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Main Area => General GS500 Discussion => Topic started by: chrishiggs on October 01, 2009, 01:46:28 PM

Title: Raising needles- possible with carbs in situ?
Post by: chrishiggs on October 01, 2009, 01:46:28 PM
Hi Folks

Sorry if this is posted elsewhere but can't find any posts...

Just wondering if there's a how-to or similar on raising the jet needles without removing carbs or whether the carbs need to come out first? Got a '99 UK spec GS with a free-flowing pipe from a CRF Honda, standard air filter and still have the horrible flatspot around 5-6k. Upjetted to 125 mains and the plugs look good and healthy when I do plug chop. It seems the next thing to do is raise the needles. As standard they are set at the third groove from the top. Anyone got any suggestions where to go from here and how best to do it with minimal hassle? Thanks in advance! :thumb:

Chris
Title: Re: Raising needles- possible with carbs in situ?
Post by: cboling on October 01, 2009, 01:56:18 PM
I believe you can simply remove the gas tank, pull the diaphragm up (with the needle) adjust it then replace the slide and diaphragm and slide. Replace the cap.
Title: Re: Raising needles- possible with carbs in situ?
Post by: The Buddha on October 01, 2009, 02:04:55 PM
Yea needles come out the top, remove top and pull the diaphragms and slides and needles.
Cool.
Buddha.
Title: Re: Raising needles- possible with carbs in situ?
Post by: BeerGarage on October 01, 2009, 02:55:47 PM
You don't even need to remove the tank.

centerstand
unbolt
scoot back
prop up
(http://beergarage.com/imgs/GS/Tank/118.JPG)

And if you tie a string to the stick and hide and wait patiently, you can use it to catch gearheads.
Title: Re: Raising needles- possible with carbs in situ?
Post by: ohgood on October 01, 2009, 05:32:21 PM
Quote from: BeerGarage on October 01, 2009, 02:55:47 PM
You don't even need to remove the tank.

centerstand
unbolt
scoot back
prop up
(http://beergarage.com/imgs/Suzuki/gasket/118.JPG)

And if you tie a string to the stick and hide and wait patiently, you can use it to catch gearheads.
LOL !


i was thinkin about how i'm clumsy and gas tank + battery = boom !
Title: Re: Raising needles- possible with carbs in situ?
Post by: PachmanP on October 01, 2009, 07:08:33 PM
Quote from: BeerGarage on October 01, 2009, 02:55:47 PM
And if you tie a string to the stick and hide and wait patiently, you can use it to catch gearheads.

Yeah I only fell for that one once...or twice...ok every darn time...
Title: Re: Raising needles- possible with carbs in situ?
Post by: chrishiggs on October 02, 2009, 12:49:06 AM
Thanks folks...now anyone got a suggestion on which notch to try? I guess I probably want to move the needle up one notch at a time? (Presumably this means that I actually move the circlip down the needle?) Thanks again

Chris
Title: Re: Raising needles- possible with carbs in situ?
Post by: the mole on October 02, 2009, 03:00:20 AM
Yes, if you want the mid-range mixture richer you want to raise the needle, which means placing the clip lower on the needle. :thumb:
Title: Re: Raising needles- possible with carbs in situ?
Post by: chrishiggs on October 02, 2009, 07:04:26 AM
Wow, what a difference! :D
Raised them by one notch and the flat spots gone- fantastic.
Now that it runs and revs smoothly I'll be looking at the front brake. Waiting for a PFM iron rotor to arrive courtesy of ebay so I'll hopefully be able to stop too! Thanks for the help guys.
Title: Re: Raising needles- possible with carbs in situ?
Post by: gregvhen on October 15, 2009, 10:01:23 AM
hey, since the stock carbs are so lean, can I raise the needle one notch even though ive never done a rejet, or will that have a bad effect?  I have stock air and stock pipe, and heard about raising the needle.
Title: Re: Raising needles- possible with carbs in situ?
Post by: chrishiggs on October 15, 2009, 10:08:49 AM
If you have a flat spot in the midrange (5-6k revs) it is worth raising the needles. I upjetted for a non standard pipe and still had the flatspot. After moving the needles up a notch it was gone and the motor now revs freely to the redline. If you don't have a flat spot you probably don't need too. If you live in a very hot climate it might be worth doing to make the motor run slightly cooler. Bear in mind if you upjet your fuel consumption goes up!
Title: Re: Raising needles- possible with carbs in situ?
Post by: Birdmove on October 16, 2009, 03:33:07 PM
    Do the newer GS500s have grooves and clips? My 1980 GS425ST didn't. I had to remove the carb slides and shim the needles.But it ran great afterwards.

  Jon in Puyallup
Title: Re: Raising needles- possible with carbs in situ?
Post by: The Buddha on October 16, 2009, 03:42:52 PM
Euro bikes do, US dont. None of them do, unless you get a DJ type crap.
Cool.
Buddha.