Piston deck heights 200X, help..... PLZ : I

[Dirtcrasher]

Guys, I'm trying to figure out what the difference is in 1st and 2nd gen ATC200X pistons.

I have a stock 86/87 and measured that from center of pin to bottom skirt and upper deck (the flat part). And I know what stroke both models have from the service manuals.

Could anyone with a 83 - 85 200X piston measure the center of pin to deck and center to the bottom skirt.

If you can't do the center of the pin, just do top of pin to top or bottom of pin to bottom. Then all I have to do is add 1/2 the diameter of a wrist pin.

Pictures would be even better and this can be done with any old 200X piston laying around.

If I can't get this measurement, I'll get a used crapper in classifieds.

Thank you for any help.......

[RubberSalt]

According to the 9th(<-read first), 2nd, 4th, and 6th post, same part number from some manufactures. http://www.3wheelerworld.com/showthr...iston-vs-86-87

[Dirtcrasher]

Thanks Salt. I'll still have to look into this.....

[oscarmayer]

dirt, are you wanting to do the 2nd gen? if so, the piston comes out of the hole more with the wiseco piston and you need the wiseco head gasket as it is slightly thicker to compensate.

[Shep1970]

Hey, wait - ive got pics its a wiseco 10.25:1 86/87 200x at tdc pic,
it wont help you d.c. but may help others, the pistons a touch below deck.
Oem gaskets,torqed down, has been run for two years now.
It has never hit head since day one.

Not looking for trouble im just putting it out there.
No wiseco gasket used,just oem

[YTZ drew]

I might still have a used first gen 200x piston of unknown brand laying around. I'll check tomorrow and post a measurement.

[TwiZ]

Hope this helps....

[Dirtcrasher]

Hope this helps....

Thank you bud, but that measurement needs to be in the thousandths range.

I think Oscar is aware that they are VERY close, possibly thousandths. That's what I'm looking for....

Some manufacturers say "1983 to 1987" so it seems anything will work in there but what is the loss. Lower and less compression or raised and higher compression.....

[Dirtcrasher]

dirt, are you wanting to do the 2nd gen? if so, the piston comes out of the hole more with the wiseco piston and you need the wiseco head gasket as it is slightly thicker to compensate.

Well, this is a Big Als and IDK if it's the same as Wiseco, but it gives me more to look into, thank you....

[oscarmayer]

Yep only a few thou difference to by honest. the HG will compensate for your needs. now I know from experiences if you want to check deck height if an installed piston, you need to install and torque the head then loosen and torque like 3-4 times. finally when done, you need to be very careful when removing the head as to not to disturb the cylinder so it stays put and not lift.
if you find it is a few thou below the stock deck on the cylinder and want to bump compression, measure the difference and have the bottom of the cylinder decked that much so the piston is level or even a couple thou over. then a nice decent thick HG will bring you to where you want. the wiseco 10.25:1 done can be closer to 11:1 when done on the 86/87.

good luck and enjoy it sir!!!

[YTZ drew]

My aftermarket piston of unknown manufacture measures at 0.6885 + .2965 (half of the pin hole ID) for a comp height of 0.985". In mm, my caliper read 17.6mm + 7.5mm for the pin hole for a comp height of 25.1mm. There us a slight discrepancy between those two results if you convert the .985 to mm or vice versa, probably due to my cheap digital caliper. If you need it more accurate than that I can go to the garage and get out my nice Starrett caliper, but since it's a no name piston, it will be slightly different than any other brands anyway. Hope that helps, and sorry I didn't get that number for you last time. For some reason I only measured the jug the last time you asked.

[Dirtcrasher]

Thanks guys, I have something to chew on now....