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Discussion Starter #1 (Edited)
im putting road burners on my 650, with just a K&N air filter and no other mods, can i get away with just opening pilot mix screws, if anyone has this set up what jetting adjustments did you do, i thinking of going from #90 oem main jet to a #105 and opening the pilot screws to 3.25 turns, any know if this set up should work or should i go richer or leaner, this seems to be a common upgrade on 650s so there should be some good answers , i really don't want decel popping
 

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Most I see don't worry about changing mains. I've never seen anyone take a 650 to the dyno to confirm the actual AFR throughout the trottle range, but the bikes seem to run OK or we'd hear a ton of bitching about poor performance.

I like to do a "lean drop" on the PMS instead of just guessing or going by what someone else has done to make sure I'm set correctly for my particular environment.

I'm sure how ever you set it up...it'll work. These are very forgiving carbs.
 

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Discussion Starter #3 (Edited)
Most I see don't worry about changing mains. I've never seen anyone take a 650 to the dyno to confirm the actual AFR throughout the trottle range, but the bikes seem to run OK or we'd hear a ton of bitching about poor performance.

I like to do a "lean drop" on the PMS instead of just guessing or going by what someone else has done to make sure I'm set correctly for my particular environment.

I'm sure how ever you set it up...it'll work. These are very forgiving carbs.
does yours pop on decel. i know when you richen a mixture to get the popping out the engine usually is not in perfect tune most times the carbs are slightly rich at idle to get the popping out but most guys will sacrifice a bit of performance to not to have popping on decel, from what iv heard a perfectly tuned engine will pop on decel there's no getting around it unless you detune a bit. i'm at sea level so the bike is already running lean to begin with, i'll keep opening the screws a little at a time and see what happens, it doesn't pop much now with debaffled stockers
 

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I always wondered why they would say it's too rich when you're getting a backfre on decel. Backfire on decel means you're a bit too lean at idle..... I guess it's all in what you want to accomplish. I'm not racing my bike and 100ths of a second don't really matter much on a 600 lb bike with only 70 HP anyway....so I just tune it where I like it to be. Leaner always means faster.....but I guess I'm just not in that big of hurry any more.:smile:
 
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