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Main Area => General GS500 Discussion => Topic started by: Thrillwill352 on May 19, 2014, 05:49:13 AM

Title: Rejetted now too rich
Post by: Thrillwill352 on May 19, 2014, 05:49:13 AM
So I rejetted for a k&n lunch box and slip on exhaust 150 mids and 3 turns of the air fuel mixture screws and 2 washers but now it seems way too rich I have trouble keeping if running and any time I touch the throttle it'll rev up for about a second and then die, I plan on double checking the float heights but other than that I'm not sure what to do I'm just trying to keep my bike outta the shop any advice is appreciated! -Will
Title: Re: Rejetted now too rich
Post by: Meuryn on May 19, 2014, 07:21:22 AM
With a K&N lunchbox and Delkevic slip on I jetted to 20/62.5/142.5 with 2.5 turns out on the mixture screws and (I think) one notch down on the needles and that worked absolute wonders. Don't know if you've got a 2 jet carb, which might be different, but 150 seems a bit high?
Title: Re: Rejetted now too rich
Post by: Thrillwill352 on May 19, 2014, 07:38:03 AM
Yea 2 jet it's a 95, it's what the Buddha recommended, one notch down on the needles? Are you referring to the clip position on the needles?
Title: Re: Rejetted now too rich
Post by: dennisgb on May 19, 2014, 10:55:40 AM
Your description sounds like a pilot circuit issue.

Pilot screws should be adjusted with engine hot and set one at a time. Engine speed when adjusting controls position. Manual recommendation means nothing...it is a start position when rebuilding carbs (to get the engine running). Adjust each screw to get highest RPM and then set the idle speed to proper rpm. Each engine will be different so what one person did means nothing for where the screw will end up. If the screw is out past 3 turns then your pilot jet is too big...if the setting is 1 turn or less then your pilot jet is too big. Some recommend turning screw in 1/4 turn from highest rpm setting...don't think that makes much difference.
Title: Re: Rejetted now too rich
Post by: Meuryn on May 19, 2014, 11:32:56 AM
Quote from: Thrillwill352 on May 19, 2014, 07:38:03 AM
Yea 2 jet... one notch down on the needles? Are you referring to the clip position on the needles?

Oh disregard then :) Yep, I think it was down, although thinking about it, might have been up. Whichever way it's supposed to go, that's where it went  :D
Title: Re: Rejetted now too rich
Post by: Thrillwill352 on May 19, 2014, 11:51:18 AM
Yea I figured it would need adjusting but I didn't think I would have trouble getting it running, so right now the plan is deconstructing and reconstructing carb to make sure everything is right and check the float height, I would adjust the pilot screws while running but it's not very easy to access while mounted, is going  to 2.5 turns and 1 washer a good start? 
Title: Re: Rejetted now too rich
Post by: Thrillwill352 on May 19, 2014, 03:43:34 PM
Anyone know if there is a usual tuning ritual after a rejet?
Title: Re: Rejetted now too rich
Post by: Funderb on May 19, 2014, 04:05:46 PM
you already know to check float height first.

What pilot jet size do you have in there?
What kind of slip on do you have?

my 98 had a lbox and akrapovic slip, i ran 40 pilot jets, 2.75 turns on the screws and 147.5 mains for the perfect mix.
actually, my set up should be in my signature line. read that.

if you have stock pilots you are overwhelming them. if you didnt oil the K&N you're also not going to get the mix right.
I would guess that you're too fat on the mains and too lean on the pilot (if you have the 37.5s in)
Title: Re: Rejetted now too rich
Post by: Thrillwill352 on May 20, 2014, 04:44:27 AM
Well I didn't have time to check the float heights but I realized I had accidentally put the donut on the wrong side of the needle  which was my problem, I was actually able to get it running and ride for a min now just the fine tuning left!
Title: Re: Rejetted now too rich
Post by: Thrillwill352 on May 20, 2014, 04:46:45 AM
Also anyone know what size the stock fuel lines are? I plan on replacing them and getting a new tank petcock eventually
Title: Re: Rejetted now too rich
Post by: BockinBboy on May 20, 2014, 07:33:18 AM
That's a tricky question because... the tank petcock is smaller diameter than the frame petcock... and they are technically metric sizes as well (like 6 and 7mm or something like that)...  So its a toss up if you use 1/4 (tighter) or 5/16 (looser), but many members here support use of tygon hoses in either size.  1/4 is great fit for tank, but pretty tight for frame... where as 5/16 is great fit for frame, but loose for tank... Or you go OEM, and know you won't have an issue.  Whatever you use make sure it is suitable for gravity fed systems, as fuel injection type lines and most regular automotive lines will be much too thick for the tank petcock.

- Bboy
Title: Re: Rejetted now too rich
Post by: Thrillwill352 on May 20, 2014, 07:38:39 AM
Exactly what I was lookin for thanks man!