2003 RM 250 Jetting Questions

T

tylerdb

6.5 Slide
165 Main
45 Pilot
JD Jet Kit
Elevation ~1500 ft.
~ 70 Farenheight
~ 60% Humidity

Bought a JD jet kit and cant seem to get my jetting anywhere close for this bike. It has a new top and bottom end, float adjusted, carb cleaned, reeds cleaned and adjusted.

Bike has power right off the bottom (can pull the front tire up easy), but at around 1/8 throttle to 1/2. I cant get any sort of power and it is so boggy and smokes a ton until about 1/2 throttle then takes off after that.

I've tried both needles in the jet kit on every clip level and can't get it close.

What should I be looking at next?
 
SRAD97750

SRAD97750

Moderator
Staff member
tylerdb:
...but at around 1/8 throttle to 1/2.
What should I be looking at next?
Click to expand...
That range of throttle is 100% controlled by
Float Setting
Idle Jet
Idle Mixture screw
Needle
In that order.
I would start one by one and I'm sure it'll clean up.
You are rich in that range so you will be leaning these. Each one compounds on the next if they are incorrect.
-BIG DAN:thumb:
 
Mihylo33

Mihylo33

tylerdb:
6.5 Slide
165 Main
45 Pilot
JD Jet Kit
Elevation ~1500 ft.
~ 70 Farenheight
~ 60% Humidity

Bought a JD jet kit and cant seem to get my jetting anywhere close for this bike. It has a new top and bottom end, float adjusted, carb cleaned, reeds cleaned and adjusted.

Bike has power right off the bottom (can pull the front tire up easy), but at around 1/8 throttle to 1/2. I cant get any sort of power and it is so boggy and smokes a ton until about 1/2 throttle then takes off after that.

I've tried both needles in the jet kit on every clip level and can't get it close.

What should I be looking at next?
Click to expand...


Drop the pilot down 1 to I think a 42.5. Red needle with the middle clip air screw at 2 turns out. Mix at 32:1 and premium and that should clean it up.
 
jackson409

jackson409

not sure if the 03 has the choke knob adjustment. My 01 has it. You'll need to set that as well if it does. I have mine set at 14 clicks out. Turn it all the way clockwise until it stops and then back it out counter clockwise 14 clicks.
 
jackson409

jackson409

PALMER84ONE:
Choke knob adjustment? I'd just strangle it and be done!
Click to expand...
Nah it may seem it just adds more to the jetting but actually it allows me to fine tune mine by clicking up or down on the trial when I ride. I dont fuck around with constent jetting like the anal mutha fuckas do changing out jets. Run what cha brung and fine tune it on the trail with just a few clicks up or down.
 
T

tylerdb

So far i used the red needle on the middle slot with a 45 pilot, 165 main and air screw 2 turns out. All this after re-setting the float and its no better, still very boggy.

The JD Jet kit says to use a 45 pilot, could one size down really help this much?
 
Mihylo33

Mihylo33

tylerdb:
So far i used the red needle on the middle slot with a 45 pilot, 165 main and air screw 2 turns out. All this after re-setting the float and its no better, still very boggy.

The JD Jet kit says to use a 45 pilot, could one size down really help this much?
Click to expand...


It could. I tried the JD kit on my 06. Waste of money IMO. I thought it would make my life easier for racing but I still have to tune. The needles however are a work of art. I had to drop my jets on my rm to get it to really pul hard. I'm at sea level to 1500asl. I also had to switch to race gas blend to really get perfect response out of it.
 
T

tylerdb

Small update:
165 Main
45 Pilot
Red JD Jet needle 2nd clip from the top
Air/Fuel screw at 2 3/4 turns out
Amsoil 40:1 with Premium

I got it to clean up quite a bit but it crackles a lot when riding in 3rd gear with the throttle barely open. It gets better as get past 1/2 to WOT.

Ordered a 42 pilot for it and will see if that makes it any better.

Thanks again guys!
 
jackson409

jackson409

tylerdb:
Small update:
165 Main
45 Pilot
Red JD Jet needle 2nd clip from the top
Air/Fuel screw at 2 3/4 turns out
Amsoil 40:1 with Premium

I got it to clean up quite a bit but it crackles a lot when riding in 3rd gear with the throttle barely open. It gets better as get past 1/2 to WOT.

Ordered a 42 pilot for it and will see if that makes it any better.

Thanks again guys!
Click to expand...
Check your choke knob adjustment.
 
T

tylerdb

Mihylo33:
Save your $$$ and go buy some yamalube and mix at 30:1. Your bike will run better and love you for it. Trust me.
Click to expand...

I'll definitely get some yamalube, i used to run it in my KTM and liked it. I had heard good things about amsoil so i thought id give it a try.
 
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