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230 Jetting Q for Coeshow

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I found the altitude compensation chart a few days ago (although can't find it now) and saw that for my altitude...I live at 4000ft and will be riding between 3000 and 5000 ft....it said .96 on the chart. I assume that means I'd need jets 4% less than the jetting you recommended. I have main jets of 108, 110, 115, and 120 on hand. I only have the stock needle and pilot jet. I also noticed that you changed your recommended 132 main to a 120 for best power, so looks like I'm good on the main. From memory, you recommend the 45 pilot jet and the power-up needle. I haven't seen the designator for that particular needle written anywhere though. What is the number of the power-up needle? I asked the dealer and he just stared at me, so looks like I'll have to go elsewhere to get what I need. Also, the manual states that the stock pilot jet is #42. Would that meet the requirements for my altitude or should I still go with the #45? I plan to leave the bike stock except for removing the end cap and the snorkel.

What are your recommendations for my altitude and gentle to medium trail riding....no racing (I'm far too old now :cry: ).

Any help you could provide would be greatly appreciated.

Edit: Found the jetting corr chart - I come up with .96. From reading your info, I'll need a 115 main jet and can leave the #42 pilot. Now all I need is the needle number. Also, when I bought the main jets from someone on here, he did include a needle that has C30F engraved just under the grooves. Is that the power-up needle? (Sorry, I forgot that he had included a needle). Average summer temps here are 85-95F and I hear that the winter temps are in the low 50s to mid 60s....I've only been here a few months, so don't know for sure what the winter is like.

Cheers,

Mac

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MotoMac,

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.

Mike

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Thanks for the great info, I learn so much here, Its a great resource.

:cry: Where do I find the Jetting Chart that was mentioned in these posts?

Thanks,

Michael

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FWIW, I took my 230 out for a ride yesterday. It hasn't been run in a few weeks. I remembered that BBR wrote the jetting on the carb. It said 130 main and 45 pilot. My engine is mildly ported and port matched on both sides. It has a mid range WebCam special grind, BBR complete exhaust, CR-85 airbox, and the carb is the BBR carb kit for the 230. I have no idea what needle, just passing the jetting #s on. It rips, but might need a fatter main. Clint

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XT225,

>> Where do I find the Jetting Chart that was mentioned in these posts? <<

Just click on Search in the upper right hand corner of your screen and enter "Jetting correction". There will be several "hits" on that, but you'll find the one with the charts and explanation attached. Good info...

Cheers,

Mac

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Master Coeshow...

On Saturday I installed the 120 MJ, the C30F needle (but left in the original needle jet as you recommended), stayed with the 42 PJ, tried both 2 and 2.5 turns on the fuel mixture screw, and removed both the exhause insert and the snorkel. It starts easily and idles just fine. It also clears up fine after sitting upside down for a couple of minutes while I climbed back up the hill to where it was sitting -- but that's another story! :) ) It does seem to have more grunt down low and upthrough the mid rev range.

However, it still pops on deceleration (not as bad as before). It also starts to misfire a bit a wide open throttle. I don't think I'm hitting the rev limiter because it sounds like it's revving about the same as it did before I did the mods, but then again I don't have a calibrated ear. :) All the riding this weekend was between 3800 and 5100 ft (according to the GPS). Any suggestions?

By the way....thanks a bunch for the step-by-step instructions in the sticky. I only deviated from them by disconnecting the two throttle cables and pulling the carb off the bike completely. That makes it a heck of a lot easier to work on it!

Cheers,

Mac

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MotoMac,

It sounds as if you are very close on the jetting. At 5100 ft your jetting will be a tad richer than at 3800 and below. If you find or know that you will be riding at these elevations permanently, or mostly, you would likely benefit from a smaller main jet, and lowering the needle by raising the clip up into the third groove to lean it out some. You may even find that your bike runs best with the needle clip in the second clip position!!(unlikely, but possible) Every bike is a little different. Even though the factories install all of the same parts, no two bikes will be Exactly the same.

Jetting is always compromised somewhat when making extreme elevation changes. I know that a 120 main is certainly rich enough at sea level at wide open throttle. This would typically be the leanest condition / elevation.

I am not at all familiar with the terrain in Swaziland. Again, depending on your elevation and climate that you ride in the most, will dictate your ultimate choice in jet sizes and carb settings. A slightly rich mixture will not damage the engine except for a little performance.

Popping on deceleration is caused by a slight lean condition. It can be adjusted by turning the fuel mixture screw out some more. Do not exceed 3 full turns out from the fully seated (in) position.

If you jet for higher elevations and then return to much lower elevations with out the proper adjustments, the engine will again be jetted incorrectly, and performance will suffer.

The difference is that LEAN jetting can be detrimental to long engine life. A too lean condition can raise the engine temps critically high, and possibly do damage depending on the conditions.

Good luck !! Experimentation is key! I also remove the carb completely when diving in for changes. I find it much easier as well. After a few removals it becomes old hat right?

