01-16-2002, 02:54 AM
My buddy picked up a 1999 xlt 600. The pto piston burnt out.
The carb was very clean clean. The base Gasket had a small amount of *White silicone all aound it. Is this silicone normal for polaris base gaskets? I'm not too familier with Polaris, but it seems like this engine has been taken apart before and the gaskets haven't been changed. Info Please.
01-16-2002, 04:31 AM
The gasket comes like that from the factory.
01-16-2002, 06:43 AM
First of all, is it really a '98? *There was no XLT in 1989. *If it was just the pto base side, then I would say no. *I've never heard of white silicone in engine assembly. *Maybe I'm wrong. *When you put it back together use 1104 gasket bonder, or I use this spray gasket from either 3M or someone like that. *It is about $8 a can, but never had a problem. *It comes in a brownish can. *Make sure you scrape all the silicone off and clean the surfaces. *Spray each side of the gasket a few times after letting each application dry a bit. *This choice is a little less messy than the 1104.
01-16-2002, 07:46 AM
If you aren't able to find an answer as to why that piston let go internally, I'd be really suspicious of the PTO crank seal.
In your shoes, I would reassemble the motor, get it running, and spray some WD-40 around the area of the seal, around the base of the carb, and the base gasket area. *With the engine running and the WD-40 being sprayed, you are listening for an increase in engine RPM. It won't be a problem hearing it. When you find a leak using this process, rpm will
pick up enough to be easily noticable. If the machine passes this test, I'd take it out for a ride and keep an eye on that plug. That piston failed for a reason, it needs to be found. Good luck.
01-16-2002, 09:11 AM
PTO side piston? sounds like a bad seal.
As far as the base gasket goes, OEM base gaskets for polaris have a small layer of silicone on the gasket material. It is only on one side and it has to be installed towards the cylinder - not the base.
Check for the failure mode on the piston, was it overheat, lack of lubrication, excessive piston clearance, etc. Analyzing the piston, cylinder and head will tell you what the failure mode was.
01-16-2002, 09:12 AM
By base gasket do you mean the one between the carb and the block? *There shouldn't be any sealant around it. *If that gasket was leaking it should have been replaced, because once it leaks that cylinder will run lean do to the increase in air coming in.
01-16-2002, 07:58 PM
Allways use new gaskets when you reassemble an engine and donot substitute silicoln or engine sealer in place of the cylinder base gasket as you will change the port timing of the motor the only place you use an engine sealer is when you split the crankcase to take the crank out then you will need a crankcase sealer polaris shop should have this on hand do not use rtv in place of this as it will attack the aluminum case and arrode away at it wich will make the case useless.
01-16-2002, 08:03 PM
Yes there was an XLT in 98and 99 as MY family owned a Polaris dealership and we sold them the special was in the aggressive body and it had the flatslide racked carbs on it and the limmited was in the evolved body with the smaller carbs and more touring options.
01-16-2002, 08:45 PM
Thanks for the info. I found out today from polaris that there is a white sealant on the factory gaskets.
01-17-2002, 03:08 PM
If there is a seal on the one side, the only added security I would do would be to use the spray on the one side without the seal. *I used the stuff on both sides of my Indy 650 base gaskets since they were the same on both sides. *As SNORAT suggested, use something like 1104 bond or dealer equivelent only to put the case back together. *My only suggestion for base gakets was to spray the side without the seal for a little added base gasket strength. *Besides, a little spray tac isn't going to change your port timing. *If it does, it can only help the XLT. * http://www.snowmobileworld.com/forums/iB_html/non-cgi/emoticons/tounge.gif