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686 Jetting.......Oh what fun

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Old Aug 23, 2002 | 12:54 AM
  #1  
GregV's Avatar
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I have been tinkering with my set-up again:

Before:
187.5 Right (3-1/4 turns) / 182.5 Left (3 turns)
25.0 Pilots & needles in the 5th position.
Elevation: 875
No air box lid / K&N filter w/ outerwear
Yoshimura Comp S.S. Full Pipe
Trinity Low Compression 686 kit

--------

Now:
187.5 Right (2-3/4 turns) / 185.0 Left (2-1/2 turns)
22.5 (stock) Pilots & needles in the 4th position.
Elevation: 875
No air box lid / K&N filter w/ outerwear
Yoshimura Comp S.S. Full Pipe
Trinity Low Compression 686 kit

Result, it seems snappier I haven't really got to run it much since the change, but thhe reason that I am boring you with all of the is that I have the imfamous red head pipes again. My plug was pretty black before when I checked it after idling so I decided to drop back down to the 22.5's. I was having a little bit is a hesitation at lower RPM's when I would be setting up for a jump. But when you pour the coals to her, she's as smooth as silk. I have a 190 & 195 main jets coming, but I thought I would try what I had first.

I'm going to take the air fuel screws out another 1/4 or 1/2 turn before I swap the jetting. That should take care of me for now, but I can see me tearing it down again and putting the 190 / 195's in to get a little more out of it. [img]i/expressions/face-icon-small-happy.gif[/img]

I see a lot of Trinity set ups out here running the stock pilots, so I thought I would give it a try.

Any thoughts? What size pilots are you other 686 guy's running??
 
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Old Aug 23, 2002 | 04:01 AM
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THEMOOSE's Avatar
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I'm guessing that red headers at idle isn't a big worry.
IMO it may be rich at idle & unburned fuel is igniting in the header at idle causeing the glow, Or it could be that the lack of air flow at idle is heating it uo enough to glow, or maybe your too lean at idle.

A lot of help I am huh!! LOL

*sigh* the one thing I miss about my 250R are the 5 min jet changes!!!


<< But when you pour the coals to her, she's as smooth as silk. >>


Personaly if it runs good at the mid &amp; top end I'd quit screwing with it &amp; just not let it sit &amp; idle for long periods.
 
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Old Aug 23, 2002 | 06:01 PM
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What size pilots are you other 686 guy's running?
 
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