Jetting specs for 03 RM250

[mxldy]

Does any one have or know where I can obtain some recommended jetting specs for an 03 RM250. Will be riding MX in the North and Southeast. Thanks

 

[Pacho]

Stock jetting is too rich. Did you get a spare part kit with your bike? There you will find several main jets. Here in Southern California I am using the smallest one (175) and moved the needle clip to the second position (4th is stock). 1.5 turns on the air as well. Jetting feels almost perfect for MX.

 

[02'Cr Rider]

Pacho, What do you think of the bikes power output? I'm looking at getting a 03 RM250,and looking for a bike with good bottom end.How's the handling also.

Thanks,

 

[Pacho]

There is a 250 shootout in the latest TransworldMX magazine and I think their comments about the RM 250 are right on:

"Test riders raved about the plush suspension action and the bike's uncanny ability to carve an inside line, no matter how tricky the corner. The Suzuki has a light feel both in the air and on the ground", "As often as riders raved about the RM 250's tight track prowess, they commented that at speed in the rough, things got a little sketchy".

Regarding the engine: "Power-wise, the RM 250 is plenty fast and drew good reviews from testers. Low-end power is good, mid-range is great, but top-end overrev is average. Riders who like to rev their bikes out in each gear will struggle a bit with the RM, as it works best when shifted just before the upper echelons of the RPM range".

I am coming from a '02 CR 250 and the transition was initially tricky in terms of handling but after a few rides I loved the RM. The engine is much forgiving and all the concentration I used to put on my CR's motor I now put on my riding (turns, jumps, positioning, etc) and this has helped me to significantly improve lap times.

 

[02'Cr Rider]

I too have a 02 cr250 and was looking at getting a new rm250.Is it twitchy?Cause I ride trails mostly with lots of rocks.Can you compare the cr and rm for me.

Thanks

 

[Pacho]

I ride MX only and the bike gets a bit twitchy in the rougher parts of the track. This is the trade-off of having incredible cornering traits. The RM's handling is not as forgiving as the CR's and if you get lazy the bike will catch you off guard (I went over the handlebars on my second ride!). I guess this would be more critical in trail riding. However the RM is a faster bike for me.

'02 CR 250: Top-end power only, stable yet good carver, trustable handling.

'03 RM 250: Lots of low & mid range power, bit twitchy, amazing carver, nervous handling at higher speeds.

 

[02'Cr Rider]

Thanks for the input on the RM250.I've read somewhere to lower the forks 5mm to help the stableness.They said it helps big time!!!!!

 

[Nevada Sixx]

what does everyone mean by rm being nervous at high speeds? and has anyone lowered to forks that can give us a ride report to see if it cured a problem?

 

[gbs1]

Try a
N3WK in the 2nd clip position
170 main jet
45 pilot jet

The RM is nervous at speed because of the frame geometry, it is a trade off, what makes it turn well causes it to be twitchy. A good example was the 93 Honda famous for being a great turner but had head shake at speed.

 

[los36]

I have an 02 RM and I have posted several times to lower the forks 5mm.
It makes a big difference. There is a long straight followed by a 4th gear, wide-open uphill triple jump at my local track. The straight always gets whooped out and chopped up. The first few times I rode my RM there, things would get a bit scary as the face of that jump approached and the front end was dancing around.
From prior experience on other bikes, I tried dropping the forks down a few mm. It made a big difference and it was especially noticeable on that part of the track. It still tuns as well, also. Maybe if I was faster (I'm a top-5 novice), I would be able to tell the difference in the turning, but it still turns on a dime, in my book. I have not touched my forks since.
I believe that the 03 has the same frame and geometry as the 02. Try it out!

 

[tonyromero]

Hmm. My new RM will be in this week. I'm in Miami, FL. So you think I should need to lean out the jetting too? Thats strange. If stock jetting is too rich at sea level then it probably would not work anywhere. My old DRZ came way to lean from the factory and I ended up going from a 142MJ to a 165 with great results. Does the So. CA. guy ride at sea level or up in the hills? Any guys out there ride the RM at sea level?

