250r experts. need some advice.

[threewheelin-feelin]

ok guys ive got a 85 250r. i currently have a ESR 310 kit with ESR reed block and reeds, 38mm A/S carb, ESR atc5 pipe and silencer, pump gas dome with trx9 porting. im running stock gear with stock swing arm and 20 inch dunlop rear tires. im also running stock air box with a k/n filter in it. it is a big difference in drag racing then the old setup but im trying to get a little more out of my set up. do any of you guys have any suggestions how to get a little more out of this set up with out a huge amount of money?

[Billy Golightly]

Spend some serious time and effort dialing in your carb. Buy $100 worth of main and pilot jets. With those kind of bolt ons you should have plenty of power unless its just not dialed in good with the carb or you have some other sort of a problem somewhere.

[250rRoostmaster]

^^Agreed^^

Are you running the air box lid and frame to air box intake tube as well? Those can restrict the R motors once they are built, these motors like airflow! But with your setup you should have plenty of power everywhere. How does it run?

[JasonB]

ya i have to agree with everyone in here. my 310 bike has the same basics you do (vforce3 reeds and a different pipe) and I was surprising people drag racing on mine. practice your launches and like Billy said go get some jets and play around. I use jetsrus.com for buying genuine kehein jets by the handful

[threewheelin-feelin]

i have stock air box with the lid on it. i have k/n filter in side. i believe i have it at a 170 main jet and whatever the stock pilot jet is on the a/s carb. the carb had a 185 main in it to start with if i remember correctly and was fouling plugs like crazy. once i got it down to a 170 i hardly ever have to change the plug now. you guys think i should get rid of the air box? and go back with a bigger main jet?

[Billy Golightly]

You might be able to go way leaner than the 170, but everyones individual setups is different. I typically run around a 158 in mine. What does your plug look like, pics?

Did ya do an airleak test when you put it together, does it use any transmission oil ever?

Making it breathe through just the little tiny air inlet while the lid is on isn't really helping any, but if the conditions necessitate it, then leave it on of course. Especially with a K&N filter.

[Red Rider]

you guys think i should get rid of the air box? and go back with a bigger main jet?I don't believe in ditching the airbox completely (others here on the boards swear by it though), but I would at least venitilate the airbox lid substantially, or remove it altogether.

[threewheelin-feelin]

You might be able to go way leaner than the 170, but everyones individual setups is different. I typically run around a 158 in mine. What does your plug look like, pics?

Did ya do an airleak test when you put it together, does it use any transmission oil ever?

Making it breathe through just the little tiny air inlet while the lid is on isn't really helping any, but if the conditions necessitate it, then leave it on of course. Especially with a K&N filter.

doesnt use any tranny fluid. plug is black when i change it

[Billy Golightly]

If its black you can lean it out some more.

[threewheelin-feelin]

If its black you can lean it out some more.

think i should leave it alone and try eliminating the airbox first? i kinda think i want to do that anyway

[Billy Golightly]

You can but thats going to be a much bigger change that'll effect many different facets of the jetting, but sure, try it.


Its gotta be just not dialed in right, that kind of a setup should be able to really snap you and your neck back hard

[RIDE-RED 250r]

If you need to retain some protection from water and whatnot, I suggest leaving the lid on the airbox but removing the tube connecting the airbox to the frame backbone. Thats what I have done and my 350 seems to breathe quite well yet is still fairly protected from water ingestion. It needs a 190 main and a 50 pilot.

I would bet that along with the carb needing more tuning as suggested by Billy, Jason and Red rider, running the full airbox with lid and connecting tube is probably holding you back as well...

[JasonB]

I run a 170 main and 50 pilot in my carb for the 310, but I run airbox with no lid. 158 sounds wayyyy close to lean for my tastes! I may try going lower and play with my own jetting now though lol got me thinking. I like the airbox for protection against any condition I ride in, kinda nerve racking to get stuck in wet conditions with a pod filter!

[deathman53]

my take with this is to remove the 310 (really 293) cylinder, send it to bdt, c-leigh, halls for a Good port job, remove air box lid, get a 2001 cr250 ignition and be prepared to hold on very tight. If you want to keep lights, you can service Hondas cr500 digital ignition. I had a esr330, then got a lrd295pv, holy cow it was much more powerful. Esr's porting is decent at best

[threewheelin-feelin]

my take with this is to remove the 310 (really 293) cylinder, send it to bdt, c-leigh, halls for a Good port job, remove air box lid, get a 2001 cr250 ignition and be prepared to hold on very tight. If you want to keep lights, you can service Hondas cr500 digital ignition. I had a esr330, then got a lrd295pv, holy cow it was much more powerful. Esr's porting is decent at best

yes i know ESR porting isnt great. but i really like there cylinders. i have thought of sending it off for a better port job strictly for drag racing but its going to be awhile before i do that. does it make a difference that it has already been ported? and lights are a must for me. also i have no problem with completely eliminating the air box. the only time i ride this bike is on the drag strip. i also plan to stretch it at some point. launching is probably my biggest problem

[Billy Golightly]

Not discouraging the additional port work by any of those mentioned, but please make sure your carb is dialed in awesome before you spend any more money on other stuff. You will be very surprised what lurks in that motor if its dialed in

[JasonB]

Like Billy said, play with the jetting before you start dropping money on it. You may find you are happy as is with some tuning. Also, I am looking to probably sell my +6 swinger off the bike in my sig this summer if you are interested in stretching your R out this year

[threewheelin-feelin]

billy i plan on doing that first. i am going to eliminate the air box and run just a k&n filter on the carb then mess with jetting. jason i was really thinking about going +10 or 12 but i may be interested in yours. will it work on the 85 and how much do you think you would want for it? also im thinking gearing and tires will be another thing to mess with

[RIDE-RED 250r]

I have Eddies mid-top porting on my 350 and I'm here to tell ya, it aint slow!

[threewheelin-feelin]

I have Eddies mid-top porting on my 350 and I'm here to tell ya, it aint slow!

my 310 isnt slow. i have the trx9 mid-top porting as well. it runs very well and i have beatin many 450s with it. im just trying to figure out ways to optimize what i have. when im done i want it to be nothing but a drag bike