cylinder too. You may be able to pull the pipes and check each cylinder with a flashlight through the exhaust. One cylinder may be scored. That'll be your bad cylinder. Also, you may notice one plug seems "wet" while the other 2 are normal looking. That too will let you know which head overheated first.

That's my guess. Liquid in the cylinder. Might be fuel or coolant. If your BIL didn't shut the fuel off before towing it home....
You could pull the plugs and see if it pulls over then, or it might be a balance shaft gear problem that the earlier poster said.

Did you dig into this yet? What did you find?

I haven't done anything with it yet. I have the talking part out of the way, so now it's time to get to work or get rid of it. I probably won't open it up until this Fall.