Need help with jet sizes on R

[250r'en +TCB]

I have to admit, if there is one area I lack knowlage in when it comes to engines it's jet sizes......:wondering I really do need to have some knowlagable person give me a lesson someday......:rolleyes:
Anyway I'm buying a 38mm Mikuni TMX carb from BigGreenMachine and I need somebody to tell me what to jet my R to. The R is just piped. What size jets and where can I buy them???

Thanks guys! -Devin:beer

[BigGreenMachine]

http://justkdx.dirtrider.net/carbtuning.html

[nouseforaname90]

I'd personally wait until you get the 310 kit to put the 38mm on.. you won't get much of a gain over a 34mm carb if you only have a piped R, and you will have to rejet the 38mm twice instead of once..

[250r'en +TCB]

Well even if I get a little power gain, I mine as well.....
What else could I do to my R before I get the 310 kit to boost power? Reeds proubly right??? Anyway can anyone tell me the correct size jets for this and where to get them?
-Devin

[nate b]

I dont run a mikuni but you can get the jets at any dealership, or dennis kirk etc. nobody is going to be able to give you the exact size to run, but I'm sure someone will get you close, then buy 3 sizes larger and smaller and start doing plug chops. right that jet size down along with the temp outside, then when fall comes do it again,and again in winter and you should be all set.

NATE

[AZ250R]

I run an old 80s-something 38mm round Mikuni and haven't had it appart in forever to even know for sure what settings its at. I do know that I've changed out the main for altitude a few times but run a 310 mostly from 1,400 feet and down. Needle clip is somewhere near middle, but I think it has 4 settings so one of the 2 middle ones if I'm not mistaken. All I know is that I've rode piped 250Rs with stock carbs and mine with the 38 and mine has alot more punch throughout the range! I have a set of Boysen reeds that I put in and ran for like a year then switched to V-Force IIs and that made a noticable difference too.

I've got a like 1/4 inch spacer and my old Boysen reeds that I'd be willing to part with for like $10 if ya really wanted to experament with that... probably a few extra main jets for ya too, but your altitude must be more than Phoenix AZ.

[BigGreenMachine]

He is buying a 38 mm TMX from me. I have a 300 main put in it, should stick the 50pilot in too instead of the 40. Anyone have any other base settings as far as liquid R's go for a 38mm carb?