CR piston on the EC250

[mou636]

Hello all. I have an EC250 06 that I am replacing its piston. I read that a 86-96 CR250 piston is a direct replacement. So do I just put that on and I am good to go? Would it change some engine or performance characteristics? Also I read that the skirt on the CR piston is a bit different than the Gas Gas and that results in better low end.Is that true? Has anyone made the swap? I am asking because I found a Prox CR piston on ebay that is a lot cheaper than a Vertex for the Gas Gas and I believe that both brands are very high quality so I wouldnt mind saving a few euros to go to some other upgrade.

[Fesart]

Originally Posted by mou636

Hello all. I have an EC250 06 that I am replacing its piston. I read that a 86-96 CR250 piston is a direct replacement. So do I just put that on and I am good to go? Would it change some engine or performance characteristics? Also I read that the skirt on the CR piston is a bit different than the Gas Gas and that results in better low end.Is that true? Has anyone made the swap? I am asking because I found a Prox CR piston on ebay that is a lot cheaper than a Vertex for the Gas Gas and I believe that both brands are very high quality so I wouldnt mind saving a few euros to go to some other upgrade.

If you have a look at the crossover list you can see that the GG piston is compatibile with thr Tm 250 piston. Because in some other forums is stated that the Cr 250 piston fit the Tm 250, for the transitive property it should fit the GG as well! But it should be better to have both in hand and take some measures.

[webmaster]

I have never heard this before...

If these pistons are the same - then the part numbers should be the same for an aftermarket vendor... Be careful - it might "fit" - but it might not be "right"... e.g. squish and compression might be completely "wrong". (insert picture of square peg being pounded into a round hole here...)

jeff

[noobi]

The rod is a direct cross over, and I remember there being a rumour about the piston, but wasn't sure if anyone ever confirmed it. Also, I don't think the years that you listed were the ones suggested as the piston crossover years.

Also, I wouldn't go as far as to say ProX and Vertex are on the same level of quality, but ProX isn't bad.

[Zman]

I wrote this up about a year ago.

http://www.gasgasrider.org/forum/sho...n+cr250+piston

[webmaster]

Jim Cook probably knows more on this issue. I vaguely remember that you could - if you were replating the cylinder - have it bored and plated to accept a CR piston.

It may be that Z-Man's bike was bored to make it accept the CR piston in his case..

Anyway, just warning that you should double check the CR piston crossover rumor....

Jeff

[SS109]

Well, I can add that my '02-'04 EC250 is currently running a Vertex 23249B 66.34mm piston which says it also fits '89-'94 Honda CR250. It was the same size as the one I removed. Seems to work just fine.

[Leo]

On my 2005 I have used CR pistons.....no problems, any noticeable difference

[Zman]

The XC250 cylinder I had was an original GG cylinder that was well worn and it had a cheap Namura Honda 250 piston in it when i got it. I had it diamond honed to clean up the bore so I needed the larger piston.