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Jetting help

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I recently picked up an '07 CRF230f and removed the snorkel and baffle. I also replaced the air filter with a Uni-filter. When I replaced the pilot jet with a #45 the fuel screw was 3 turns out, so I tried a #48 pilot and the fuel screw is now 1 turn out. Now for my dilemma. The power up needle is raised all the way (clip in the bottom position - 5th) and the main jet is a #135 and I am running lean. Doing a plug check from a 1/2 throttle run as well as a full throttle run gives me a white plug. I know I can go bigger on the main if I need to but what are my options when the power up needle is in the richest position and it's still lean (I don't want to restrict air flow to compensate).

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thats big jets to be running lean,I'm running a 48P and a 120M clip in 4th position.My plug shows running rich,was thinking of dropping to a 45P.You should check for air leaks around the carb or intake,seems to me you should be running on the rich side if anything.

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Thanks etuke. I have the same opinion you do. I have checked for air leaks and didn't find any. I guess I could always put the snorkel back in or something, it's just I don't want to.

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Keep in mind, the size of the optimum main jet is affected by the type of needle. I believe the Power-up needle has a different shape than the OEM needle? I think that's why the Power-up kit comes with such large main jets? But, I also agree you should check for an air leak if you are still lean.:banana:

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Doing a plug check from a 1/2 throttle run as well as a full throttle run gives me a white plug.
You can't reliably do a plug check with modern fuel. You have three choices:

1. Use an AFR probe to read the air/fuel ratio.

2. Seat of the pants - ride and see how the engine responds. Adjust as needed.

3. Ride 5 miles or so and then check the plug.

I do #2 first, then when I think it's ok, I do #3.

Keep notes and try to make sense of how the engine responds as you make changes.

Confirm this approach with Eddie the jetting expert in the "Intake - Jetting / Fuel Injection" forum.

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The bike runs great. I always have that fear of running lean because of the damage it can cause. I will hop over to the Jetting Forum and see what I can find over there - thanks.

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