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post #1 of 10 (permalink) Old 07-05-2015, 01:24 PM Thread Starter
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Smile Gas Tank & Jet Question. Sticky?

HAPPY 4th weekend all!


So I have a few questions. I've ear shaved and put 42/142 in each. Now going 40+ MPH I get great gas mileage yet 40- it seems to vanish. Would that mean I'd need to lower the 42 to say a 40 on the slow jet?

Second question is... My gas tank seems to have issues releasing its pressure. When it has pressure it hisses n makes air leakage sounds.

Other than the minor tweets I'm very happy I followed all your information. Now if this would allow me to upload a photo.

Any info would be great.
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post #2 of 10 (permalink) Old 07-05-2015, 02:00 PM
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What exhaust?

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post #3 of 10 (permalink) Old 07-05-2015, 02:12 PM Thread Starter
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I have degoated this bike w original headers and mufflers with straight pipe where the goat tied in. Damn thing runs nice yet it's a tweek here n there time.
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post #4 of 10 (permalink) Old 07-05-2015, 07:41 PM
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Should have close to the same back pressure. Might be fine with original jets
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post #5 of 10 (permalink) Old 07-06-2015, 08:22 AM Thread Starter
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Well I've installed 42/142 and was wondering if anyone that's done the ear shave and went the 42/142 jets found any issues with gas consumption on the lower end 's upper? My upper seems to be great with the142 jet yet my lower seems to be extremely thirsty and wasn't sure if I should back down the lower with a 40? I'm hoping someone has had experience with this issue as well has some insight for this ol newbie.
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post #6 of 10 (permalink) Old 07-06-2015, 08:59 AM
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gas milage is very relative to how its ridden.. lots of throttle twisting will reduce the milage a LOT. also, your physical size makes a huge difference as well.

for example.. my bike is shaved, stock exhaust, stock jets. I dont do a lot of throttle twisting (I do get in it now and then). I get about 42 mpg.. I am 5'10" and 280 lbs. thats a lotta mass to get moving from a stop, and a friggin sail when over 55 mph.

as far as the hissing, check out the POOGS threads for cleaning the vent system.. also, make sure the tank tube at back of tank is clear

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post #7 of 10 (permalink) Old 07-06-2015, 09:17 AM Thread Starter
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5'4" maybe 120lbs. Not much on throttle twisting myself. Once in a while I'll get up n it.

I'll check out the poohe thread. Thank you.
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post #8 of 10 (permalink) Old 07-06-2015, 10:13 AM Thread Starter
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Well gas cap seals will need replacing yet all flows well. I think the center seal was covering the hole since it seemed damaged. Now the gas usage issue. Hmmmm. Lol
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post #9 of 10 (permalink) Old 07-06-2015, 10:47 AM
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I'm earshaved, degoated, with screaming eagle mufflers right off the pipes and get about 40-45,depending on my throttle hand.bout 6' 180#s

ONE RATS ASS GIVEN PER POST
Support your local FREEBIRDS MC
1986/5 Vn700/750 Frankenfook cross eyed bitch "Mellisa Fayhe"
I am a BIKER and i'm proud.FREEBIRDS MC CENTRAL NY

lowered with progessive 412 10" shocks
rejetted for K/N Pods part#rc 2340
sportster seat

'I didn't lose my mind.i gave it away

BRING BACK WOLFIE."Peace and Carrots"RIP
"And I'm free...as a bird"John Lennon Free as a Bird
"I only carry when I have my pants on"Joe Robinson RIP aka Old Dog
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post #10 of 10 (permalink) Old 07-06-2015, 12:07 PM
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Remember that Jets are throttle related, not rpm or speed related.

You should take note of the throttle conditions. For example:

My bike is 140/42 with 2 shims. At the lower rpm range, and from 0-20% throttle, my bike hesitates. After that, it picks up like normal.

I think I need to down a jet size on the slow.
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