Pilot Screw turns? - Kawasaki Vulcan 750 Forum : Kawasaki VN750 Forums
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post #1 of 12 (permalink) Old 07-30-2015, 10:19 PM Thread Starter
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Pilot Screw turns?

Going by the service manual carb rebuilding section it states:
"Turn in the Pilot Screw and count the number of turns until it seats. This is to set the screw to it's original position when re-assembling"

What I counted was rather surprising. The front carb was close to what I expected at 1-1/4 turns, however the rear carb turned in 2-3/4 turns before seating. Both carbs had what I thought to be the factory plugs in the Pilot Screw tunnel.

Has anyone ever encountered such a vast difference?

It seems to me the last time I replaced these Pilot Screws in a Vulcan I just turned them in till they seated and then backed them out 1-1/2 turns.

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TheDV8

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post #2 of 12 (permalink) Old 07-30-2015, 10:56 PM
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Quote:
Originally Posted by A6ULdv8 View Post
Going by the service manual carb rebuilding section it states:
"Turn in the Pilot Screw and count the number of turns until it seats. This is to set the screw to it's original position when re-assembling"

What I counted was rather surprising. The front carb was close to what I expected at 1-1/4 turns, however the rear carb turned in 2-3/4 turns before seating. Both carbs had what I thought to be the factory plugs in the Pilot Screw tunnel.

Has anyone ever encountered such a vast difference?

It seems to me the last time I replaced these Pilot Screws in a Vulcan I just turned them in till they seated and then backed them out 1-1/2 turns.

Regards,
Yes, when I did mine there was a difference of almost one full turn. 2 1/2 turns out seems to be a good starting point. Under 2 turns out is very lean.

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post #3 of 12 (permalink) Old 07-30-2015, 11:17 PM
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They set the rear richer because the rear jug runs hotter than the front.

There has been a few bikes that turned up with different jet sizes front to rear too...

Read your plugs and adjust accordingly...

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post #4 of 12 (permalink) Old 07-31-2015, 08:35 AM
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also, the front and rear needles are different

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post #5 of 12 (permalink) Old 07-31-2015, 11:57 AM Thread Starter
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Quote:
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also, the front and rear needles are different
Well that explains something else I wondered about. I ordered these kits which having the exact same parts I wondered why there is a different kit for the front and rear. Makes sense if the needles are different.


Thank you guys for the input. I feel reassured about the settings now.

Regards,

TheDV8

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post #6 of 12 (permalink) Old 08-01-2015, 06:44 PM
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Ok now I'm confused. I degoated, ear shaved and rejetted 42/142 for both carbs as I read in the ear shave process on here. Could this be causing my gas consuption issue and possibly my bogginess?
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post #7 of 12 (permalink) Old 08-01-2015, 07:28 PM
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Ok now I'm confused. I degoated, ear shaved and rejetted 42/142 for both carbs as I read in the ear shave process on here. Could this be causing my gas consuption issue and possibly my bogginess?
every bike is different. normally, if your exhaust is stock, or at least the stock muffs, you may NOT need to rejet. if you free up the exhaust with aftermarket or even straight pipes, you WILL need to rejet.

larger jets do increase fuel consumption, as does riding habits. I have stock jets on my earshave (I have stock exhaust), and get about 44 mpg (strickly city riding, LOTS of stop/starts and traffic), and I tip the scale at 280ish. the amount of throttle 'twisting' you do will greatly affect mileage

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post #8 of 12 (permalink) Old 08-01-2015, 07:48 PM
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Hmmm so it sounds like keeping the original mufflers may actually be causing my issues. Lot's of boggy sound spit n sputter in down shift no matter what I set the carbs at. I even set the floats. This piece is stumping me n I don't have the $$$ to buy a set new. Yet I've also read that anything other that bought sets there's a lot of math and calculations to get a hand made one right.

I'm just chasing my tail. Lol
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post #9 of 12 (permalink) Old 08-02-2015, 12:07 PM
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You could try a different set of mufflers...

Perhaps you should try going back to the stock jets?

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Last edited by Knifemaker; 08-02-2015 at 12:09 PM.
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post #10 of 12 (permalink) Old 08-02-2015, 05:55 PM
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Took off the mufflers n went straight pipe for now.
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