85/86 ATC250R with long rod/spacer plate

[Blown 331]

Anyone running a spacer plate in their 250R? I'm looking at buying/building a motor and I was wondering if I can run the spacer plate or will the spark plug hit the frame?

[KASEY]

You only need a spacer plate if you run a short rod piston on a long rod motor,,, if you run a long rod and the proper piston you don't need a spacer plate,,,, no matter what engine you run it in,,,

[Blown 331]

Seems like a lot of people run a long rod in a 85/86 motor with a spacer plate or a 85/86 style piston in a 87-89 motor. So either way you need a spacer plate. I've heard the long rod with short rod piston/spacer plate gives you more crankcase volume and gives you a better rod ratio which increases the life of the piston. So I am wanting to use a spacer plate but I just need to know if it will fit.

[atc86r]

I have spacer plate and 86 piston. Couldn't use oem spark plug cap because of frame. Its a pain in the arse for an atc. Wish I still had the short rod. They rev better also. If your looking for advice stick with the short rod.

[deathman53]

I have that setup, I have a cr 250 igntion and its not that bad,, its been awhile since I had a stock one, with the stock head its not bad, with a cool head, its bad, but doable. I had to grind part of my frame so that the spark plug was easy to change with my 330 kit, the 86 frame I didn't. I needed a new crank and the price of a oem short rod was ridiculas, the 88/89 crank was $200 or so, big difference from almost $350. If you need a crank, get the long rod and use a long rod piston, the long rod lessens wear on the piston. And also it opens up options to most big bore kits as some require a long rod. I was told the spacer plate makes for a smoother hit, it seamed that way also when changed over.

[atc86r]

At least keep ownership of the short rod. You can have it rebuilt. Mine was used for core charge. At the time I didn't know the costs. If you have it you won't have to shell out the big bucks if you want it in the future.