Mike

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I was the one that made the correction chart. If you ahve the main jets, myswell go for it. Takes a matter of minutes to change out the main and pilot. :)

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Mike,

>> At 5100 ft your jetting will be a tad richer than at 3800 and below. If you find or know that you will be riding at these elevations permanently, or mostly, you would likely benefit from a smaller main jet, and lowering the needle by raising the clip up into the third groove to lean it out some. <<

I will be riding at those altitudes almost exclusively. My house is at 4080 ft and the area where I ride is about 150 sq mi of large hills (or maybe small mountains) going up to around 5500 ft with the vally floor at 3800 ft. It's only 3km from my house to the riding area and we can legally ride unlicenses dirt bikes on the street when going to/from the riding area. I have a 115 MJ and will try that next. I'll leave the needle where it is now (4th groove from the top) until I see how it runs with the smaller MJ, and then go from there.

>> I am not at all familiar with the terrain in Swaziland. Again, depending on your elevation and climate that you ride in the most, will dictate your ultimate choice in jet sizes and carb settings. <<

Mostly mountainous along the western border (where I am) that gradually drops off to lowveld in the east with elevations around 1500 ft. Since the entire country is less than 100 miles wide, the lower elevations are not that far away. If we plan to head out that way, it only takes a few minutes to change out the MJ anyway, but those occasions will be rare.

>> Popping on deceleration is caused by a slight lean condition. It can be adjusted by turning the fuel mixture screw out some more. Do not exceed 3 full turns out from the fully seated (in) position. <<

So far, that's the hardest thing to do without burning the crap out of my hands!! I'm trying to figure out some sort of tool to make so that I can adjust the mixture screw away from the exhaust heat! Lots of cursing and the smell of burnt skin when I'm making those adjustments. :)

>> The difference is that LEAN jetting can be detrimental to long engine life. A too lean condition can raise the engine temps critically high, and possibly do damage depending on the conditions. <<

These engines seem to run quite hot normally, so I'm not sure how to tell if it's running extra-hot. Guess I'll know when it siezes, huh?

>> I also remove the carb completely when diving in for changes. I find it much easier as well. After a few removals it becomes old hat right? <<

Yep...much easier. I will say that modern dirt bike carbs are considerably different than the ones from the 70's!

Again....thanks for all your help.

Cheers,

Mac

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MotoMac,

Remember that the main jet will only alter the performance of your engine from 3/4 -full throttle riding. My guess is that you rarely ride at full throttle except for possibly a few seconds at a time. Most everyone rides their bike on the needle. I would recommend that you try lowering the needle as this change will be instantly felt, either better or worse. Untill you can get out into an open area where you can keep it "pinned" wide open, will you be able to sence if the main jet change has made an improvement.

I feel confident that if you do ride mainly in 3800-5000+ feet, a 115 will work fine. I didn't mean to imply doom if you do decide to go down in elevation. You could easily ride all the way down to the beach. You may not even be able to detect ay difference in the way your bike runs, and in fact because of the thicker air you may notice a slight increase in performance!

If your bike IS jetted too lean, the performance will suffer. You will be able to detect that "something's not quite right"

Here's a tip. As long as you continue to feel performance improvements with what ever jetting changes you make, you're going in the right direction. If the engine is too lean or too rich, performance falls off. Simple as that. Just make sure to make all of your comparisons with the engine at full operating temperature.

Mike

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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.

Mike

What make you change from 132 to 120 as the best main jet? It's a big gap. I have the 132 and I find my setting great, then again, I'm not a pro. :)

Cedric

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I had the same question as CrazyCedric, Why did the recommended change span such a large gap, from 132 to 120? I thought I was reading wrong at first. :)

I have purchased the new needle and a 120 main jet and 45 pilot and a BBR exhaust system. Hope it works at 1200 feet and 110 degrees. I think the biggest issue for us Arizonans is the wide spead in temperature say 30 to 110+ degrees. This seem to be as much a factor as altitude differences.

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I wont yell at ya guys cuz ur new.

I think it was coeshow that had dynoed the 230 and found it to be to rich at a 132. He found max performance /w/ a 120. I run a 122. yet i think it may be to lean. I'm not too sure yet. :)

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Cedric,

Like you and many others, I also installed a 132 main jet at the same time I installed the "power-up" needle. The bike ran noticably better, and I was happy. I have been developing big bore kits and engine performance parts for the 150 and 230. I was in the process of dyno testing a big-bore 150 (188cc) with a mild cam, and was using the A/F analyzer to fine tune the mixture and record the results.

Since I had never dyno'd a stock 230, I was able to make some comparison testing. We had a stock 230 available with the "power-up" mods, (including 132 main jet) and decided to gather some data. We discovered that the mixture was a little on the rich side for peak performance. We dropped the main down to a 125 and this showed improvement. We then dropped to a 120 main and made more improvement!

Dyno testing with A/F analyzer is how I came to know that a 120 main is closer to optimum size main jet for this application.

Mike

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Phill,

I wish the results were that good but no. The improvement in peak HP was low. Heres the data:

132 main = 17.19 HP @ 7800 RPM

125 main = 17.53 HP @ 7800 RPM

120 main = 17.83 HP @ 7800 RPM

Total of .64 HP. Not much, but still more !! This also allowed for a better over rev as well. Power would still fall off after 7800, but not quite as fast as with the 132.

I may exlpore this area again at a later date. I swapped in a 120 in my stocker now too. Runs great!!

Mike

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