Carb Bench Sync

[Skyboy8950]

Hey guys,

So I am about to reassemble my carbs from my 82 GS650GL (just waiting on a part or two) and would like to know how to bench sync my carbs so when I fire it up, it is close to what it needs to be. I have found out how to calibrate the floats and I also know to start with the air screw 1.5 turns out. Please let me know if you have any further insight. Thanks.

[gustovh]

do a search on carb synk or use the carb cleanup series at the bottom of the left hand links on the home page. Everything you need should be there.
V

[Steve]

The quick idea is to turn the master idle speed control until a small (1/16" or so) drill bit will just barely slide through the throttle opening on carb #3, which is the 'master' carb. Then use the adjusters between the carbs to adjust #4, #2 and #1. Make sure you do #2 before #1 because #1 slaves off of #2.


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[SqDancerLynn1]

ditto::: also when the idle screw is backed out make sure # 3 is closed

[MadMAx13]

How do you calibrate the floats?

Hey guys,

So I am about to reassemble my carbs from my 82 GS650GL (just waiting on a part or two) and would like to know how to bench sync my carbs so when I fire it up, it is close to what it needs to be. I have found out how to calibrate the floats and I also know to start with the air screw 1.5 turns out. Please let me know if you have any further insight. Thanks.

[Skyboy8950]

http://www.thegsresources.com/_forum/showthread.php?t=107132

This is one way to test the float heights. I plan, rather, on measuring the float heights from the body of the carb (without gasket installed) to the top end of the float where the metal goes into the float. Also, the float should be sitting on the needle, but not compressing it. Also, if you go the thread that has carb specs per model, you can find what you need to set your floats to, along with other helpful info.

Hope this helps. Can't wait to get my last few parts...

[Steve]

I think that is a good way to verify that all the floats are the same, but it would not be accurate at all for calibration of proper height.

As mentioned in the write-up, the floats and main jet would displace some fluid, raising the level. When the bowl (with gas in it) is removed, the level would drop a bit. When specs for gas level are given, it is assumed that the carb is on the bike, ready to run. It would be more accurate to put the drain screw adapter in and measure the level against the side of the carb as specified in the manual.

The recommended method to set the float height is to turn the carb over, remove the bowl and gasket, measure from the gasket surface of the body to the top of the curve of the float, not to the top where the metal tang is. Including the depth of the mounting tang will raise your fuel level and cause the bike to run a bit rich.


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[Skyboy8950]

Steve,

Excellent post. My question is this. Would it be appropriate to measure the float height and set them to spec and assume this will give us the proper gas level? Also, could you please explain the drain screw adapter? Thanks.

[Steve]

The Suzuki manual gives instructions for setting the float level, then checking the fuel level while running, so I suppose both of them are important. However, I don't know very many people that have checked the fuel level while running. As long as your floats are still sealed (shake them to see if there is any fluid in them), they should be OK. You will probably be fine with just the float adjustment.


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[Skyboy8950]

Thank you Steve, I will continue as planned, but really good information...