80' Trailfire 440 rebuild! Advice and opinons welcome

[JDT]

Matt DR... I see some pretty ugly ports on your cylinders.

I would spend some time cleaning and polishing them up before final assembly.

[deerehunting]

I just got this other piston that's P/N 09-688. I didn't know about it until last week. Can you take some measurements on the original piston to compare to?

what measurements would you like me to take? That piston does look more like oem.

[deerehunting]

yeah todd I still have a lot to clean before assembly I don't even have the base gasket off yet. lol im kinda bouncing all over the place on this sled.

[Matt]

I just got this other piston that's P/N 09-688. I didn't know about it until last week. Can you take some measurements on the original piston to compare to?

what measurements would you like me to take? That piston does look more like oem.

Overall height, top edge to 1st ring, top edge to center of center pin, width of skirts

[nick80lf]

I just got this other piston that's P/N 09-688. I didn't know about it until last week. Can you take some measurements on the original piston to compare to?

Very interesting......I see that's listed for early Cats.

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[Matt]

This does look a lot like the original piston you posted the photo of:

https://drive.google.com/file/d/0Byn46X ... ljaXc/view

[deerehunting]

Tmartin just got back with me on the gpi piston that works, it is the listing for the early Kawasaki arctic cats also like the 09-688 so I'm gonna assume those are right, and matt I'll get those measurements for you.

[deerehunting]

Matt I would say that piston in the pic Is same definitely a whole lot closer than the other one.

[deerehunting]

I'll get some quick measurements when I get home

[deerehunting]

my caliper is in my garage and it is a blizzard out so here are the measurement with a tape measure not precise but close enough, from top edge of piston to top of first ring groove is 5/32", from top edge of piston to center of wrist pin is 1-7/32" , total height from top edge of piston to bottom of the skirt is 2-19/32" exhaust skirt width is 2-3/32" intake skirt width is 2-1/4".

[Matt]

The only thing that does not seem to match up is the skirts. I'm coming up with 2.06" (1/16) on the intake and 2.25 (1/4) on the exhaust, unless I've got intake/exhaust backwards. The ring locating pins are on the 2.06 side.

[deerehunting]

Yeah the locating pins are on the same side the smaller skirt. I'm willing to bet it's right , I don't think I'm gonna try this piston I have, I think I 'm gonna order a 09-688 and try it out.

[Matt]

I only have one here, but I'll trade it for your other piston(s) if you want.

[deerehunting]

We could do that I have the one piston and a spare ring set, pm me with details on how you want to do it, thanks.

[deerehunting]

What brand pistons does mfg supply carry? I'm assuming they're priced cheap because they suck? Just curious, Thanks