[1988 250r]

I want to buy a 310 kit probaly from ESR, because they are so afordable. I know not everyone is a fan of ESR, I dont want to get in to that. I just purchased a 39mm Mikuni carb from ebay for this project. I really want to know if i need to get a bigger intake and boot. Any advise for performance that wont brake my budget would be highly appreciated. Thank you for reading.

 

[Victork]

Oem boot fits if you heat it. Most say boil it but I used a torch while it was on my bike carefully so nothing gets burned.

 

[motofool250r]

Heres the deal, if you port your OEM cylinder it will be faster then the ESR310(this is actually a 293cc motor) basically out to the last bore of the stock jugg.

so if your gonna blow 500$ on a cylinder your not gonna see a lot of gain without a full pro port job 450$ now your into 1000$ with nothing done in the bottom end.

so think about where your going with the motor.

 

[1988 250r]

thanks for the advise im going to wait and think about it till i purchase it.

 

[motofool250r]

if your wanting to go bigbore, atleast step up to the 330cc kit and if your crank needs rebuilt good time for a +4mm crank (344cc)

just some ideas and thoughts from someone whos got a few big bores.

 

[1988 250r]

what if i ported the 310 cylinder ?

 

[joshuabuilt]

I too was looking into esr as an option. I was thinking of doing the 370 stroker with a power valve.. what do you think about that?
I dont mind spending the money now cause I have watched my buddy do little things to his banchee at a time and blow a ton of money by doing that then finally doing the right setup the first time out...
good luck on ur findings 88250r im in the same boat

 

[gingerbreadman]

i have a 330 esr kit runs good stroked and either dome u have in the head youll still need race gas the pump dome put to much heat and stress on the motor

 

[1988 250r]

yeah i use race gas in my r right now.

 

[rk88r]

You could run the 310 kit for a season and then budget a fresh piston/bore/and port. If you can swing it starting out with a sphynx would be better.