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Discussion Starter · #1 ·
Im starting a new thread based on jetting. The info i get could also help people in the future.
07 new wiseco 11.1 piston. Stock exhaust with baffle removed.uni filter with hole cut out of air box lid.93 octane. Stock jetting. I got DPR9Z plugs. Warmed motor up then went to 5th gear then wot for about 10 seconds then shut it off. Plug tip was white.
Im at about 95ft above sea level.what jetting is recommended?
 

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Discussion Starter · #2 ·
I want to thank "Here 2 help" for all your help and info on my other thread...
Im going to post 2 pics. The first will be stock jetting without air lid.
2nd will be 165 main change only and air box lid covered.
Should i try running a 170?
 

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Second pic looks closer to perfect - sure, try a 170 or a 180 - try different sizes until is performs as you desire it to or get it on a dyno with an O2 sensor installed in the exhaust and then adjust he jetting based on the dyno and O2 readings.
 

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Discussion Starter · #4 ·
Is it safe to run it on the rich side or should it be close to perfect?
And on the fuel screw if its closer to being turned in all the way i put a smaller pilot in and if its more then 4 turns out i put a bigger pilot in?
 

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Rich is always safer than lean, but lean will produce the most power. Ideally you want to be as lean as possible without overheating (scorching) the piston. 14 to 16 parts of air with one part of fuel is the sweet range - the engine will run as rich as 5 to 1, but it's like running with the choke on constantly and it will run as lean as 100 to 1, but you need computer control to enrich it up for starting and can only achieve a constant ratio with no wind, no changes in altitude, a constant humidity. air density and no changes in speed or engine load.
 

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Discussion Starter · #6 ·
Ok ill try a 170 and check....once i get the plug tip close to perfect with the 5th gear wot pull, When just riding normal for a few days will the plug tip turn blackish or will it stay brownish?
 

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That will depend on the air:fuel ratio in the mid-range where most 'norma' riding occurs - the main jet is the only fuel control at WOT and while 'normal' riding includes periods of WOT, more time is spent in the mid-range. If it is black after riding 'normal', drop the needle in the slide a notch and if dropping the needle causes an undesireable condition, put it back and enjoy the ride.
 

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Discussion Starter · #9 ·
How do i go about adjusting the fuel screw properly.i got it set to 3.5 turns out
 

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How do i go about adjusting the fuel screw properly.i got it set to 3.5 turns out
Ride the vehicle for about 15 to 20 minutes to get the engine up to normal operating temp - connect an accurate tachometer.........

Here's the procedure as copied from the service manual:
4740
 

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Discussion Starter · #11 ·
Ok here is a 172 main jet. I have a 175 and 178 left to go higher... Should i try the 175 or 178 or does the plug look good?
On the fuel screw adjustment its gonna take me alittle longer cause im doing the rpm by ear as i dont have a tach yet.
 

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Ok here is a 172 main jet. I have a 175 and 178 left to go higher... Should i try the 175 or 178 or does the plug look good?
Plug looks rich already, so I would not go any bigger on the main jet, but you can just to get a feel for the change.

Pilot screw is for idle only and all you want is a smooth idle for a minute or so - it should not be left to idle more than a minute when hot and about 5 minutes when cold
 

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Discussion Starter · #14 ·
Also my idle is smooth now and still at the 3.5 turns out...but i will adjust to spec
 

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Should i drop the 170 main in or stay with the 172?
Stay with the 172 for now - if you start experiencing plug fouling during or after WOT use, then drop to the 170 - if no plug fouling, check the plug at the end of an average day of riding
 
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