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Discussion Starter · #1 ·
The plug on the left is what I started out with, and after tuning 'by-the-book' turning in to higher RPM etc until it stabilized at 1100 rpm, the one on the right is what I have after 120 or so miles...does it look too lean? I think I am happy with it as it looks 'just-right'...maybe it needs a bit more brown?



 

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The one on the right looks good to me
Maybe just a touch to lean but looks good


Hopefully Larry the carb guru can chime in on this one


Cheers........Keith..............
.........
 

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Discussion Starter · #5 ·
The beauty is they are both 'I'dentical.



A lot of folks to thank for the end result. I lost track of how many posts it took to get there. One of the most important tools to achieve this was using a digital 'Tiny Tach' that is accurate to +/- 10 rpm...this was most helpful to watch when I was closing the mixture screws to watch the RPM go up.



Special thanks to Rickbert's chart, Shep's Tuning procedure, Larry's Carb book, Marshall, Stitch, Reg, and anyone else that helped with sync'ing the carbs and my homemade manometer...on the list goes.



Isnt this forum GREAT?!?
 

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hmmmm dunno

looks a wee bit on the lean side to me

as it has a slight glazed look.

Not a carb expert and may well be wrong but

I like to see a bit of a tan
 

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hmmmm dunno

looks a wee bit on the lean side to me

as it has a slight glazed look.

Not a carb expert and may well be wrong but

I like to see a bit of a tan
i agree with Reg.you are running lean.look for a little suntan.....tweak again.

a lean condition might burn a valve
 

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Discussion Starter · #8 ·
I thought it might be a bit lean...it is so close that is why I thought I would post a pic. Any thoughts on how much I need to turn em out to get her ideal? I am thinking of starting at a blade width on each side if lean is the case.
 

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You created the change in color between the plugs by just turning the idle mixture screw? No jet change?
 

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Was the bike ridden immediately before the plugs were removed or allowed to idle for an extended period?



The 'after' plug looks lean to me too.



EDIT: I'd go a quarter turn out and recheck.
 

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I agree, looks quite close, but a bit lean for my taste, might be ok, but I'd rather go slightly rich to keep things safe. It does look a hundred times better than it did before though, you're getting really close!!!
 

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Discussion Starter · #12 ·
You created the change in color between the plugs by just turning the idle mixture screw? No jet change?


Correct...no jet change. Just followed a tuning procedure posted by Shep, where the mixture screws are turned in until the RPM goes up, adjust the idle repeat other side repeat etc. These plugs were pulled after a 100 or so miles, no extended idling,...pulled into the garage, shut her down. I think I checked them a couple days after the first real long ride.



I did open/turn out, the mixture screws last night by about a blade width of the screwdriver...
 

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Correct...no jet change. Just followed a tuning procedure posted by Shep, where the mixture screws are turned in until the RPM goes up, adjust the idle repeat other side repeat etc. These plugs were pulled after a 100 or so miles, no extended idling,...pulled into the garage, shut her down. I think I checked them a couple days after the first real long ride.



I did open/turn out, the mixture screws last night by about a blade width of the screwdriver...
dont get upset if the amount you turned out shows no difference.....but,youl get there
 

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Discussion Starter · #14 ·
dont get upset if the amount you turned out shows no difference.....but,youl get there
thanks for the encouragement Bandit. I figure a blade width at a time and eventually I will get there--I want to avoid overshooting at this point. Blue skies abound for the moment which might bring about my first Bike Night with the CX tonight at Quaker Steak! ...of course with the temps, I'll have to be back in the barn before sundown.
 

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Rick,



Where abouts are you? I ride from Mansfield to Middleburg Heights and back every day.



TT
 

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I'd still go another quarter turn out and then start adjusting back in by small increments. I would think your bikes 'happy zone' will lie within this quarter turn somewhere and your motor [in the short term] is better off slightly too rich than too lean.
 

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The plug on the left is what I started out with, and after tuning 'by-the-book' turning in to higher RPM etc until it stabilized at 1100 rpm, the one on the right is what I have after 120 or so miles...does it look too lean? I think I am happy with it as it looks 'just-right'...maybe it needs a bit more brown?



About how many miles on the right hand plug?
 

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never heard the trick adjust until the rpm goes up, I cleaned my carbs this winter, turned the screws out I believe 2 1/2, with open exhaust, and noticed the plugs were showing lean, turned out another 1/4, still a touch lean, another 1/4, looking better finally, might adjust them the way shep called for and see how close it is to where they are now...
 

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One of the problems I have found with all my CX carbs,even well serviced,is that the idle mixture screws are not as linear as I would expect and also can vary from side to side so the 2.5 times out is only a starting point.



I put this down to age variations.Sometimes it's a full turn on one set to get the desired amount of mixture change.I've verified this with my,"Gunson Colourtune" device.It's quite easy to get them perfect with this device you just keep going until you get a perfect,"Gunson Blue" coloured spark/ignition mixture.It also depends on how well serviced the low speed idle circuit in the carbs is and NO air-leaks in the carb boots on either side of the carbs.
 
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