Engine building ???s

[Metal Leg]

Hey guys, I'm pretty new here. I've been following the 250R section for a few months now. I recently traded my 03 KFX 400 for an 88 250R. Might sound like a dumb trade but I was glad to be rid of that Kawasaki and I've been wanting an R for years.

Anyway, when it comes time for a rebuild, I'd like to go with either a 310 or 330 big bore kit. I realize there is some case machining required for the 330. I guess my main question is, which cylinder/piston/pipe combo do you guys prefer? I was leaning towards the CT 310 power package. It comes with the Pro-X cylinder, piston, Delta V-Force reed cage, Keihin 38mm PWK Airstryker carb with cable, and a CT midrange "National" pipe and silencer.

On the other hand, there's the ESR 310 kit with the TRX7 porting for woods. Get a 38mm Airstryker carb, TRX7r pipe and silencer, and ESR 250R RB2000 reeds.

Which set up would you guys prefer? I primarily ride in the woods, harescramble style and the occasional motocross track. Would a powervalve be a worth the money? Are they dependable with the extra moving parts?

Also, I hear the CR igniton is an awesome upgrade for the R but will the lighter flywheel ruin my lowend torque? I know this is alot of questions but I want to build it right for my riding style when I do it. Thanks guys!

[addictedtomud]

Definitely go with CT before ESR in my opinion. Even the woods port from ESR will feel like a light switch, which is not desirable for harescrambles and woods riding. I have heard alot of people have to get ESR cylinders re-ported b/c they are disappointed in them, so it is worth the extra money to go with CT.

In the same line of thinking, a powervalve further reduces the lightswitch powerband, so I would recommend it as "worth the money." Moving parts are not that big of a wear item.

As for size, go with a 310 or 350. Skip the 330: If you are going to the trouble of boring the cases for a 330, you might as well go 350.

Don't let anybody tell you 350cc is too much power for woods riding. It is really not peak hp you are after, it is torque. With a CT350pv, you can pull a 14T front sprocket and spend most of your time in 3rd gear. You are going very fast due to the gearing, but spending less energy (shifting less). And when you do get into the open field...dam that motor will pull!!

[pdxbigfoot]

Arlan Lehman at LED Performance.
You will have more grunt than you can imagine with or without a powervalve.

[pope59]

i have a ct 350pv that i had Dennis Packard report to a heavy dune port and i have the cr250 ignition as well with the trx 9 pipe gearing 13-41 and let me tell you it pulls hard and is sick fast even with my 39 pkw it hits hard i have a 41.3 lectron from Packard too but i just cant get it to run right with it on the bike

[Metal Leg]

I would love to have the CT350PV kit but the price tag makes me pucker up my sphincter.