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post #1 of 6 (permalink) Old 03-13-2010, 08:30 PM Thread Starter
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Need Some Jet Advice

I did a single filter ear shave a while back and used a double outlet K & N filter right under the tank. This baby is getting a lot of air now. I rejetted to 40 pilots and 140 mains with 2 shims under the needle valve. I noticed that it took a good roll of the throttle to increase speed and I was still getting a little surge at 70 MPH in a good wind like the bike was still running a little to lean.

I was going to see if I could go to smaller jets and bought 135's to try, but before doing that I decided to try another shim under the needle valve. That made a good difference. I don't have to roll the throttle as much and the surge is much less noticable though it's still there a little bit. I bet if I put a 4th shim it would be good but that's pulling the needle way up there.

To my thinking, it sounds like 140 is pretty close to where I should be. When I add a shim under the needle, I'm increasing the fuel getting to the air flow aren't I? If that logic is sound, then I don't think I'm going to be able to reduce the jet size. My question is does it make sense at this point to go with 142 main jets and remove a couple of shims from the needles?
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post #2 of 6 (permalink) Old 03-13-2010, 10:06 PM
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Going from 140 to 142 will not make much difference, the main does not fully kick in until around 70% throttle. If you are lean with the current jets I would go to #42 pilot and #145 main and 2 shims.

What exhaust do you have and where are your pilot screws set?

I would check the filter to carb and carb to head boots for leaks. The slightest vacuum leak will cause a lean condition and will drive you up a wall.


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post #3 of 6 (permalink) Old 03-14-2010, 12:53 AM Thread Starter
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For exhaust, I have Dynaglide mufflers with the baffels drilled out. Pilot screws are out about 2 turns right now.

I'll check for leaks around the boots and carbs tomorrow.
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post #4 of 6 (permalink) Old 03-14-2010, 05:13 AM
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Quote:
Originally Posted by AceMcgyver View Post
For exhaust, I have Dynaglide mufflers with the baffels drilled out. Pilot screws are out about 2 turns right now.

I'll check for leaks around the boots and carbs tomorrow.
Turn pilot screws out to 3 turns, then up to 5 turns if needed at half turn increments and Go back to 2 shims. Since you drilled out the baffles you will probably will have to go to #42 pilot and #145 main.


85 VN700 "Old Yella"

REBUILT ENGINE
CUSTOM PAINT
VANCE & HINES CRUZERS
EAR SHAVED AND RE-JETTED W/K&N'S
DUNLOP ELITE K591 FRONT & REAR
VOLTMETER
SYNTHETIC BRAKE FLUID
SYNTHETIC OIL & GEAR LUBE
PLEXISTAR 2 WINDSHIELD
SPLINES LUBED
ACCT'S GREASED W/TOC SPRINGS
COASTERD
LEATHER SADDLE BAGS
LEATHER TOOL AND ROLL BAG
PICKUP COILS GAPPED AT .018"
NGK CAP, WIRES, IRIDUMS
BARNETT FRICTION PLATES & SPRINGS
CUSTOM GRIPS, MIRRORS, LEVERS
ORIGINAL STATOR & R/R 14.5v
DEKA MF AGM ETX15L

Best Auto/Moto Insurance | Motorcycle Protection Today | FREE Trade-In Quote
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post #5 of 6 (permalink) Old 03-14-2010, 10:51 AM
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I'm at 140 with sportster XL mufflers and K&N style pods. I need to go up to 142 or 145 to make my vn happy.

DT

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post #6 of 6 (permalink) Old 03-15-2010, 10:00 AM
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ACE: I had found an answer to all jetting.Much easier and much faster. Check it out.
http://www.ask.com/bar?q=thunder+pro...=1257611133208 This is a simple way to change settings .Thanks for checking out this product.
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