[VortecCPI]

For those of you still wondering whether or not to spend the time to covert from Honda's Technical Bulletin specs to Mike Coes' specs here is my take.

I initially setup my 2009 230 with the Honda-specified needle (notch #3) and 132 main jet along with a 45 pilot and removal of intake and exhaust baffles. It was much better than stock but still too lean on the bottom (forever to warm up and popping on decel) and too rich on top. I installed a 48 pilot and 125 main and was very pleased with the results.

So how did I determine that Mike’s specs are far better than Honda’s you ask?

My buddy rides a 1997 XR250 freshly rebuilt with a 32mm flat slide from XR’s Only and an FMF pipe and we also have a 2004 XR250 with 48/135 jets and all baffles removed. The 1997 was slightly stronger than the 2004 with the stock carb and noticeably stronger with the flat slide.

I weigh 150 pounds without any gear and my buddy weighs 195 pounds without any gear. With the Honda-specified jetting I could NEVER keep up with him from a stop or on the straights. Last weekend I installed the 2003-2005 needle (notch #4) with a 120 main and could instantly tell the carb was now spot on. It used to have a weird spot from ¾ to full throttle and never really pulled at the top. I just figured it was all I could expect from an old two-valve design. WRONG – It was due to bad metering and it now screams on the top end.

We went to Carolina Adventure World last weekend and lined our bikes up on the dirt dragstrip for a test. I’ve got to be honest and admit I expected the runs to be a joke but I figured I’d give it a shot just for fun. Even with the 45 less pounds who could expect a two-valve 230 to give a four-valve 250 a run for its money? I took off in first gear on the first run and he maintained a one-bike length lead the entire way but he did NOT pull away from me like he always did in the past. For the next run I used a second-gear hole-shot and kept in front by a small margin the entire length. I did the same again on the third run and kept in front again the entire length. All I can say is WOW and my buddy sure was impressed and a bit disappointed at the same time.

FYI both bikes have brand new tires and I am running 13/50 sprockets and he is running 13/50 sprockets. My 230 is bone stock except for 3/4" of fork spring spacers for 2 3/8" sag and 3 turns on the rear shock collar for 3" sag. Our top speed at the end of the dragstrip was 52 MPH. Once again, he was carrying an extra 45 pounds. I am SURE the XR would easily overtake me given enough space and distance but I really don’t care. How often do you hit 52 MPH in the woods? How about never.

On the trails the extra top end available at the top of the gears is amazing. The places where I used to shift up a gear (because it just no longer pulled hard) are now easily conquered at the top of one lower gear. These are the places where the XR250 would always gain distance on me and that is no longer the case.

If any of you have any doubts about Mike Coe’s dyno work I suggest you line up against someone running his jetting recommendations and be prepared for a wicked beating. My 230 is now like a whole new bike and I am no longer being left behind the XR250s!

Spend the money and the time and go do it!

Final results: 48 pilot with 120 main and 03-05 needle at #4 at sea level. See the chart below for variations on Mike's jetting:

Temp Mult. Pilot Main
000F 1.08 52 129
010F 1.07 51 128
020F 1.06 51 127
030F 1.04 50 125
040F 1.03 50 124
050F 1.02 49 123
060F 1.01 49 121
070F 1.00 48 120
080F 0.99 47 119
090F 0.98 47 117
100F 0.97 46 116
110F 0.96 46 115
120F 0.94 45 113

Alt. Mult. Pilot Main
0000 1.00 48 120
0500 0.99 48 119
1000 0.99 47 118
1500 0.98 47 118
2000 0.97 47 117
2500 0.97 46 116
3000 0.96 46 115
3500 0.95 46 114
4000 0.95 45 113
4500 0.94 45 113
5000 0.93 45 112
5500 0.92 44 111
6000 0.92 44 110
6500 0.91 44 109
7000 0.90 43 108
7500 0.90 43 108
8000 0.89 43 107
8500 0.88 42 106
9000 0.88 42 105
9500 0.87 42 104

[amaviper]

So was this your final set up?

48 pilot
120 main
power up needle in the 4th position from the top

[etuke]

i have been running the 48p and 120m with the needle in the 4th pos.I found it fouled up the plug quickly,turning it black.It would hesitate at full throttle and had little acceleration high in the rpm.I have since put the needle at 3rd pos and the hisitation is gone but not a big puller in the high rpms,I haven't checked the plug to see if it was still black.I have a 45p ordered but I may keep the 48 if the plug looks ok now.

[VortecCPI]

So was this your final set up?

48 pilot
120 main
power up needle in the 4th position from the top

Exactly that but the needle was an 03-05, NOT the Power-Up needle - Throw that thing in the garbage. The Power-Up needle has a different taper than the 03-05 needle and I found it is too lean at 3/4 to 7/8 throttle. It caused a lack of power near the top end which was only aggravated by the too-rich 125 main I was using. The result is a "flattening" of power at the top end. Mike's specs make the transition from 3/4 to full throttle dead on.

