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Main Area => General GS500 Discussion => Topic started by: mattress on August 25, 2007, 01:28:01 PM

Title: engine running rich, what needs to be done?
Post by: mattress on August 25, 2007, 01:28:01 PM
40 pilots, 145 mains, 1 #4 washer on each needle, and 3 turns out on the mixture screw

K&N Lunchbox, drilled exhaust

I noticed the engine was missing (no jokes lol), so I pulled the plugs.  They're pretty fouled up and black.  So I'm assuming I'm running rich.

What do I need to do to lean it out? 
Turn the mixture screws back in a turn or 1/2 turn?
Title: Re: engine running rich, what needs to be done?
Post by: GSRider on August 25, 2007, 02:00:59 PM
Try your starting point at 2 turns, and adjust from there, in 1/4 turn increments.
Title: Re: engine running rich, what needs to be done?
Post by: mattress on August 25, 2007, 07:06:56 PM
ok, so replace the plugs.  turn the screws out 2 turns.

How can I tell if it's running right or not?  How long will it take to tell?
Title: Re: engine running rich, what needs to be done?
Post by: kml.krk on August 25, 2007, 09:52:54 PM
you could try changing the exhaust to some aftermarket high flowing one. also you could change the main jet to smaller, or remove the shims under the needle.
I'm not an expert though, just throwing the ideas
Cheers
KaMeL
Title: Re: engine running rich, what needs to be done?
Post by: mattress on August 26, 2007, 08:05:36 AM
Well, I did buy an R6 can, and it's been sitting in the closet for about a month now. 
I haven't decided if I want to use it yet.. 
A member on here Dax bought one too, and got it installed, but I haven't heard sound clips yet.


It's such a huge muffler, I don't want it to cause problems for passengers riding, and I don't know how much more free flowing it's actually going to be with the stock header

I'll try and mess around with it a little bit.  I guess it's not an exact science, more of a adjust, test, adjust, test until about right :)

Is it possible to adjust the screws without taking the tank and everything off?  I remember the screws being pretty tight, so I don't know if I'd be able to get a screwdriver in there upside down and turn them.
Title: Re: engine running rich, what needs to be done?
Post by: scotch_rocket on September 11, 2007, 02:38:20 PM
Hello there!  I'm running an 89 GS500E and the Idle adjust screws are SUPER easy to get to with a flat head BIT like for a multi purpose screw driver.   If you check out the POOR MANS REJETTING PICTORIAL page, ( http://www.angelfire.com/mt2/mikesgs500/rejetting/ ) there is a picture where he's adjusting his Idle screw with the same tool.  They're easy to find and no break down SHOULD be needed.  Good luck.  I'm also rejetting my GS and I think I need to adjust the needle height some more but I have a Dyno kit so they replaced the needle and not sure where the Starting point was but now it's trial and error time.  Happy riding!
Title: Re: engine running rich, what needs to be done?
Post by: coll0412 on September 11, 2007, 02:48:15 PM
So you actually have to be more specific on how your engine is missing. What RPM, what amount of throttle ect ect.

Adjusting the idle mixture screws will adjust your idle mixture, no good for anything above 1500rpm. So get back to us and let us know more about the bike and where is it missing.
Title: Re: engine running rich, what needs to be done?
Post by: mattress on September 11, 2007, 04:21:40 PM
you mean the air/fuel mixture screws that I had to drill the brass cap off of to adjust are just for idle?!

I didn't know that, I feel pretty funny now  :laugh:
Title: Re: engine running rich, what needs to be done?
Post by: Jay_wolf on September 11, 2007, 04:37:59 PM
There not ,the idle screw is like a lil stem with a lil wheel on there ,.


(_______)
      ||
      ||
      ||
      ||                 Thats what it looks like , upside down , the wheel is like from the engine , u twist it 2 make idle , sittin on the bike

turning to the right makes the idle increase ,to the left decreases it

Jay
Title: Re: engine running rich, what needs to be done?
Post by: spc on September 11, 2007, 04:52:51 PM
Actually jay,
the mixture screw does primarily affect your mixture at idle..........
Title: Re: engine running rich, what needs to be done?
Post by: Jay_wolf on September 11, 2007, 05:18:05 PM
well theres me using the Idle screw to adjust mine...  :dunno_white:

my bike runs perfect. im not touching the screws agen
Title: Re: engine running rich, what needs to be done?
Post by: scotch_rocket on September 12, 2007, 08:13:06 AM
Well I've been having some "Spitting" with my carb and I'm getting really tired of pulling that damned tank off.  Here is my set up.  40 Pilot, 147.5 Main Jet, Dynajet Needle clip set on 3rd space down (no Washers - didn't know the starting point), 3 turns out.  Now when she's warmed up and ready, it idles with some bump, not extremely smooth and it seems slow returning to idle.  When I take off she has some hessitation but nothing too alarming.  Now when I kick the throttle open, around 1/2 throttle it bogs and kicks and stops around 6500 rpms....but when I really open it up around 7000 rpms, she takes off like a F'n rocket.  When I let off the throttle and cruise around 5500 rpms she's a little jumpy and not smooth.  Any feed back on this problem?  Might help some others out there too.
Title: Re: engine running rich, what needs to be done?
Post by: coll0412 on September 12, 2007, 03:57:25 PM
For all future reference: if you want help you need to supply the following

1. What year, and what is your configuration(i.e airfilter, exhaust)

2. What and when is the problem(RPM,load ect)

scotch_rocket provided half of the info, but I will give it a go anyways.

If the idle is slow to returning to idle, it is most likely lean. Now it may be lean because there is a vacuum leak(from the boots or you forgot the oring that goes on the top of the carbs) and is letting air into the engine that doesn't get gas added to it. This causes it to be lean, the other option is that you need to adjust your mixture screws.

The other option is that the cable is hung up and not letting the throttle close all the way(maybe)

As far as the 5500-6500 lag, its a common problem, and first you need to figure out if you are lean or rich. I have in the past got to the rpm, gave it full choke and see if that helped or made it worse, if it makes it worse you are rich, if it helps you are lean.
Either way you need to adjust the clip of the needle, raise the clip to lean it out, lower the clip to make it richer.

Title: Re: engine running rich, what needs to be done?
Post by: scotch_rocket on September 12, 2007, 06:53:04 PM
Hello everyone!

Well I'd like to say thank you for your insight.  I got her running like a top now.  Raised the clip on the needle to the #2 position and it has a smooth transition.  I might tweak the mixture screws alittle, but she's running like she's supposed too.  So if anyone out there has a Dynojet kit needle, #2 is where to start and if you drop the clip down a position, you'll see the bog hessitation earlier. 

#2 - smooth
#3 - 5500 rpms hessitation starts
#4 - 4000 rpms hessitation starts
#5 - Runs like SH*T!!!

By the way, MATTRESS, hows you ride running now that you've tinkered with the mixture screws???
Title: Re: engine running rich, what needs to be done?
Post by: yamahonkawazuki on September 13, 2007, 12:56:30 AM
Quote from: Jay_wolf on September 11, 2007, 04:37:59 PM
There not ,the idle screw is like a lil stem with a lil wheel on there ,.


(_______)
      ||
      ||
      ||
      ||                 Thats what it looks like , upside down , the wheel is like from the engine , u twist it 2 make idle , sittin on the bike

turning to the right makes the idle increase ,to the left decreases it

Jay
jay thats the idle speed screw not the mixture screw, teh mixture screw is between teh carb and the engine ( mostly) yes behind the brass plug :thumb:
scotch, i had the same setup pretty much with my 97, but i set my mixture screws at 2.5 turns out :thumb: