Yz250 Eric Gorr big bore kit reviews?

Is there a big difference between the 265 and the 295?

Are they more reliable?

Is it worth the money?

Am I just buying unusable horsepower?

It sounds like more bang for you buck if you needed your cylinder replated.

I race both 250 and 450 classes and my bike does fine as is. But with a big bore kit and a port and polish job I'm guessing it will rip even more?!

Or would I be better off going stock and getting it ported and polished?

The best bang for the buck is the 295 for $660 compared to $600 for a 265. Considerably more power and torque, although still not a 450 power wise. If you need plating you might as well do it. Doesn't cost much more.

Go with the esr 325 or 345 jug hahah all the power you'll ever want :)

That's what I'm thinking about doing, I like the fact that a 295 has almost double the piston life. But does it shorten the life of the cylinder? I just don't want a bike with too much power. I can ride the stock bore like a 125, and have a lot of fun on it. Will the 295 have a lot more power or just a different powerband?

Depending on the porting optioned, the 295 will more power all around. The majority of the gain is going to be in the low and mid range. With the 295 you don't have to rev it as much, so the top end life is going to be greater.

Most rules sanction you can only ride a stock bore in the 250 class...so if you want to run both classes you need to stay stock bore. If you want to run only with the 450s then the 295 kit is the way to go.

I can ride the stock bore like a 125, and have a lot of fun on it. Will the 295 have a lot more power or just a different powerband?

Dude ... both.   I have a friend with a healthy YZ144.  His 144 hauls much better than a stock 125, but compared to my 295 with mo betta porting, his 144 feels like it has at the very most, 70% the peak power, and a power band about 30% as wide.  It's like comparing a 1300cc Toyota Corolla against a nice small block V8.


You can short shift a mo betta 295 and keep the revs down, and it'll wear very slowly. But the problem is it's almost irresistible in the loamy straights to not hold the same gear and let it rev way out and sing its song. You get a LOT of speed range out of the higher gears. In the lower gears I'm hardly ever wide open.

Edited by numroe

Yeah I have heard a lot of good things about the 295. What about the 265? Because that's legal in the 250 class also

I love my 295 with mo power. So much useable low rpm performance, if you wanna open it up its super fast and really controlled power. Just like a huge electric motor.

Go with the esr 325 or 345 jug hahah all the power you'll ever want :)

Has anyone here tested the ESR 325 vs the EG 295 side by side? I am going to go big bore soon also but I'm kinda torn on which to get right now.

Sadly I have not seen any other 250 2t's that can be bored that big :/

Its a new cylinder.

Eric offers the 295 for the Yz250 cr250 rm250 and kx250. Believe it or not they all use the same piston. But i believe the Yz is the only model to go bigger then that with the 325 and 345

I had a 265 before the 295 and the 295 makes more power and torque especially at low Rpm. The 265 feels like a stock 250 powerband just a little stronger. For the extra $60 the 295 is the way to go. Even though I'm having problems with my 295 now, but I think it's a rare issue. Check out my thread if you want to see. He's done some other bikes of mine with great reliability.

Thinking eric has some crazy big bore for the cr 250.

Eric Gorr kits make good power and are extremly durable. I put well over 100hrs on my first top end and I rev the piss out of it.....plenty of compression and the cylinder is still mint. I could have put on several more hours without any issues. I run 25:1 all the time so that could be a factor.

All my other bikes are great but I'm having a problem with my 295 cylinder. The exhaust bridge between the exhaust port and boost valve sliced a gouge in my piston twice. The first time at 20 hours. This time at 5 hours. We're gonna use a different cylinder. You can follow along in my thread if you want to see pics or follow along. He said he is taking care of it this time as well but said it might be the last time. Bike is in perfect mechnical shape as well. Holds 6 psi leak down and cooling system holds 15 psi overnight so it's not lean or over heating. Has to be the cylinder

Ill checkout your thread! The 295 sounds like it's the way to go.And does the 265 last longer also. And is there anything else you will have to do along with the big bore kit too make it run right?

Both the 265 and 295 should have the same reliability. He claims just as good at stock and my other bikes have been just as reliable as stock. Just think there's a problem with this cylinder, that's all

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