250R into a ESR350 Stroked???

[ghawkman]

I want to upgrade my stock 250R to either a ESR330 stroked or a ESR350 stroked. They said the 350 stroked will put out 72 HP.

They said to use their pipe and upgrade to a 39mm Carb.

Does anyone know about this motor? Is it reliable? Is it as powerful as they claim?

Is there a better setup than what I mentioned???

I like to race up hills and I do A LOT OF DUNIN... FYI


I appreciate any advise and input you may have. Especially if you are speaking from experience....


Thank!!

[ESR350r]

I have an 86 trx 250r with the ESR 330 bigbore with a 5mm stroker crank. With the 330 kit and the crank it puts me at 350cc. I also got an ESR 39mm keihin carb, an ESR reed setup, ESR's K&N airfilter kit so i can run no airbox. I also got ESR's temp gauge for a way to check on it when i race. I also have a hinson clutch basket to handle the power. I currently have an FMF pipe and silencer but I am going to get the ESR TRX11 pipe over the winter. The ESR pipe lets the motor breath a ton better and it allows the motor to run cooler. I hillclimb and drag race for the most part, but i ran in the IRONMAN GNCC race last month and i am running in another GNCC type race this weekend. I have been successful doing both. The motor is definetly mean, i still do not know the full capabilities of mine because i have not fully tuned my carb. I had clutch problems and now that i got the hinson clutch basket i just need to tune my carb but i have not had the time to do it between college and racing on the weekend. Let me know if you have any questions i have a guy who is helping me tune mine in and i know how nice it is to have someone help. I currently have $2500 in my motor and i would still like to get the ESR TRX 11 pipe along with an aftermarket ignition as far as engine mods go.

[ghawkman]

Wow. You have exactly what I am wanting. What gear ratio are you running?? What do you know about the 350 STROKED? Is it worth the few hundred dollars more? Versus the 330 Stroked? Also I hear there is a 370 ESR as well... I also heard that the 330 will rev faster then the 350. Is this true?

Do you have to run pure race gas with the 330 stroked or 50/50?


Thanks a bunch!!!

This is a great help....

[ghawkman]

Do you know your HP? ESR said the 330 or the 350, I can't remember one of them puts 72HP to the rear wheels... Is this accurate?

[ESR350r]

I have not had it put on a dyno, but i have heard of 350cc kits that put out around 60-65 hp, a 350 bore stroked would be close to a 370cc so i would guess that that is your 72 hp.

[ESR350r]

The gear ratio depends on what i am doing and what the contitions are, i will use an 13, 14, or 15 tooth front sprocket and a 38 tooth rear. That gives me a pretty good range for all conditions and applications. When i first started looking in wanted a powervalve motor so i did not do much research on the other 2 motors. ESR has 330, 350, and 380 nonpowervalve motors and the 380kit requires the 5mm stroker crank. they have a 310, 330, 350, and 370 powervalve motor too. From what i understand the 350cc and up are more just for draging, hillclimb, and some dune riding. They also require much more maintenance and you do not have the bores that a 330 has. You also have to have your cases bored for 330 kits and upI like to play ride and GNCC race too much to shell out the extra money and not be able to ride as much. It all depends on what you want to do. It is true that the bigger bores are not supposed to be reved as high even though they are best at high RPMS which is why they require more maintenace. Also the smaller the bore the quicker it will rev out because there is not as much weight getting thrown around. I run Klotz 113 race gas and klotz oil at 32:1 or a little richer. If you really want to know all the details call out to Eddie Sanders (1-559-625-3157) and they can tell you everything you will need to know. I really like my 330 stroked. I have seen CT powervalve motors beat banshees and tear up the hillclimbs and i am at more cubic centimeters then him so i just have to get it tuned in and let it rip. Let me know some more questions you have.