1973 polaris tx 440 piston question - Snowmobile Forum: Your #1 Snowmobile Forum

srt4guy · 04-01-2008, 08:45 PM

o.k. so i have a bad piston and i took it out now i need a replacement and i have questions. i was told that the motor had been bored out but i don't know
question #1
i measured the diameter of the piston and got 2.660" and the wiseco web page lists the application at 67.75mm bore which is2.667" in diameter, is the .007" the size of the cylinder or the piston?

question #2, does this mean that i in fact have a standard bore piston

question #3 can i run one factory piston in one side and a wiseco in the other, not looking for super high proformance here just a sled to tool around on.

any and all help is appreciated.
Tim

**RJ Gleason** · 04-02-2008, 05:15 AM

You can, but the weight difference of the two pistons will cause excessive vibration.
Better that you have a matched pair for longer bearing life.

Actually, the TX was not until 74, build year was 73.
2.667 is the cylinder bore, and the stroke is 2.362, making the engine a 433.
It would appear the the engine bore is stock then.

srt4guy · 04-02-2008, 03:12 PM

actually the build date is , Aug 72 and it has tx written all over it, factory decals and all, wierd, anyway the motor in it is an EC44-ps-02 and on ebay there is a set of jugs and pistons with the number EC44-PQ-04 will this work for me? or is there someone out there with a factory piston that wants to sell?
Tim

**RJ Gleason** · 04-03-2008, 08:11 AM

The PQ has different porting and uses matching pistons.