there are some stock cylinders beating the 310 kits. i was gonna do big bore but did stock cylinder instead mainly cuz of money issues lol all depends what ya want i guess stock sleeper or big bore inialator (never said i could spell lol

 

Yes the kit is a really good price! In my experience if you have a well running stock cylinder and spend the money on some good portwork and get it set up and done right, it should be pretty close to the box stock esr 310 kit with their "porting" etc. Now if you get the esr cylinder kit, and spend a bit extra to have someone do some porting to that and set it up for race gas, youll be pretty surprised with it. And then of course after that youll be looking for something bigger, and bigger, the vicious cycle haha.

 

I got the ESR 310PV and woww what a difference over stock setup, so much faster and more torquey. But I also went with new everything, ESR reeds, 38mm tmx, elim kit, trx5 pipe over stock cylinder/carb with a fmf fatty pipe. I love it, I'd say go with the 310 and have Neil or carlos port it n run race gas and you should be able to clean up 450s + banshees that aren't over modified.

 

Esr kit's are real nice setups when there setup right you should be ok with your carb it should feed it you may need jetting you already have the esr reed block to mate to the cylinder, you figure a new 310 sleave is around 140$ to 160$ then have it pressed in what another 75$ to 100$ port work another 100$ + then your piston another 150$ atleast with the 310 you won't have to open up the cases for the sleave to fit its plug n play the only thing diferent is the looks. a good freind of mine has the esr 310 on a 86 atc with a rad valve and a keihen a/s full fmf exaust and its a good running machine i think the esr cyl its somthing with its porting that make them run crisper and seem to start really well it's kinda a neck n neck race between the 2 but if the money is there i'd go with the esr.

 

I went with the stock cylinder and you will be amazed what can be done with one when built by the right person with the right parts. I can't wait to run some 310's and 330's at the next dune trip. Wish I had some haulers to try instead of sand skate 2's although I do really like the skates. I hear they cost you some hp compared to some haulers which are lighter and hook better out of the hole.

 

I went with the ESR 310 kit from Carlos, had it ported for xc and set up for C12 race gas. My original setup was a stock cylinder (66.75 bore) with UNI, no airbox lid, TM38 carb, V-force reeds and Paul Turner type-6 pipe with fatboy 2 silencer. I kept the same setup but added the 310 kit (and rejetted of course) and all I can say is WOW! I went from a 13 tooth to a 14 tooth sprocket and it pulls A LOT harder than my stock cylinder did with the 13 tooth. I had some initial concerns about the ESR seizure issues, but I took my time on break in and have had no problems with it at all. I know you can get a stock cylinder to run like mad, but I subscribe to the statement "there's no substitute for cubic inches". I believe that like for like mods on a stock cylinder vs a 310 will still favor the bigger motor. My .02.

 

You are right about there being no replacement for displacement, but if your combo isn't matched up right and/or your jetting is off, then all that extra displacement isn't gonna help very much. Also nothing beats oem quality for parts. While both Neil and Carlos take the time to listen to you and go the extra mile to get the job done, I wouldn't let CT, Duncan, Trinity and whoever else I left out port my cylinder. While they may call it a National kit or whatever I know that you aren't gonna get the same exact portwork as their pro's did. I don't think my cylinder would have been the same if the guy hadn't retired from pro racing and it still isn't quite to the specs he usually does due to the fact that it had been ported before, but I am still quite happy it and yes it too will pull higher gears faster than it did with the lower gears and just the first portjob done. I think the bottom line is that you need to have all your engine portwork and parts to compliment each other to really get the most out of your engine along with it be jetted correctly no matter what size your engine is. Also the pricing on the new ESR kits is very good, which makes them even more tempting to try one. Maybe someday, but I'm happy with what I got now and when that isn't enough or I wanna go even faster then I just break out my cr500 and ride it anyways lol.

 

Completely agree bud. No disrespect intended. I don't think there's really a right way or a wrong way to go about building more power. I kept going back and forth on building my stock cylinder or getting the 310 kit. My decision was actually made for me when I had to replace the cylinder on my other R. I figured, why not swap my stock cylinder onto that one and get the 310 for mine. I actually came out cheaper overall. I'm happy with mine and I'm glad you're happy with yours. As long as everyone is continuing to build their R's and having fun with em, I'm totally good..lol Oh, and I have no doubt your Cr500 gives you your speed fix...lol

 

Hard to beat $599.99 for a new 310 ESR cylinder kit. I would not get the $499.99 with ESR "as cast porting", they are very rough and all over the place. And as everyone knows; good porting/flow bring these cylinders to a much higher performance level.

Carlos.

 

Look at it like this, the ESR 310 kit is, $499.00 + the spacer plate kit if to have the long rod crank. Then a Pro-x $899.00.
Now the ol Pro-x, is a tried & true cylinder kit & the ESR, yes there have been some problems, but I cant deff say if it is the cylinder causing the problems or something else.
If those problems had been every cylinder, all from a single production run, then you could pretty much point a finger. Nobody would know that though except ESR. Theres a bit of difference in the quality of the cylinder kits, so care should be taken when building the ESR kit as compared to the Pro-x.
About the same thing as tools if you think about it.
You can take a cheap Globemaster drill bit & do the same job as a high priced high qualiy bit from McMaster Carr tools, just a mater of how it is used. Slow the drill speed down on the Globemaster & it will drill just as good & last just about as long as the high priced high quality drill bit.

One other important thing, which I guess could be the most, who is it still making stuff for the ol 250R, when just about all the other shops, including Honda, have kicked it in the ditch & jumped on the high priced money making 4 poke band wagon.

We might be having some problems, but Eddie aint kicked us in the ditch.
Neil

 

Hard to believe that we are one of ESR's best customers; we purchase cylinder kits weekly, have come to know the good and the bad intimately .

Plus; Wiseco has increased the taper on piston kits for the 310, minimizing seizures like we had been seeing 6-12 months ago on ESR 310 kits. Now the PV is still an issue and we see a lot of failures inherent in the ESR PVdesign; sometimes causing severe damage to the rest of the engine.

Overall; ESR has made some improvements, and I agree 100% we need to support those that support our beloved 250R's...and the excellent low pricing doesn't hurt

Carlos.

 

You are right about supporting those that still support us 100%. However price was a big deal at the time(so was time as I had 2 weeks before goldrush) as was supporting people that we know personally and still support 250r's also. Also not having to deal with shipping was nice too. I was able to get stuff at such a discount that is was to good to pass up. I have no doubt that I will do business with the site sponsors eventually, but shopping locally also helps keep our own local economy alive also. Like a lot of things in life, there is some sort of trade off involved. I would like to say thank you to EVERYONE that still loves and supports 250r's. I know that both of you, Neil and Carlos, spend a considerable amount of your time helping all of us out with advice and such whether or not we are/aren't customers. That says a lot right there about the kind of people you both are and we are all lucky to have you both here for us all.

 

Lets hope my 330 ESR is all to snuff I wanna ride. My first 330 leaked coolant and the PV chaffed the piston bad in a 1/2 hr of use.

 

ESR 310 non pv cylinders are by far the est bang for your buck. The TRX9 port work I had was not shabby. It does have tons more potential though. I just pulled my cylinder off and shipped it to Neil for his ultra mid range port work. I am looking forward to blowing the pants off some big four pokes at buttercup. My 310 with mods listed in my sig did much better than my ported stock cylinder. Other than shear power the biggest noticable difference was the torque gain and the ability to lug the bike a little.

 

IMO any new cylinder kit for $500 is a great deal; just note the limitations and work around them...

Carlos.