The dragstrip proved Mike's results to me beyond ANY doubt. I could NEVER keep up with that damn XR250 with the Power-Up jetting. I believe I will be able to walk him when I install the XR250 carb I am working on now.

[VortecCPI]

i have been running the 48p and 120m with the needle in the 4th pos.I found it fouled up the plug quickly,turning it black.It would hesitate at full throttle and had little acceleration high in the rpm.I have since put the needle at 3rd pos and the hisitation is gone but not a big puller in the high rpms,I haven't checked the plug to see if it was still black.I have a 45p ordered but I may keep the 48 if the plug looks ok now.

My plug still burns a very, very light tan and runs fantastic at every throttle position in every gear in every situation. FYI - I ride at sea level.

You might want to check your float level if you're running too rich with the same jetting. I attach a clear line to the float bowl drain, bring it up past the top of the carb and open the float bowl drain screw. The fuel will climb up the clear line to the position of the level in the bowl. You can then easily and quickly do a sanity check on your float level. It should be near the gasket on the float bowl when the bike is straight up.

My buddy's XR250 ran really rich with 48/135 jetting and the cause was a worn needle and needle jet. You might want to check your needle jet too.

[VortecCPI]

I should have thrown that 921 needle in the garbage but I really wanted to find out for myself. I used to work in a speed shop and I rejetted MANY Holleys and Quadra-Jets for both the street and the strip. I have also done quite a few bikes along the way too. This was not my first rodeo so I figured why not REALLY see what's going on. The bottom line is that Mike Coe spent hours on a dyno and it is just foolish for us to question his work - PERIOD.

[etuke]

I have an 07 and it came allready jetted,I just added the 120M,I know the needle has the 5 different positions but it may be the power up needle.The flatening you described is exactly what is going on with mine and it happens at 3/4 throttle,it just seems to run out of acceleration.Is there any markings on the needle to determine which 1 I have?

EDIT: i just looked up the part #'s and they are the same for the 05 and 07.

[VortecCPI]

I have an 07 and it came allready jetted,I just added the 120M,I know the needle has the 5 different positions but it may be the power up needle.The flatening you described is exactly what is going on with mine and it happens at 3/4 throttle,it just seems to run out of acceleration.Is there any markings on the needle to determine which 1 I have?

The 03-05 needle is p/n 16012-KPS-901 marked C39A
The 06-09 needle is p/n 16012-KPS-731 marked C83A
The Power-Up needle is p/n 16012-KPS-921 marked C30FF

The 03-05 and 06-09 needles look very much the same but the 07-09 has only two clip positions equal to #2 and #3 on the 03-05 needle.

You will not believe how well the 230 pulls on top after you get the 03-05 needle installed at #4. I always thought the top end was "dull" due to the two-valve head design - Boy, was I wrong!

[etuke]

I have an 07 and it came allready jetted,I just added the 120M,I know the needle has the 5 different positions but it may be the power up needle.The flatening you described is exactly what is going on with mine and it happens at 3/4 throttle,it just seems to run out of acceleration.Is there any markings on the needle to determine which 1 I have?

The 03-05 needle is p/n 16012-KPS-901 marked C39A
The 06-09 needle is p/n 16012-KPS-731 marked C83A
The Power-Up needle is p/n 16012-KPS-921 marked C30FF

The 03-05 and 06-09 needles look very much the same but the 07-09 has only two clip positions equal to #2 and #3 on the 03-05 needle.

You will not believe how well the 230 pulls on top after you get the 03-05 needle installed at #4. I always thought the top end was "dull" due to the two-valve head design - Boy, was I wrong!

well I'm off to check the needle,Thanks for the info,will let you know what it turns up as.

[etuke]

well mine has the proper needle from the 03-05,have to have it in the middle clip or top end is even worse.Temps may be affecting it some,its only been 3-6 degrees Celcius here.On a bright note the plug color has improved greatly,I'm running a dark tan color now instead of dark black.

[VortecCPI]

well mine has the proper needle from the 03-05,have to have it in the middle clip or top end is even worse.Temps may be affecting it some,its only been 3-6 degrees Celcius here.On a bright note the plug color has improved greatly,I'm running a dark tan color now instead of dark black.

Out of curiosity, what is your altitude?

[etuke]

sea level

[dsrpilot]

Great info. can't wait to try it out...

[heybuddy1901]

I should have thrown that 921 needle in the garbage but I really wanted to find out for myself. I used to work in a speed shop and I rejetted MANY Holleys and Quadra-Jets for both the street and the strip. I have also done quite a few bikes along the way too. This was not my first rodeo so I figured why not REALLY see what's going on. The bottom line is that Mike Coe spent hours on a dyno and it is just foolish for us to question his work - PERIOD.

you know whats funny, if you go on thumpertalk and look at his first few posts in the 230 forum and no one belived him haha

[VortecCPI]

I must admit I was a bit quilty too. It wasn't that I didn't believe him - It was that I couldn't believe most people didn't jet to his specs and nobody provided good feedback when they did. Once again - I was BLOWN AWAY by the results at the dragstrip and so was my buddy on his XR250! I'm still smiling right now...