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So i've been puttering around in an effort to break in the engine and looks like i have some carb tuning to do. It rides really strong with quick on-throttle responsiveness and no bogging. Problem is plugs are fouled. This is where my ghetto A/F meter comes into play. It was reading around 10 at idle and it would actually go up (get leaner) on throttle and then go back down at higher revs. I think the going down part is good, i.e. 1/3 to full-ish throttle (it was reading around 10 near at about 3/4 throttle). I'm just not sure about the 0-1/4 throttle positions. My first order of business was leaning out the air screw. I opened this up and got the AFR up to 13.

Question for the peanut gallery, what would be a good target AFR at idle? Or do most folks tune by senses. I would think an AFR lower than 12 is too rich at idle (target 13-14?). The Mikuni pilot jet is a 30 (it came from Sudco with a 35). I'm wondering if i need to go down to a 25 (lower is leaner). I may also need to lower the needle a notch by raising the clip (it's on the mid notch and came from Sudco 2nd from the bottom), so raising the clip one would be a delta change of two positions in the leaner direction from where Sudco initially set it up. And/Or should i change the needle jet back to a P0. It's a P2. Lower is leaner and came from Sudco with a P0.

I mention Sudco because i bought the set from them specifically for a Commando, but that doesn't mean their settings are the best.

<blockquote data-quote="TomU" data-source="post: 623398" data-attributes="member: 7984">So i&#039;ve been puttering around in an effort to break in the engine and looks like i have some carb tuning to do.&nbsp; It rides really strong with quick on-throttle responsiveness and no bogging.&nbsp; Problem is plugs are fouled.&nbsp; This is where my ghetto A/F meter comes into play.&nbsp; It was reading around 10 at idle and it would actually go up (get leaner) on throttle and then go back down at higher revs.&nbsp; I think the going down part is good, i.e. 1/3 to full-ish throttle (it was reading around 10 near at about 3/4 throttle).&nbsp; I&#039;m just not sure about the 0-1/4 throttle positions.&nbsp; My first order of business was leaning out the air screw.&nbsp; I opened this up and got the AFR up to 13.&nbsp; Question for the peanut gallery, what would be a good target AFR at idle?&nbsp; Or do most folks tune by senses.&nbsp; I would think an AFR lower than 12 is too rich at idle (target 13-14?).&nbsp; The Mikuni pilot jet is a 30 (it came from Sudco with a 35).&nbsp; I&#039;m wondering if i need to go down to a 25 (lower is leaner).&nbsp; I may also need to lower the needle a notch by raising the clip (it&#039;s on the mid notch and came from Sudco 2nd from the bottom), so raising the clip one would be a delta change of two positions in the leaner direction from where Sudco initially set it up.&nbsp; And/Or should i change the needle jet back to a P0.&nbsp; It&#039;s a P2.&nbsp; Lower is leaner and came from Sudco with a P0.I mention Sudco because i bought the set from them specifically for a Commando, but that doesn&#039;t mean their settings are the best.</blockquote>

[QUOTE="TomU, post: 623398, member: 7984"] So i've been puttering around in an effort to break in the engine and looks like i have some carb tuning to do. It rides really strong with quick on-throttle responsiveness and no bogging. Problem is plugs are fouled. This is where my ghetto A/F meter comes into play. It was reading around 10 at idle and it would actually go up (get leaner) on throttle and then go back down at higher revs. I think the going down part is good, i.e. 1/3 to full-ish throttle (it was reading around 10 near at about 3/4 throttle). I'm just not sure about the 0-1/4 throttle positions. My first order of business was leaning out the air screw. I opened this up and got the AFR up to 13. Question for the peanut gallery, what would be a good target AFR at idle? Or do most folks tune by senses. I would think an AFR lower than 12 is too rich at idle (target 13-14?). The Mikuni pilot jet is a 30 (it came from Sudco with a 35). I'm wondering if i need to go down to a 25 (lower is leaner). I may also need to lower the needle a notch by raising the clip (it's on the mid notch and came from Sudco 2nd from the bottom), so raising the clip one would be a delta change of two positions in the leaner direction from where Sudco initially set it up. And/Or should i change the needle jet back to a P0. It's a P2. Lower is leaner and came from Sudco with a P0. I mention Sudco because i bought the set from them specifically for a Commando, but that doesn't mean their settings are the best. [/QUOTE]