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CRF230F exhaust Qs

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I just bought 2 150's for my boys and a 230 for me.

They are new riders (11 & 14) and love theirs. I like my 230, but find it wimpy as I recall my old CR500. I could ride a wheelie 1/4 mile with that thing.

We're in Westchester County, NY and ride in some open land behind our home. We also take day trips to more open places, locally and we go to ME a few times a year.

I downsized all our sprockets to 12 teeth, as we're riding in really tight spaces. Most of the time, I was in 1st and 2nd. Now, I'm using 3rd more. I also like the extra grunt. The front wheel comes up, but I can't hold if very long. I don't think we'll miss the top end, even up in ME.

Next, I'd like to uncork the 230. I removed the baffle, but decided it made too much noise for my back yard. Since we trailer to open spaces, I'd like an adjustable setup. I've been reading lots of info, but can't find an answer to my Qs.

1. If I open the air box, remove or drill out the baffle and do the hop-up kit, can I run the bike with a stock baffle from time to time? I'm talking about riding very short jaunts, say 30min max. I figure the worst I can do is foul a plug, right?

2. There's plenty of talk about jetting, but very little about how you determine how the bike is running? Spark plug color, idle, throttle response and ??

I was pretty close to picking up an X last week, but don't want the extra maintenance. I haven't read anything leading me to think there's a better choice for power, ridability and easy maintenance.

Thanks in Advance.

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It seems to be accepted wisdom that these bikes are jetted too lean from the factory in order to meet CA emissions standards and that they run better with rejetting and uncorking. I drilled holes in my baffle in order to free up the breathing without the loud noise of running baffle-less.

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AS I said, I'm interested in rejetting my bike, but can't find any info on how to tell where I'm at, other than "just do this" advice.

Now this is the kind of info I'm looking for:

The easiest way to determine if you are jetted properly is to do a plug check for each "range" of the carb.

There are three ranges to adjust in the carb.

Low speed: Is off idle to 1/4 throttle position. The pilot jet (is inside the carb float bowl and is removable to adjust the mixture by changing the jet to a smaller or larger number size) or fuel screw found under the carb outside between the float bowl and the intake manifold.

The smaller number on the jet = a leaner mixture. The bigger number on the jet = a richer mixture. The fuel screw turned OUT is richer turned IN is leaner.

Old time round slide carbs use an air screw (on the outside side of the carb) turning the screw IN richens the mixture and OUT leans the mixture. The air screw is NOT common anymore these days.

Mid range: Is adjusted by the needle clip and is 1/4 to 3/4 throttle position.

There are slots on the needle where a clip can be moved up or down to change the mixture. The top position on the needle is leanest (letting the needle stay lower in the bore of the needle jet that it fits into. The lowest position on the needle is the richest letting the needle stay higher in the needle jet bore.

Top end: 3/4 to wide open throttle is the main jet. It is a removable jet in the float bowl. Just like the pilot jet, it is numbered and the bigger number is richer the smaller is leaner.

AFTER, he goes on to describe how he installs a new plug then rides the bike a short distance in the prescribed range. He hits the kill switch while maintaining the throttle position. Following that, he removes and reads the plug. This sounds tedious and subjective.

spark plug reading:


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I have a complete stock header and can if anyone is interested with about 3 to 4 hours of use. But only willing to sell as a complete unit, PM if interested.

You can easily get a power up kit for this bike from your local stealer or online by searching for the CRF230F Honda Power Up Kit. This will allow you to swap out your needle and main jet. And like the others have said, you will want to open up the baffle...

By the way, this is a good general guide on plug color!


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Thanks Malindor! Great info.

I just ordered the power-up kit for the 230 yesterday. I'm concentrating on the 230 'cause my boys on their 150's are still learning how to ride and not pushing their machines as of yet. If my research is correct:

I can rejet totally stock bikes and still have some gains. Generally, the bikes come lean and I can drop the needle and increase the main jet to fix that.


I can remove the snorkle and drill out my baffle(for better flow without baffle-less noise levels) and install the power-up kit, which is the full power needle and the main jet.


I also read a blip that the pilot jet can be changed for better off throttle performance. Does this only apply to the modded + power-up bikes or not?

Note: I want to install a pre-screen on the top of the airbox to keep out the biggest crap. I've had the seats off and there's lots of crap under there. I have some really course foam which will keep this stuff out while not restricting any flow whatsoever.

What's the best filter setup? I just bought one on-line and opted NOT to install it. It has no grommet around the center post, so you can actually see thru the space. Defective product IMHO. I checked out BBR and I'm sure K&N has something out there.


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My new 09 CRF230f took several minutes to warm up using the choke. I installed a larger piolet jet (45) and that problem is solved.

From reading the sticky post about re-jetting a 230, it seems that the power up needle is not as good as the stock needle from '03 to '05 with the adjustable clip in the 4th position. I replaced mine with this older needle, but while doing the switch, I saw that I could have simply reused the stock non-adjustable '09 needle and put some small washers under the clip to raise it up that way.

After removing the intake snorkle, I used a piece of woman's nylon stocking over the unmodified opening and held it on with an elastic band, to keep out larger stuff. Window screen would work too.

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I tried both the "Power-Up" needle and the 2003-2005 needle and I preferred the 2003-2005 needle. You can read about the results here: https://thumpertalk.com/forum/showpost.php?p=9314420&postcount=333

Below is an excerpt from Mike Coe regarding the two needles:

"This is what I recommend for your bike and all others with stock engine with exhaust baffle and airbox snorkel removed. I ride my stock bike from 0 - 6500+ elevation with no changes in jetting between the desert and mountains.

120 main jet (used to be 132)

45 pilot jet

Stock needle with clip in fourth groove from the top

Accessory needle with clip in fourth groove from the top.

I have found that for low elevation riding, as in the desert, the "power-up" needle adds a touch better performance, but looses that same touch when riding in higher elevations of 4000 and up.

So when I know I am headed for the hills, which is 95% of the time, I use the stock needle. These are my opinions from testing back to back. Even though the "power-up" needle looks significantly different than the stock needle, especially at the small end, the actual working "taper" is very very close. The difference is very slight, and if you are not real sensitive to jetting and how it affects the way your engine runs, you may not even be able to tell the difference!! The most important change in all of this is to install the larger main jet if you have removed the airbox "snorkel", and to lower the clip on the needle to the fourth groove. I feel the installation of the 45 pilot jet is of second importance, but you will get good results at the elevations you posted with the stock 42 and the fuel screw out to 2.5-3 turns. DO NOT turn it out beyond 3 full turns from fully seated !

I hope this gets you going and these settings should put you right in the ballpark.

The needle marked C30F is the Honda "Full-Power" needle for the CRF230. All needle's come with a matching needle jet, as a set, from Honda. You can not purchase them seperately. The needle jet is the same for these two needles, so you do not need to change them out if you got one with your needle and jet purchase."

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Great info guys, thanks!

I'm gonna stay stock with snorkle removed and baffle modded. Sounds like I can return the $45 power-up kit, use the stock needle/jet and just buy a main and pilot jet.


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