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I have read lots about the jetting on a uncorked 2011 CRF 230. I live in Kelowna British Columbia at 1200 feet above sea level. The baffle will be removed as will the snorkel. I've seen several threads on this issue and just want to check my assumptions before I proceed as I don't want to have an expensive lawn ornament. Mike Coes Dyno tests suggest a different combo than others and it appears many favour his opinion.

So my question are these ?

1) At this altitude is the combination of a 120 Main, 45 pilot and power up needle in the 4th position with 2 to 2.5 fuel screw turns a safe place to start.
2) is a 132 or 45 Main "leaner" than a 120 and 48 ? I think the stock is 108 yet a 120 is suggested....is that "richer" or "leaner" (presumably because the baffle is out...??)
3) how will I know if its too lean. Again I just dont want to blow the engine.
4) do these changes reduce the life of the engine or just amplify what it was intended to do like a governer on a golf cart?
5) Is the carb the same on the 2011 as the 2007 and other years ?

Sorry if this sound like a repeat Im new to this and just want to check with those who know.[/font]
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anyone?

The bigger the number jet the fatter it is the smaller the leaner it is. At 1200 ft. I would think the 120 main jet would be good the pilot jet would be good at a 48 at your elevation I would think. The pilot controls idle to part throttle. The main jet controls part throttle to wide open. The needle you would want would be the needle from a  2003-2005 model with the clip in the forth from the top notch. The power up needle would be better at sea level.

1) At this altitude is the combination of a 120 Main, 45 pilot and power up needle in the 4th position with 2 to 2.5 fuel screw turns a safe place to start.

Yes, start here. Except, start at 1.5 out on the fuel screw and don't go out more than 3 turns.


2) is a 132 or 45 Main "leaner" than a 120 and 48 ? I think the stock is 108 yet a 120 is suggested....is that "richer" or "leaner" (presumably because the baffle is out...??)

132 main is richer than 120.
45 pilot is leaner than 48.

120 is richer than 108 (bigger hole).

Ignore 132 and power-up comments; stick with stock needle and 120 main.  You should buy the '03-'05 needle for adjustability.


3) how will I know if its too lean. Again I just dont want to blow the engine.

You will not blow up the engine.  It won't be too lean.


4) do these changes reduce the life of the engine or just amplify what it was intended to do like a governer on a [size=1]golf[/size] cart?

These changes make the engine run cooler and deliver slightly more power because they change the jetting from too lean to just right.


5) Is the carb the same on the 2011 as the 2007 and other years ?

The carb body and most of the internal parts are the same, but the needle is different.

Check it out:
http://rickramsey.net/CRF230Fcarb.htm
Click on "Detailed carb pictures" and scroll down to the needle pictures.

Edited by ramz, 20 June 2012 - 05:08 PM.

Im running a 120main and 45 pilot now power is amazing, the highest Ive gone was 525 meters I found that my bike had a hard time idleing that high. I might not have my fuel screw out 2.5 turns cant remember what i set it at.

thanks. Please forgive my ignorance but aren't the power up and 03 -05 needle virtually interchangeable.  

ride-onn are you runnning a stock needle, 03-05 needle or power up needle????  

Am a hearing a 48 pilot might be better ??? I ordered a 45 and know they are cheap but can compensate with by adjusting fuel screw more?

I really appreciate your time and the info guys .

kred, on 20 June 2012 - 08:46 PM, said:

Yes - the needles are interchangeable.  One works a little better at lower elevations and one works a little better at higher elevations.  I don't have my Mike Coe notes with me here on the road but I will look it up when I get back home.  I believe Mike found the stock needle is better up high and the "Full Power" needle is better down low.

kred, on 20 June 2012 - 08:46 PM, said:

Every bike can be just a little bit different.  I have found most work best with the 45.  If you're over 2-1/2 turns out on the idle mixture screw you need a 48 pilot.  My bike works best with a 48 in the winter and a 45 during the hot summer.  To make things easier I usually keep the 48 and run a little less than 1/2 turn in the summer and a little more than 1-1/2 turns in the winter.

Edited by VortecCPI, 21 June 2012 - 03:08 AM.

Im sure you'll be fine with the 45 but vortec is right if your out more than 2.5 turns go up to the 48, you dont want your fuel screw to fall out. Im using my stock needle my bikes an 07. However im in canada so the needle so im pretty sure all years come with the "03-05" needle and d shaped fuel screw

That D-Shaped idle mixture screw can be a real pain.  You can make a tool using a piece of 1/4" OD copper tubing.  You'll have to turn the OD down just a bit on a grinder or lathe.  Then crimp a flat on the edge with needle nose pliers.  You can also replace it with a 2003-2005 version or cut a slot in it with a Dremel tool so you can use a small straight-blade driver.

Ah i forgot actually mine has the fuel screw that you just turn with a common screw driver.

So I put in the needle on the 4th groove. 120 main jet. 45 jet may work but if I have to screw out the fuel screw more than 21/2 turns I should bump up to a 48 to allow more adjustability and fuel flow.  I then adjust the fuel screw on a warm engine by cranking up idle, screw in until it almost stalls and screw out until it is at optimal position. in the area of 1.5 turns usually. Last but not least least I turn down the idle to a low idle.

have I missed anything....? Thanks for the tips.

Now you're cookin with grease. Grab the right grip and release the horses.

thanks a tonne man

thanks a tonne man

thanks a tonne man

Any Honda Service Manual will have a section on jetting for altitude and temperature.  Usually jet changes are not required until 5-6 thousand feet.
And some compensations can be done with the mixture screw and/or needle clip position.