I have a couple of question for anyone that has a 250R with a 330 big bore with or without a Power valve. Question 1 is are you happy with it and where did you get it ?? 2. How does it compare to a banshee for power and gas mileage??( I know the mileage is not good on either but which one is worse?)

PS I have been considering a ESR 330 for my 87 R (possibly a powervalved cyl.)

 

I have had 2 ESR Motors and was extremelly happy with both of them.My last was a 310 and now have a 370 PV.You will love working with ESR and their Products are Top Notch. Late,zubbeyboy

 

I have an ESR 330 PV, and I love it.

I haven't really compared it to a Banshee for power or fuel consumption, but I can tell a difference in fuel consumption compared to the 265 motor that I used to have.

 

Yeah, the fuel consumption kind of kills you. They are pigs. I like esr's work too, but they dont build the fastest stuff, they are conservative with their porting, but yet reliable

 

If are leaning towards the 330 because you think you will not have to split your cases i would think again. I am almost positive that '86 and '87 250r's can only do a 310. The '88 and '89 you can run as big as a 330 without splitting your cases. Just a thought.

 

I love my 330, it's got mad power and not having to split you cases is nice. The dude I bought mine from had his ported by TC racing which is a 4-stroke specialist but does work for national riders like he is, I've only seen ESR and TC do that kind of port work, bad ***!