NEW ESR 310 evaluation

[wes350x]

OMG, I finally got my new motor tuned great, (had to get a friends carb, mines wore out) It was amazing. When it would hit the powerband it suprised the hell out of me. Even though I had a lil trouble with the port work and had it redone by Eddie himself, It was totally worth it. I cant explain how impressed I am. Now I have to order another cab tomorrow but that would be worth it also.

[trx250rider]

thats awesome..im glad you got everything worked out on it..ill have mine on this week so im excited to try it out..what setup did you have before and how does it compare?did you get a temp gage also?

[Honda 250r 001]

thats great. i think im going to break down and buy me one here when i get my dirtbike sold. hopefully i dont have to get it reported though.

[1promodfan]

I've got mine bolted up and I've done 4 heat cycles. The only problem is I can't ride until I get my a-arms back from the
powder-coater. I got the TRX-9 pipe and an ESR silencer too, let me tell ya, it sounds awesome. Wes, its good to hear that it runs that good. I can't wait to try mine out!!!

[wes350x]

Originally posted by trx250rider
thats awesome..im glad you got everything worked out on it..ill have mine on this week so im excited to try it out..what setup did you have before and how does it compare?did you get a temp gage also?

I had a 265 yz piston set up before, but I never could get it to run at peak performance cause of the bad carb. It has been a thorn in my side. The 265 performed good, but the 310 is awsome. I also did get a temp gauge and when I was putting around right before I was loading it up I checked the temp and it was close to 200!, But I was playing around in the yard, when I ran it hard then checked it it was a bit over 150. I also ran 4 heat cycle through it the said f*ck it and hammered on it. Now Im through my first tank of gas so I believe im good to let it rip.

[Honda 250r 001]

wat carb are you going to go with? readin this i cant wait to get my kit. So cheap for so much power.

[wes350x]

Originally posted by Honda 250r 001
wat carb are you going to go with? readin this i cant wait to get my kit. So cheap for so much power.

I have the 38 a/s now, may go to the 39mm Pwk, gonna talk to Tom at ESR in the morning and tell him my info and see what he suggest.

[albertp86]

Is your 38 not working good? Because I think Tom is going to tell you to go with the mikuni 38 or the keihin 38.

I am ordering my 310 pv next week as soon as I get back from my trip to the dunes. I'm going with the 310 pv, 38 a/s, 3 mm stroke, 9 pipe centermount.

Just curious, do you have an extended swing arm, are you able to keep the front end on the ground?

[wes350x]

Originally posted by albertp86
Is your 38 not working good? Because I think Tom is going to tell you to go with the mikuni 38 or the keihin 38.

I am ordering my 310 pv next week as soon as I get back from my trip to the dunes. I'm going with the 310 pv, 38 a/s, 3 mm stroke, 9 pipe centermount.

Just curious, do you have an extended swing arm, are you able to keep the front end on the ground?

Ive tried everything with the carb to get it straight, put my friends on and BAM...everything is perfect. Has to be the carb. I may go back with the 38 a/s but I wanna see what they say about the 39mm. Sometimes carbs wear out I guess like everything else. I have the trx9 (mid-top) porting and dont want the mikuni cause it is a woods carb I think.

[Honda 250r 001]

is the slide loose in the carb? if its fairly tight then im pretty sure everything else is replaceable.

[wes350x]

Originally posted by albertp86
Is your 38 not working good? Because I think Tom is going to tell you to go with the mikuni 38 or the keihin 38.

I am ordering my 310 pv next week as soon as I get back from my trip to the dunes. I'm going with the 310 pv, 38 a/s, 3 mm stroke, 9 pipe centermount.

Just curious, do you have an extended swing arm, are you able to keep the front end on the ground?

I called ESR today and you were right, Tom said the mikuni was a good carb but ended up with the 38 a/s again cause he said of the responseness of the carb and performance. So it was shipped to me today.

[FL-R]

I finally got mine runnin cool and tuned in about a week ago, Power hits hard in the midrange, I dont have to shift as much in the turns and in the tight woods. So far im really happy with my ESR setup.
I bought the 310 kit, pump gas dome, 38 a/s, trx 5, air box eliminator, and did the longer rod (mines a 86). I have less that 1400$ in my motor and it really rips now.

[wilkin250r]

Unless it was the slide, I want to know how the carb was worn out?!?

