I found the GStwin website a couple of weeks ago...awesome!
Thanks to everyone who's posted tips and directions in the forum.
After reading a lot of the messages and links about cleaning and rejetting carbs I got up the courage to do it myself.
I've had the carbs cleaned and tuned up at the dealer a couple of times over the years.(I bought the bike new)

I got everything back together and set the air mixture screws at 2 turns out.
The bike fired right up.
But now I can't tell if I'm going in the right direction with setting the mixture and idle.
I fiddled with it so long that I got frustrated with 1/2 a turn this way and that until I think the bike got too hot to get a good adjustment.
I let it cool down and started over.
I closed the mixture screws all the way and tried to start it - nothing.
I opened each a 1/4 turn at a time until it fired but wouldn't idle.
A few more 1/4 turns at a time and it now idles ok, but I am only about 1 full turn out at the moment.  Other folks have said 2-3 turns was where they started.( by the way I checked one carb before I took it apart and the screw was at 4.5 turns. It won't even start at 4.5 since the rejet.

Tell me if I  am thinking about this the right way.
When the air mixture screw is turned all the way in, does that mean that the air supply is shut off so that it is rich?
Opening the screw adds air and leans out the idle mix.

Here's what I did during the re-jet:
#40 pilots
125 mains
1 #4 washer on the needle(I put it under the doughnut instead of between the clip and doughnut if it makes a difference)I think it will accomplish the same effect there.

I will be going back in to the top of the carbs because the tiny O-ring under the cap looked pretty bad.  I ordered some, should be in next week.

Thanks for any suggestions,
Charlie
Woodland Hills, CA
When I get this worked out, I'm looking forward to an Angeles Crest ride, most of the time I ride on Mulholland hwy and the canyons because it's right out my door.

i think you are saposed to put the washer under the c clip

Welcome!

Quote from: cannoniv on May 21, 2006, 07:12:02 PM
I got everything back together and set the air mixture screws at 2 turns out.
The bike fired right up.

Good! 

Quote from: cannoniv on May 21, 2006, 07:12:02 PM
I let it cool down and started over.
I closed the mixture screws all the way and tried to start it - nothing.
I opened each a 1/4 turn at a time until it fired but wouldn't idle.
A few more 1/4 turns at a time and it now idles ok, but I am only about 1 full turn out at the moment.  Other folks have said 2-3 turns was where they started.( by the way I checked one carb before I took it apart and the screw was at 4.5 turns. It won't even start at 4.5 since the rejet.

Sometimes that's exactly what you have to do...start over, but you're already on the right track, so you don't have to start over.

Quote from: cannoniv on May 21, 2006, 07:12:02 PM
Tell me if I  am thinking about this the right way.
When the air mixture screw is turned all the way in, does that mean that the air supply is shut off so that it is rich?
Opening the screw adds air and leans out the idle mix.

It is a mixtrure screw, which means it adds both air and fuel.  Typically, screws mounted low on the carb are idle screws, which means they meter fuel only, but ours has its own air jet (if you trace the passsage through the carb body) which means that air is added.  The mixture is more fuel than air.

Quote from: cannoniv on May 21, 2006, 07:12:02 PM
Here's what I did during the re-jet:
#40 pilots
125 mains
1 #4 washer on the needle(I put it under the doughnut instead of between the clip and doughnut if it makes a difference)I think it will accomplish the same effect there.

As long as the washer is below the clip.

Quote from: scratch on May 22, 2006, 10:32:35 AM

Quote from: cannoniv on May 21, 2006, 07:12:02 PM
Here's what I did during the re-jet:
#40 pilots
125 mains
1 #4 washer on the needle(I put it under the doughnut instead of between the clip and doughnut if it makes a difference)I think it will accomplish the same effect there.

It does.

The only difference being that you have to keep track of the washer if you take the carbs apart. 

Thanks for the replies.
At least I feel like I've made some progress.

Egaeus is right about keeping track of the washer.
I had trouble getting the needle back in without the washer dropping off.
Of course I had it all back together before I realized my mistake. I will be changing that  when I replace that tiny o-ring.   

Scratch- you say the mixture screw  adds both fuel and air.  Is it a constant ratio? Because I thought I had to change the ratio of fuel to air to make it richer or leaner.
Tell me if this is correct:
The mixture controlled by the screw is what passes through the Pilot Jet, so that at idle the engine is running 100% on the mixture through the Pilot jet but as the throttle is opened it becomes a smaller percentage of the total fuel/air mix getting to the engine because the main jet adds a lot more.

By putting the washer on the needle are we opening the main jet slightly at idle as well, or is it more like opening it sooner and wider during acceleration?

