esr310 powervalve or not?

**threewheelin-feelin** · 10-01-2012, 06:44 PM

ok guys my 250r is getting very tired and its time for a rebuild. im going to be purchasing a new left side case from a member here and im trying to deside what i want to do with this bike. ive been looking at the esr 310 kit and i see they have a powervalve cylinder and a non powervalve cylinder. i pretty much only use this bike for drag racing and use my 350x or bigred for everything else. so what would you guys recommend on this? money is a problem and i will be selling my 200x to do this. im probably going with the 38mm airstriker from esr as well. and i have a fmf fatty already so give me some recommendations guys. thanks!!

also if yall have recommendations for another way to build it on a limited budget let me know

**KASEY** · 10-01-2012, 07:36 PM

no powervalve needed

**RIDE-RED 250r** · 10-01-2012, 08:12 PM

^^^I agree^^^

Especially on a budget. Have ESR or another reputable shop port it for mid-top and it should run well for what you like to do. I'm told by several who have experience, that the "as-cast" porting is not very good. And on that advice I had my ESR 350 ported TRX9 (mid-top) by ESR for the extra $100. It runs very strong and I am very happy with it. I would spend the extra $100 on the custom porting rather than the PV setup myself...

**JasonB** · 10-02-2012, 01:59 PM

agreed on the no powervalve; i am extremely satisfied with my 310 non PV motor and it runs strong. I just switched to race gas on mine too, and i only did the trx7 port work too so im more for mid and playing all around.

**NOS_350X** · 10-02-2012, 04:59 PM

Originally Posted by JasonB

agreed on the no powervalve; i am extremely satisfied with my 310 non PV motor and it runs strong. I just switched to race gas on mine too, and i only did the trx7 port work too so im more for mid and playing all around.

With a good, carb, reeds and a bad ass pipe.
310's can run good, but do all the work around the cyl too

**threewheelin-feelin** · 10-03-2012, 12:07 AM

ok what do you guys recommend for reeds? and how bad is it to run a fmf fatty?

**KASEY** · 10-03-2012, 12:17 AM

i run only boysen dual stage reeds in every 250r i own

**NOS_350X** · 10-03-2012, 12:52 AM

Reeds, A rad valve is a good choice for midrange, Vf2's and ESR for topend. An FMF pipe isnt bad there are just better options out there.

**riverrat** · 10-03-2012, 06:30 AM

I just built a ESR power valve motor and all I can say is WOW. Takes off like a 4 stroke and revs out like a two stroke. Very smooth ride-able power band. Loose the fmf pipe. Get a Paul Turner high rev or ESR atc5. Night and day on the pipe change. Set it up to run the highest compression you can for the fuel you intend to use. Also I am happy with my ESR reeds. ESR is pretty cool, if you purchase a bunch of things together, they will cut you a nice deal usually. They were giving me the billet goodys for half price when I got my cylinder kit.

**RIDE-RED 250r** · 10-03-2012, 08:32 PM

Originally Posted by riverrat

I just built a ESR power valve motor and all I can say is WOW. Takes off like a 4 stroke and revs out like a two stroke. Very smooth ride-able power band. Loose the fmf pipe. Get a Paul Turner high rev or ESR atc5. Night and day on the pipe change. Set it up to run the highest compression you can for the fuel you intend to use. Also I am happy with my ESR reeds. ESR is pretty cool, if you purchase a bunch of things together, they will cut you a nice deal usually. They were giving me the billet goodys for half price when I got my cylinder kit.

I can confirm to that.. I bought my big bore kit, ATC5 full exhaust, reedblock all at the same time. They didn't charge me for case boring and ended up charging me almost $200 less for all the stuff I bought than if I were to order online. Make sure you call to place your order, that's what I did. Plus I have heard quite a few people have had alot of trouble with their online ordering service...

Your FMF system will get the job done pretty good, but to get the full potential out of your 310, do as other suggest, get the ESR ATC5 or PT pipe. I have not run a PT, but my ATC5 pipe works awesome with my big bore.

**pantera1975** · 10-03-2012, 08:48 PM

I have a 330 with out the power valve. You can lug the motor in a higher gear than stock. I have esr's clean up porting called trx9. I'm told having a pro porting job will really make a differnce. You will have to smash you fmf pipe on the back side for coolant hose clearance. I run a esr exhaust,39mm carb v force reeds and a full airbox without the lid. Lots of power. Gotta be careful riding it. IMO no need for the power valvePeople say they have bad bottom end, Yes compared to a pro ported 330 but alot more than stock.

**pcs** · 10-03-2012, 10:01 PM

if you go with the esr kit, IMO if you are going for high hp #s i wouldnt spend the extra money on their port job and just get a drag port from a shop that builds drag engines. like pantera said, getting them ported really works.for reeds, i wouldnt even consider anything from boyesen, they dont compare to vf 3 or the esr billet reeds for building high hp. if you go with esr reeds get the ones without the built in spacer bc it will give you more clearance with the rear shock and carb. carb 39mm or bigger with a UPP manifold. you can also play with the esr reeds since they are aluminum so you can have them opened up a bit too. fmf pipes just look shiny and arent good drag race pipes.

**NOS_350X** · 10-03-2012, 10:27 PM

Originally Posted by pcs

fmf pipes just look shiny and arent good drag race pipes.

Well then my pipe is the only option, Or OOF

**MTS** · 10-03-2012, 11:19 PM

Anyone care to explain why they do not run a Variable exhaust valve other than the extra 100$??? figure "THEY" have been running them in every two stroke for the last 20 yrs for a reason...Less time and more comp down low and More time and less on top? whats to loose? Just a question

**pcs** · 10-04-2012, 01:05 AM

NOS350x: if fmf is your only option then go for it. from my personal experience with dyno testing fmf pipes on quadzillas make less hp than the oem, on lt250r they only shift the power curve and rev out further, and on a trx250r i saw dyno testing pipes, it was the 2nd worst pipe ahead of a dg pipe and way behind esr, ldr, pt, and shearer.

MTS: pv or variable exh motors work better than the non version by spreading the power band over a greater rpm range. when the manufacturers design engines, they are usually designed to operate over a wide range of applications, hence a pv engine with work better. however for strictly drag race/ high rpm operations the pv will not be used bc it will be opened the entire time so it is not needed and will just add more moving parts to the engine and require you to run pv pre mix oil to keep you from gumming up the pv unless you like to take off your top end just to clean it. adding a pv to the engine will not add hp only spread what you already have.

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esr310 powervalve or not?