Mixture screw adjusting tool

[49er]

Access to these screws is tight. The gap between the carb bowl and the top of the crankcase is miniscule.
Rather than shortening up a standard scewdriver which is near impossible to hold and adjust with, fashion one out of a piece of old hacksaw blade.
Break off a 2'' piece and grind a blade on one end to the width of the screw head and just deep enough to clear the surrounding casting. The hacksaw blade shape is easier to hold between your fingers and provides greater leverage when working in this tight space.

 

[Guest]

That's a great idea! :-D A solution I found is to take a 1/4" socket, "shim" it with some plastic wrap and shove a flat screwdriver bit in there. It's a little awkward to adjust #2 carb with it but it works pretty well.

 

[49er]

That's a great idea! :-D A solution I found is to take a 1/4" socket, "shim" it with some plastic wrap and shove a flat screwdriver bit in there. It's a little awkward to adjust #2 carb with it but it works pretty well.

Another advantage in using the hacksaw blade is you get a great visual guide when needing to make fine adjustments. Where ever the handle is positioned so is the blade.
I start with a mirror and draw the slot positions of each screw on a piece of paper, for the 4 carbs. I then turn each screw in until it lightly seats, counting the turns and recording them. From previous plug reads, I then adjust each mixture screw accordingly, followed by the air screws for the highest idle speed. Road test and read plugs again.

 

[mark]

Great idea. I've always used a set-up similar to what Peter uses, but that hacksaw blade would give you a better sense of how much you are turning the mixture screw.

 

[oldschoolorange]

Snap-on sells special flexible and 90 degree tools for adjusting carbs. I picked them up because I did not feel like ghetto rigging things up any more, that and they are pretty cheap too
http://buy1.snapon.com/catalog/item...0&group_ID=126&store=snapon-store&dir=catalog
http://buy1.snapon.com/catalog/item...5&group_ID=126&store=snapon-store&dir=catalog

 

[pasteurized]

My "tool" works fairly well - it's the end 2" of a flat head screwdriver that I cut off with a dremel. Only snag I have run into was going through security before flying home a year or two ago. The thing kept going off and I had nothing on me. It wasn't until I got out my wallet that I realized I had my "tool" in there for tuning while on a ride. I got some ridiculously suspicious looks when I pulled that thing out!

 

[Greg O.]

Good idea. Those things are a pain to adjust. What should the preliminary setting be for a 79 gs750 be?

Greg O.

 

[49er]

Greg. I haven't visited this thread for a while.
With the VM's on your 750, the fuel mixture screws should be some where in the 5/8 to 1 turn region. My 850 carbs were all factory set at 3/4 turn off the seat. I estabablished this by matching the screw positions to the paint sprayed on them. A recent post by another member said that the GS 1000 Suzuki Service manual quoted the fuel mixture settings for bikes fitted with VM 26SS carbs at 5/8 to 7/8 off the seat. Hope this helps.
Cheers
Ian

 

[pauly]

I have a small screwdriver bit epoxied into a toothpaste cap. Works like a charm.

Cheers
Paul

 

[trippivot]

carb tool

carb tool

I use a tool called "carb click" it is a short 90 deg. tool I got off the matco truck they sell it for 60-75 bucks very valuable! it is shorter than any other tool except the kawasaki special tool and a lot tougher than the kawa unit.

 

[chuckycheese]

Sewing machine

Sewing machine

I use a sewing machine screwdriver. They're all a little different but I think the Royal is the best. It's flat on one side so you can see how much you've turned it without any problem.

 

[Skyboy8950]

I use the flat head out of a 4-in-1 screwdriver. The screw is fairly loose, so you can spin it with your fingertips. It also is a perfect fit.