I think I'm gonna stay with the small increment method of adjustment(1/4 turn at a time) today,
because I don't know what kind of result to expect and I'm still trying to get the concept of rich(bogs down) and lean(high idle that won't drop down)

I'm reading chapter 3 in the Clymer manual and then headed back out to the garage to check the fuel level in the bowls  and hopefully for a test ride.

Thanks,
I don't feel quite so alone in the garage now.
Charlie

Quote from: cannoniv on May 22, 2006, 03:27:47 PM
Egaeus is right about keeping track of the washer.

I edited my previous post. 
 

Quote from: cannoniv on May 22, 2006, 03:27:47 PM
Scratch- you say the mixture screw adds both fuel and air.  Is it a constant ratio? Because I thought I had to change the ratio of fuel to air to make it richer or leaner.

Yes, it is linear, but remember it adds more fuel than air, you're richening no matter what.

Quote from: cannoniv on May 22, 2006, 03:27:47 PM
Tell me if this is correct:
The mixture controlled by the screw is what passes through the Pilot Jet, so that at idle the engine is running 100% on the mixture through the Pilot jet but as the throttle is opened it becomes a smaller percentage of the total fuel/air mix getting to the engine because the main jet adds a lot more.

Nope, they are seperate; you will note that the mixture screw is downstream of the pilot jet; look where the holes are in the venturi.

Quote from: cannoniv on May 22, 2006, 03:27:47 PM
By putting the washer on the needle are we opening the main jet slightly at idle as well, or is it more like opening it sooner and wider during acceleration?

Kinda, it makes the needle open sooner (richer).

Quote from: cannoniv on May 22, 2006, 03:27:47 PM
I think I'm gonna stay with the small increment method of adjustment(1/4 turn at a time) today, because I don't know what kind of result to expect and I'm still trying to get the concept of rich(bogs down) and lean (high idle that won't drop down).

Wise.

The bike is running like a champ.
Advice is: while you have it apart, replace everything that is perishable.

I think my problem was a vacuum leak due to an old O-ring at the vacuum port (the little tiny O-ring, $3 at the dealer)
When I took apart the carbs I noticed that the O-ring was in bad shape but seemed intact.
I finished the work and put everything back together because I didn't have the parts to replace everything.
I struggled for several hours over a couple of days trying to dial in the mixture screws.

Today I replaced the  the O-ring and moved the washer (1 #4) so that it is between the doughnut and clip on the needle.
The doughnut was not as tight on the needle as I expected and slipped down as I was trying to replace the needle in the slide.
The bike is 17 years old, so some looseness may be expected.
I  tightened the clamps on the  airbox and engine sides of the carb, just for good measure.

I reset the mixture screws to 2 turns out and fired her up.
The idle seemed to hang a little bit after I blipped the throttle.
I first turned the idle speed adjuster down and then set the mixture screw 1/4 turn richer(out)

Test ride was next.
Throttle response was good. No  hesitation.
I did stop after about 20 minutes to readjust the idle speed.( again down a little to around 1200 rpm)

I am so relieved that I didn't screw something up besides not being prepared for replacing more parts.

Does anyone know where to get things like  fuel line at less than dealer(stealer)  cost.
I paid  $10 dollars for about 15 inches of fuel line because it has a  custom preformed bend at one end.
They charge the same for 20 inches without  the bend.

I am psyched now that the bike is running well again.

Thanks to everyone for the help and motivation.
When's that Angeles Forest ride Pantablo?

Charlie

Congradulations on a job well done!    And, I'm glad you're satisfied, you did the work yourself! 

charlie, where did you get the #4 washer???

i am in the valley and could use some help

call me 818-512-4047.. i havent run my bike in almost a year.. so its due for some stuff.

Good Guy,
     I bought 4 washers at Rudy's Ace hardware on Ventura for about a buck.
I had some really good luck finding the jets for this project, so I gotta tell this story.
First I called Mikuni headquarters in Northridge to try and find the local dealer/retailer with the best inventory in stock.
I didn't want to waste a half day or more going to Sudco who is the big local as well as onlline distributor, I think they're near Anaheim.
He suggested Kolbe Honda, again on Ventura Blvd, just 10 min. from home.
I found a great guy in the parts department named Dave who found the main jets in stock.
The pilot jets however he didn't have. 
He called the same rep I talked to at the Mikuni headquarters and the Mikuni guy brought him 2 pilot jets the next day.  No Charge.
I'll give you a call, what's a good time?

You must have another bike to ride eh? 
Some of your posts on http://gstwins.com/gsboard/index.php?topic=13148.0 rejetting were what got me motivated for my project.
I'm feeling confident now...I may have to start on that kitchen remodel I keep promising the wifey.
Charlie