[wes350x]

Originally posted by wilkin250r
Unless it was the slide, I want to know how the carb was worn out?!?

I wanna know too. Ive tried just about everything, I dont think its my slide cause im using it in the carb now. I think its the seat that the needle goes it, woddled out cause it was running way too rich, tail pipe would stay wet and nasty. Oh well my troubles are gone cause Ill have a new one soon. It maybe sold to EXtreme-, for a good price, as a parts carb, waiting for payment.

[86 Quad R]

glad that engine worked out good for you..... i must admit that when i first saw the cylinder. i had my doubts.

overall i think you'll be much happier with the 38as. the 39pwk is a good carb but imo is best suited for dunes and/or dirt drag. speaking of carbs. have you by chance paid attention to what the number is on the slide? also i wouldnt be too qwik to sell the old carb yet. if memory serves me right. the orfic(if it turns out that whats wrong with it) can be replaced. :cool:

[wes350x]

Originally posted by 86 Quad R
glad that engine worked out good for you..... i must admit that when i first saw the cylinder. i had my doubts.

overall i think you'll be much happier with the 38as. the 39pwk is a good carb but imo is best suited for dunes and/or dirt drag. speaking of carbs. have you by chance paid attention to what the number is on the slide? also i wouldnt be too qwik to sell the old carb yet. if memory serves me right. the orfic(if it turns out that whats wrong with it) can be replaced. :cool:


I think the slide is a 7...I believe.

[86 Quad R]

a #6 i believe is best suited for the R

[albertp86]

Any more updates on how everything is going with your new motor. I hope all is well. Mine should be here soon.

[wes350x]

Motor is running great. Sputter issue was from a bad carb and a new one fixed it all. I just purchased a CR ignition and Im waiting for it to come so that will be my next project for it.

[86 Quad R]

what compression are you running on this 310?

[Honda 250r 001]

wat slide should be in a pwk 39 carb for a trx 250r. i had no clue there was a difference or that you could get different ones.

[86 Quad R]

A #6 :cool:

[wes350x]

Originally posted by 86 Quad R
what compression are you running on this 310?

I can say I honestly dont know. I recently finished the breakin and hopefully do compression checks soon. It has the race fuel head but Ill post whenever I get around to do it.

[250rdrag]

i am the guy that thought the head wasnt sealing right. i got it back from esr and still wasnt happy at first. jetting specs seemed to be much leaner than what i was used to. i finally got 38 pwm tuned for it and i am quite pleased now. it is as strong or stronger than my drag ported pro-x 310. it runs real good now.

[redrider419]

Whats your jettings at on your 38 a/s Wes, I just got the same setup as you with 110 32:1 fuel. SPuttering/bogging at about 1/2-3/4 throttle, im at 180 main, 50 pilot (i think), and 4th on the needle clip (very bottom clip)

[wes350x]

I think its a 178/48 or 50. Clip in the middle. I havent had to jet it since then. It still runs great.

[1promodfan]

On mine right now I've got a 175 main, clip in the middle and (I think) a 45 pilot. I might be able to go down one more size on my main. Mine will sputter every now and then, but overall it run great.

I went riding about 3 weekends ago and I had a great time just hitting the trails. I did a little drag racing and I was VERY impressed with how it performed. I outrun a few 450's (both Yamaha's & Honda's) and a couple Craptor 660's. I raced 2 different Craptor 700's and they both got me by about 2 quad lenths.

Now I'm a big guy (6'1 268lbs) and most guys I was racing weighed somewhere in the 165lb range. So I thought I did good considering the power/weight ratio.

One guy had a GYTR edition YFZ 450, and he would get the hole shot everytime, but time I pulled 5th gear I was passing him. He later told me he was impressed on how my 250R ran. Now I'm not saying that I cleaned house or anything because there is a lot of fast thumpers out there.

[ckelly30]

the 310 is a beast. I finally dialed it in today. i have the trx 7 set up and i think 175 or 172 main with 52 pilot and 38 a/s. my compression is at 180.



will the compression change over time?

[Ruf Racing]

Originally posted by ckelly30
the 310 is a beast. I finally dialed it in today. i have the trx 7 set up and i think 175 or 172 main with 52 pilot and 38 a/s. my compression is at 180.

will the compression change over time?

Sure over time, the compression will decrease slightly. This is a non-power valve setup?

[ckelly30]

Yes it is a non power valve set up.

will the compresssion loss rate be different between a pv and npv cylinder?