esr 310

[Eddiesanders250]

i am interested in buying the 310 kit from esr. I do only sand riding and i just wanted to know how some people liked their kits from esr. I have a fmf pipe (that i would rather trade for somethin els) i have v-force reeds, and a 38mm carb. I think that this is a good setup. would these work well with the 310kit. I really would appriciate any comments about the 310kit.

[Dave83]

Just got the 310 on my R running again.It is great.You would probaly want the trx9 porting or maybe the 11.I would def get another pipe.ESR has good customer service and are always willing to help.

[Eddiesanders250]

what was wrong with your 310 kit? I thought it was reliable? how long have you had it?

[Dave83]

Nothing with the kit.The rod bearing on the crank went on the 3rd lap the 1st time I raced it.The cylinder had no damage.The bottom end was supposedly low hr,but it had been sitting for a long time after I got it.Anyway,the kit was not faulty,but you need to make sure your crank and tranny are in good shape before bolting any big bore on.

[mxracer97]

I have had an ESR 310 kit with the TRX7 porting, 38mm Mikuni TMX carb, and TRX5 pipe on my quad for about a year now. MX racing is about the only riding I do and so far this kit has been very reliable. I have had zero problems with it, and the power is more than enough for me. Also, their customer service was great. Just my $.02.

[wilkin250r]

The best advice I can offer you is: Do not be cheap.

I don't know what your history is, or what you already have done. But I see SO many people that try to save money and buy a cheap kit, or a do-it-yourself project, and end up paying for it later.

If you don't know what you're doing, a serious performance upgrade is not the time to learn. I see it all the time. On average, a professionally-built motor will average 5-10hp more than a do-it-yourself, with the exact same size and porting. Not only that, the pro-built motor lasts twice as long.

Don't be cheap. Don't do the "econo" porting, go for the real porting. Get the pipe to match, don't just use your existing pipe. And if you haven't rebuilt your engine several times yourself, don't do it now. Just pay the extra money to have a professional look it over, because they will know what to look for.

[Eddiesanders250]

ya i can understand that. that does cost a lot more to have them put it together dosnt it? Also i will buy another pipe eventually but i dont have the money right now. About how much do you think it would be to have esr put together a 310 for me (with parts)

[wilkin250r]

If you're mainly riding sand, you don't really need the powervalve, but you DO want the fully ported version, not just the econo porting.

The kit alone will run about $1000. You should also expect at least another $1000 for them to install it for you.

Now, that extra $1000 for installation isn't just slapping the cylinder on there. It will be for ESR to tear down the bottom end, go through it backwards and fowards, replace anything that needs it, and basically get your bottom end ready to handle nearly double your horsepower.

Your bottom end might "work just fine now", but that doesn't mean it's really up to snuff. A 310 kit will find the weaknesses in your bottom end real quick. That extra $1000 (or more) for installation isn't necessarily buying more power, it's buying longevity and reliability.

[Eddiesanders250]

what do you think the max would be after esr went through the whole thing. with parts. What should i expect to be wrong with it.
here is a picture just so you can see.
P.S. would you recomend a different company, or would you recomend esr?

[wilkin250r]

$1500 is probably the absolute minimum. $1000 for the kit, and $500 for labor and basic stuff that you ALWAYS replace when you do a rebuild. Things like gaskets, bearings, oil seals, ect, but not needing to replace anything big, like a crankshaft.

It might get as expensive at $3500, but I doubt it. $1000 for the kit, and $2500 for the rebuild if your motor is in REALLY bad shape. This is if ESR needs to replace the crank, case halves, shift forks, a couple of gears, clutch, ect.

Much of it would be determined by your engine, if it's in good shape or not. The areas to look for are the crank, counterbalance, and cases. Believe it or not, the cases are fairly common. Just because they look fine on the outside doesn't mean they are good. If ESR finds any stress cracks or wear around the bearings, they'll want to replace the cases, otherwise those tiny stress cracks turn into HUGE stress cracks when you add 20 horsepower.

[wilkin250r]

As for recomendations, it's tough to say. I've never used their kits, I've always done my own work. The only outside shop I have ever used is the local dealership (for simple stuff like boring and valve lapping), and Duncan Racing.

I've heard some good things and bad things about ESR. Then again, I've heard good things and bad things about almost ANY racing company. I really can't suggest any one over the other.

[Hoppedrap]

Love my ESR motor Paid roulghy $3000.00 Look on Ebay there is a guy selling motors it seems weekly for about 1500-2000.00 w/ 310-330 kits.

[djgrooven]

I paid about over $1900 for my motor. this guy from my work use to own a bike shop and now he just does thing s out of his garage.. I have a ESR 310 kit with the trx 9 port. I think it is great. while drayton enterprises rebuilt and assembled my motor. This guy does really good work..