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Discussion Starter · #1 ·
HELLO I HAVE RECENTLY PURCHASED A MOTOR AND WONDERING IF I NEED DIFFERENT JETTING THAN THE FACTORY JETS??
HERE IS THE INFO ON MY MOTOR

2001 Yamaha Raptor 660 YFM660RN Motor. This excellent strong running motor has a Cylinder works 102mm 686 Big Bore kit with JE race gas piston, ported head with Kibblewhite valves, dual valve springs, billet retainers, and a Hot cam in it.

THANKS FOR YOUR HELP
 

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Master of the Electron
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Will you be running this with stock exhaust and air filter/airbox? If not (and I can't see why you would), more detail is needed.
 

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I am unique
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Right now i have an hmf exhaust and not sure what i should do about my airbox?? Suggestions??
Using a complete stock airbox with unmodified snorkel, you can use the stock jetting, using a modified air box you will need aftermarket needles and larger main jets, depending on how much you mod the air box...................;)
 

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Master of the Electron
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Yes you do.
 

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Git-R-Done
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Vito's makes a nice jet kit for 50 bucks, it has everything you need.
 

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With a stage 3 Hotcam you might need to mix a little bit of race fuel in it but you might get by with 93. If you have a stage 2 cam then you will more then likely need race fuel to mix with it.

Additive is not gonna help you. Buy some 93 and some race fuel and just mix some in. You can do a compression calculator on the net somewhere and see what psi your getting in your cylinder and go from that. I think 93 is good up to 225psi.
 

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I am unique
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With a stage 3 Hotcam you might need to mix a little bit of race fuel in it but you might get by with 93. If you have a stage 2 cam then you will more then likely need race fuel to mix with it.

Additive is not gonna help you. Buy some 93 and some race fuel and just mix some in. You can do a compression calculator on the net somewhere and see what psi your getting in your cylinder and go from that. I think 93 is good up to 225psi.
+1..............:D
 

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Master of the Electron
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Just because you are told you must run a minumum octane doesn't mean this is based upon any reality - most people do not truly understand octane, it's actual purpose and how to determine how much is necessary. Instead they tell you what they've been told based upon anecdote and wive's tale.

The advice you get in this forum (at least from the veterans) should be heeded.
 

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Discussion Starter · #19 ·
ok i have the motor installed and now the bike is running great at an idle but cuts out when you mash the throttle very much at all. If you press it slow does okay if you floor it cuts out pretty good. i have the air box is stock the motor listed above and a hmf slip on. I have the 140 and 145 jets with 25 pilots. Is this right??
 
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