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Main Area => General GS500 Discussion => Topic started by: Amigo1342 on March 10, 2011, 01:34:51 PM

Title: Can someone help with rejet info please
Post by: Amigo1342 on March 10, 2011, 01:34:51 PM
Hey guys long time viewer first time poster.  I had a question about rejetting
settings. 

I have an 09 gs500f. I purchased the lunchbox
k@n and a yoshi slip on pipe and was wondering what specs to rejet to. I've used the matrix on the wiki to help but not too much info is for that specific setup. I'm sure people are using the same I am and I was curious whatto rejet to and where I could get a kit from that would include all the stuff I needed.

Any help would be greatly appreciated.
Title: Re: Can someone help with rejet info please
Post by: The Buddha on March 10, 2011, 02:01:46 PM
Piece of cake, 20, 147.5, 1-2 washers, 3 turns.
Buddha sell ... $25 shipped in US.
If you want mids, those are 65's and they would add $8 ...
Cool.
Buddha.
Title: Re: Can someone help with rejet info please
Post by: Amigo1342 on March 10, 2011, 03:37:09 PM
Might as well do the mids too haha. Ima have a mechanic rejet for me. I should be able to tell him the specs and give him the kit and have it done. I hope anyway =X
Title: Re: Can someone help with rejet info please
Post by: ke7syv on March 10, 2011, 07:58:38 PM
Would the washers still be needed if the mids are replaced?
Title: Re: Can someone help with rejet info please
Post by: Amigo1342 on March 13, 2011, 06:49:55 AM
Yeah that's a good question
Title: Re: Can someone help with rejet info please
Post by: ke7syv on March 13, 2011, 01:16:26 PM
Thats why I posted it.
AFAIK, the needles interact with the mid jets. By adding washers your allowing more fuel flow because the tapered needle is now sitting higher. The same thing can be achieved by replacing the mid with a larger one and leaving the needle in the same position (Height). The only question I have is how many washers equal a step up in jets? e.g. does a  62.5mid + 2 washers = 65mid
Title: Re: Can someone help with rejet info please
Post by: Unsane on March 13, 2011, 02:46:41 PM
The main jets are directly under the needles - at least they do on my 05! There was nothing behind the mids.

I have the same setup as you Amigo, but with a Screamin Demon slip-on... I can't imagine there would be too much difference in flow compared to the Yoshi (just build quality!)
I went 20 pilot, 65 mid and 145 mains - have not adjusted anything else - no washers, no idle jet adjustment, no rebuild... just ripped the carbies off, removed the fuel bowl and changed the jets - took me an hour and it was done. Runs much better in the mid range to top end but low end might do with some improvement. Will experiment with washers when I get access to dyno and gas analyser as I dont think it would be possible to feel the difference riding down the road.
Title: Re: Can someone help with rejet info please
Post by: ke7syv on March 13, 2011, 08:40:58 PM
http://gstwins.com/gsboard/index.php?topic=43853.0

Pilot----? 0-1/8th throttle. Typically take off rideability is adjusted with this. Ilde is adjusted with Turns out ... but they both control 0-1/8th throttle.

Mid-Main---? 1/4-3/4

Main---? 3/4 throttle and up

Needle Shim---? (washers on needles) Needle controls 1/4 to 3/4 throttle, shimming them lets a smaller diameter serve as an obstruction in the emulsion tube. So it stays at 1/4 to 3/4 throttle for effect, but acts like its a hair more open than it is without the shim.

Turns out---? Idle and take off, and adjust it for idle but take off also can be affected. If you cant get one right without screwing the other ... 1 on a GS, you doing it wrong or some crap is clogged up or the carbs are waaaaaay off balance or the synch is really off, or valves are not closing or you have an intake or exhaust leak or some electrical sheite is broke, or you dont even have a GS and are wasting our time. ... but in case that happens on a hypothetical bike, and you dont want to send it to buddha ... you will notch the butterflies ... and depending on what you're seeing, you'd notch it in a different spot - top or bottom ... but remember, this is the equivalent of an atomic bomb to kill a cockroach.

1. float level ... that is mainly as you open the throttle between 1/4 and 1/2 throttle. You cannot really adjust it, its gotta be set within 1-2mm ... else its can be a disaster ... but it does affect this.
2. Slide hole - open the throttle fast and it falls on its face, open slow and it revs up nice and good under high load. Slide needs to have 1 hole blocked and may be other one partly closed

Title: Re: Can someone help with rejet info please
Post by: tt_four on March 13, 2011, 08:58:46 PM
People always talk about main, mid, and pilot jets, and even though I've completely pulled apart and rebuilt my carbs about 10 times I still have no idea which ones the mid jets are...

I know these two....

(http://electrovw.tripod.com/sitebuildercontent/sitebuilderpictures/jets.jpg)

but where is the mid?


Is Screamin Demon the brand of the exhaust?? that's an awesome name haha. My bike has a lunch box and a V&H full exhaust and I've got 135s. Not sure if that's right or not but it seems to run well.
Title: Re: Can someone help with rejet info please
Post by: Unsane on March 13, 2011, 09:20:46 PM
Here are the jet positions (not my pic - props to the person who took it though!)

(http://i258.photobucket.com/albums/hh253/teknoblast/GS500F/Carbyjets.jpg)

Yeah Screamin Demon... awesome name and awesome product!
http://screamingdemon.com.au/index.php?main_page=index&cPath=190_195_385 (http://screamingdemon.com.au/index.php?main_page=index&cPath=190_195_385)
Title: Re: Can someone help with rejet info please
Post by: ke7syv on March 14, 2011, 12:18:48 PM
Quote from: tt_four on March 13, 2011, 08:58:46 PM
People always talk about main, mid, and pilot jets, and even though I've completely pulled apart and rebuilt my carbs about 10 times I still have no idea which ones the mid jets are...

I know these two....

(http://electrovw.tripod.com/sitebuildercontent/sitebuilderpictures/jets.jpg)

but where is the mid?


Is Screamin Demon the brand of the exhaust?? that's an awesome name haha. My bike has a lunch box and a V&H full exhaust and I've got 135s. Not sure if that's right or not but it seems to run well.

Thats cause you have the older 2 circuit carbs(pilot and main). Everything here applies to the newer 3 circuit carbs that came in the 01' and later. The thing I don't understand is, how come the needles interact with the main jets yet they affect 1/4 - 3/4 throttle? Seems kinda contradicting to me.
Title: Re: Can someone help with rejet info please
Post by: The Buddha on March 14, 2011, 12:27:36 PM
With a DJ or other "jet kit" you end up with weird sizes of mains, like I've seen 134 ... wtf 134 ...anyway they have funky numbers, 134 may not be the 1.34mm dia its supposed to be if you use mikuni numbers, and the other crazy thing is that needle is an obstruction in the emulsion tube, the main jet is @ the inlet to the emulsion tube. Putting in a thinner needle (which the kits provide) means you can put a smaller main jet and get the same flow rate.

147.5 or whatever I say as the right jet for your setup is all with the stock needle. If you dont have stock needle, you cant use my formula.

Mids are only in the 01+ carbs, and they are 1/2 way up the stack ... lowest is main, highest is pilot, mids are in the middle.
Swapping mids can eliminate the need to run washers, but well, washers are OK too ... mids are usually a rare case where they are needed.

Cool.
Buddha.