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2006 Cr125 Rant

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I bought an 06 cr125 leftover about 2 monhts ago. I rode it for about ten hours in all bu spent 20 bucks in spark plugs each time. The dealer kept on saying the problem would go away but it never did so i decided to jet the bike. I have tried mains starting with the stock 430 and am at the 410 right now. The pilot was a 55 but i dropped to a 50. Its on the second clip positions. Even though those settings should be lean for my average summer temps it still fouls plugs in 40 degree weather. The airscrew is 1 an 1/2 turns out. The bike feels very crisp it just still fowls plugs when you ride it. Need help please. The jetting forum provided absolutly 0 answers.

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Put in a new plug and warm the bike up. Wind it up in first, slow down and roll through a corner and roll on the gas out of the corner, still in 1st. What does the bike do, respond well? Act boggy? Sputter/choppy? My guess is the later. With the bike running, turn the AS out one full turn and ride the bike the same way again. Is it more repsonsive rolling out of the corner? If it is, I'm going to say it isn't by much. I think you need to drop to a 45 if not a 42.5 pilot. I think these bikes are way rich and the manual is way rich on the suggested pilot settings. I also think you are OK with your current needle clip location unless you sputter or are noticaing a bog past 1/4 throttle. Your bike isn't fouling the plug on the main, so don't worry about that for now.

Right now I am down to a 45 and need to go leaner on the pilot. I have a feeling I will be at 40 or even 37.5 by the time I am done. It was 15 degrees this past Saturday and I had to actually richen the main up to a 420 as the 410 I had installed left a noticable bog at 1/2 throttle. With the 45 pilot installed, adn the AS out to 3 turns as it liked for 45 degree weather the week before, the bike would bog in the scenario I told you to go through. I turned the AS in 1 1/4 turn and the bike pulled out of the corner while rolling on the throttle. That was great for that day, but when it warms up to the weather I like to ride in, it'll be fat again:)

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Aightn thanks i ordered a 45 40 and 37.5 pilot to try out and we will see how it works. What oil and ratio do you run?

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Here is where I am at as of yesterday

410 main (but I may go up to 420 in the milder temps)

37.5 pilot

stock needle clip position #2

AS 3 turns out

I had one ride on the plug that was in the bike, went out yesterday and fouled the plug after about 20 minutes. Turned the AS out to 2 1/2 (was at 1 1 3/4), put in a new plug and road for about 40 minutes and fouled the plug again. Turned the AS out to 3 turns, installed new plug, rode the rest of the day, checked the plug, looked good. As the day progressed the temp rose to around the mid 50's.

I'm thinking I will drop the needle to the first clip position and turn the AS back in a bit. Whenever it fouls it is right there in the transition between the pilot and needle. It ran good on the top end, but I think it could be better and just don't want it too lean on the top, that is why I am thinki9ng of going back to the 420 main while the temps are below 80 or so.

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If the air screw had to go out to 3 turns before it improved, you're still way too fat on the pilot. Get the pilot right first befoer moving the needle around. That alone may clear it up.

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Well i finnaly got it right. 410 main 2nd clip position with a 37.5 pilot. Yes i dropped from a 55 to a 37.5 even though its in the 50s outside.

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What does your plug look like? Should be a cocoa brown. I cant believe you dropped from a 55 to a 37.5 in that kind of weather. That is crazy! With the bike at it's normal runnning temp, put it on your stand and keep it idling, not to fast but not to slow either. Now turn your air screw to 1.50 turns out, wait about 30 seconds. If you have to twist the throttle to keep it running do so. Now slowly turn the air screw out 1/4 turn at a time. When you hear the bike idle at it's fastest, that's where you need to be. If your 3 turns out on the air screw, you need to richen your pilot. If your between fully closed and 1.50 turns out, you need to lean the pilot. Turn your idle back down, your ready to go. I would keep the needle at stock position. Hope this helps in the future. A correctly jetted carb is the best thing you can do to your bike, now enjoy that little rocket.

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What does your plug look like? Should be a cocoa brown. I cant believe you dropped from a 55 to a 37.5 in that kind of weather. That is crazy! With the bike at it's normal runnning temp, put it on your stand and keep it idling, not to fast but not to slow either. Now turn your air screw to 1.50 turns out, wait about 30 seconds. If you have to twist the throttle to keep it running do so. Now slowly turn the air screw out 1/4 turn at a time. When you hear the bike idle at it's fastest, that's where you need to be. If your 3 turns out on the air screw, you need to richen your pilot. If your between fully closed and 1.50 turns out, you need to lean the pilot. Turn your idle back down, your ready to go. I would keep the needle at stock position. Hope this helps in the future. A correctly jetted carb is the best thing you can do to your bike, now enjoy that little rocket.

Believe it. I am at a 35 pilot and I am 2 to 2 1/4 turns out on the AS. With the 37.5 I was pushing past 3 turns. I also went with a leaner needle and a leaner clip setting. Dropped on on the main as well.

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Jeez. Yeah Hondas jetting charts are absolutly terrible. Right now my bike is running perfect and the plug after i took it out is a perfect cocoa brown. It took a lot of time and effort to get it where it is now but it paid off. I was riding pretty tight trails off and on the throttle and checked the plug after and it was perfect.

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If your 3 turns out on the air screw, you need to richen your pilot. If your between fully closed and 1.50 turns out, you need to lean the pilot. Turn your idle back down, your ready to go. I would keep the needle at stock position. Hope this helps in the future. A correctly jetted carb is the best thing you can do to your bike, now enjoy that little rocket.

I think you wrote it backwards, for a two stroke that is.Over 2 turns out = you need to lean your pilot. Under 1 turn out = you need to richen.

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