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Discussion Starter · #1 ·
I have my CB160 running pretty good and have gone a few long rides. I pulled the plugs after the last ride to check compression after a re-ring (128psi left cylinder and 130psi right cylinder) and was looking for some advice on color. It has been along time since I have had to refer to plug color for rich/lean indication. Are these looking about right or is some adjustment needed?

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Your plugs look good to me as well. Keep riding and enjoy.
 

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Discussion Starter · #4 ·
Thanks for the advice! Rode to work today (50 miles @ 45 - 50 mph) and I noticed the header in the side with the lighter colored plug (plug on the left in the above pic, header pipe on the right in the pic below) was a little more discolored then the other.

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This is my first twin so I am still getting to know the sights and sounds of a properly tuned bike and want to make sure things are as they should be (or as close as I can get them).
 

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Are you using the cleaned original jetting or replacements from a kit?........
Your plugs suggest that you are a "smidge" rich at idle (which is actually good) but leaning out somewhat at wider throttle openings.....
Your pipes suggest that it becomes too lean.......
I'd drop the clips on the metering (slide) needles (raising the needles a bit) and see if running at higher speeds/ wider throttle openings improves (IF ORIGINAL JETTING).....
IF "kit" jets, clean the originals and re-install them.......
 

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Discussion Starter · #6 ·
I am using the original jetting. I will drop the clip one notch for the ride home. I did notice a very slight hesitation when rolling back in to the throttle after a curve where I had to back off the throttle a bit but not down shift. It didn't seen to matter if was turning left or right. It was very slight and didn't really effect getting back up to speed.
 

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I'd drop it two notches...... Fouled plugs are MUCH cheaper than holed pistons (although I don't think you are currently quite that hot).... Ridden hard, the "straw" color is not that unusual, but the blue/purple color is too hot, especially for a double walled header pipe....
 

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I read somewhere that modern fuels dont display the same plug colouring as the old leaded stuff. Even so, I still aim for that perfect tan colour on main jet. Dunno if its mine, but pilot settings for tickover, slow running always seem to be slightly rich for best performance, no hesitations.
 

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Discussion Starter · #9 · (Edited)
I lowered the clips by two notches and it wanted to bog and not idle no matter how I adjusted the idle air. I moved the clip up one notch and it smoothed out. The hesitation is much better (hardly noticeable). Plugs are more equal and the exhaust only turned slightly straw color.

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