2nd Gen 200X piston identification help

[Ride_Red_Man]

Hi Guys!! I recently picked up an 86 200x and pulled the top end looking for a knock. I found the knock was a bad cam and followers, but when I pulled the head to inspect the bore I found something that made me scratch my head. (pun intended lol!) The piston appears to be domed pretty good, (its been over 10 years since i've had a 200x head off) and there is no oversize indicated anywhere on the piston. I'm assuming its still at stock bore but what really makes me wonder is the following. The piston has a very promenant "DG' stamped in it, almost looks done by hand. Has anyone ever seen this or know who may have manufactured this piston? And is thos a high compression piston? I am going to pull the jug this weekend and get measurements and better pics of the piston and check the bore specs. but so far I have the following picture of the piston top. Thanks Guys!!

[RIDE-RED 250r]

Was working on this engine with my brother some today and did some measuring.

Found the piston to be 66.50mm....I measured, re-measured, and measured again... 66.50mm.

I also found the raised dome on the piston to measure approximately .075" rise give or take a couple of thousandths due to a little leftover carbon.

I did some looking around and have so far found no manufacturer that offers a 66.50mm piston for an 2nd gen 200x.

At this point after finding a pretty worn/scored rod at the wrist pin end, he will be getting the crank rebuilt and it's looking like it's going to get a new sleeve as well since we can't seem to figure out where this 66.50mm piston came from.

Anybody have any ideas on this mystery piston?? Just curious at this point...

Is there some other piston application for another machine that could have been used here???

[Mickey Dunlap]

Need to see a side and underneath pics.

[RIDE-RED 250r]

OK Mickey, I will be getting together with the family again tomorrow and will get more pics of the piston and post them up..

[Ride_Red_Man]

Here are the pictures you requested Mickey. Please let me know if you need better ones or more information. Thank you.

[Mickey Dunlap]

Here are the pictures you requested Mickey. Please let me know if you need better ones or more information. Thank you.

Looks like some cast car piston with those thick rings. At Powroll we would some times use Honda generator pistons,car piston and other OEM pistons for different kits. DG might have had them made in Japan or did the same as Powroll if they had a machine shop. At this point I would say you are going to have to re-sleeve it and bore a new piston into it. To do all that you are looking at about $300 if you are going back to a high compression piston.

[Ride_Red_Man]

Yeah that's what Joe (ride_red_250r) and I were figuring on having to do when we took the bore measurements. More than likely if I can find a sleeve I may be in contact with you to install the sleeve and get a piston and cam from you aswell Mickey. But it will be in a few months. Gotta get the money and find a sleeve first. I haven't started looking yet but probly will tomorrow at work. Thanks for the info Mickey it is greatly appreciated.

[Mickey Dunlap]

Yeah that's what Joe (ride_red_250r) and I were figuring on having to do when we took the bore measurements. More than likely if I can find a sleeve I may be in contact with you to install the sleeve and get a piston and cam from you aswell Mickey. But it will be in a few months. Gotta get the money and find a sleeve first. I haven't started looking yet but probly will tomorrow at work. Thanks for the info Mickey it is greatly appreciated.

The price I gave was for labor and the piston and sleeve total.

[Ride_Red_Man]

Thanks Mickey, I will be rounding the money up as soon as I can. Like I said I will be needing a camshaft, crank rebuild, and I'd like to put new valves in it. If you'd like to PM me with info and prices instead of posting on here I'd understand. I found the wrist pin journal is maled up pretty bad, so that why im saying a crank rebuild. Thanks Mickey.

[Mickey Dunlap]

Thanks Mickey, I will be rounding the money up as soon as I can. Like I said I will be needing a camshaft, crank rebuild, and I'd like to put new valves in it. If you'd like to PM me with info and prices instead of posting on here I'd understand. I found the wrist pin journal is maled up pretty bad, so that why im saying a crank rebuild. Thanks Mickey.

If you need help just give me a call.

[Ride_Red_Man]

Thanks Mickey, I'll be in touch.