 

[gbs1]

toneyromero, the N3WK, 170 main, and 45 pilot should work fine for you
if that is still to fat for you in Florida can go to a 168 main or switch to a N3YK needle

 

[tonyromero]

N3WK needle? 2nd clip? 170 main and 45 pilot.

Is this the stock needle? does it come in the part kit or do I need to order one? What is the stock jetting? Thanks for the tips.

 

[gbs1]

Tonyromero, No this is not the stock needle you will have to order one. 2nd clip position
Sorry for the late response, I've been out of town.

 

[Jawsrm134]

Im trying a 48 pilot (slow jet) and dropping the needle 1 notch.

GBS 1 ?? Did your bike come with a 50 pilot stock and did you try a 48 prior to the 45?

 

[tmoran]

Thanks, it is great to get some input on the jetting specs for the 03 RM 250. I am a long time KX racer and this is my first RM and I absolutely love this machine. The seat to tank transition allows me to get in any position I need to make the bike work for any situation. The low-mid power and suspension is awesome, however, it will raise the hairs on the back of your neck if you do not pay attention. I would recommend this bike to anyone!

 

[gbs1]

jawsrm134,
I did it was still too rich off the bottom and the needle jet is a big culprit here too. the main and needle is to fat.(rich) I think this is some of the problems that the RM riders are having with that slow response and loading up. My last plug reading was the proper tan color.

 

[Jawsrm134]

Gbs1

So you would reccomend getting the needle also? I havent ridden it that much yet, I want to get the pilot system working then on to the main and midrange. Thanks for the info.

Did you buy your needle from the dealer or online? I found a place called carbparts.com specializing in Keihin and Mikuni carbs. Ill try your reccomendations. 45, 170, n3wk needlke second clip. Is that from the bottom or top.

 

[gbs1]

2nd position from the top. I just ordered my needle tthrough a dealer but the carbparts.com should be just fine oem is oem

remember each jet circuit over laps each other at a particular throttle position, So I would recommend at least changing your main and needle position with the pilot jet to get a little better response as the pilot transitions to the main jet. BOL

 

[tonyromero]

OK! I ordered up the parts I need to do all this. I think stock main is 190, isn't a 170 a big drop for me being at sea level? Why would the factory jet them so rich that they don't work at sea level? if its too rich for me in FL. it will be too rich for anyone. Anyway, I will do the mods and hopefully start to enjoy my bike as it has been nothing but a hassle thus far. I was looking long and hard at an 03' WR250, straight gas , good suspension and electric start are enticing. I will give the RM some time though.

 

[tonyromero]

carbparts.com doesn't sell those needles. I talked to a tech guy there and he advised against going from a 190 stock to a 170. he suggested I do it in increments on the main. I'm going to try a 45 pilot, lower the stock needle a clip and try a 185 main. I'll report my findings. Incidently, he said in a few weeks he will have jetting specs on the RM after they do their own research.

 

[Jawsrm134]

Great Tony thanks for the heads up on carbparts.com, I am dooing the same thing as you but 180 main. By the way did you try what I said and did it work?

Mark

 

[tonyromero]

Not yet. I'm going to figure it all out this Saturday. New plug, new jetting and proper start technique. I'll post how it rides. I may end up loving the bike once it works right.

 

[TRAIL]

All bikes are fun once you get them dialed in alittle bit

 

[gbs1]

My bike was real blubbery had very poor response and tons of spooge. My plug reading says it is ok and I run it pretty hard. I am at sea level too, but your humidity is a bit higher in Florida which will effect the jetting too.
I will take a second look at my main I don't remember if it was a 190, thought is was a 180? I do know it had a 50 pilot.
let us know how your setting work out.