Question about an air screw

[tanglefoot]

1981 GS850G with CV carbs. About four years ago I was planning a road trip and didn't have time to rebuild my carbs.,so I took the bike to a Suzuki dealer and had the carbs completely rebuilt and syn. The bike logged over 3500 miles and never a problem. After the trip and due to a job asignment I was forced to put the bike in storage which lasted for almost three years. Now I am ready to put the bike back on the road. I have done everything that should be done and now I am going to rebuild and clean the carbs. Now here is the problem----In tearing down and getting ready to soak and install new kits in the carbs, the air screw in #2 carb has half of the "screw driver" slot missing. Like it has been broken off. Does anyone have any suggestion on how to remove the air screw. I have tried everthing I know and have had no luck. I can't get it to move at all. Any suggestions would greatly be appreciated. Thanks Guys.

[rcp]

These are the steps that work for me:
1) Spray the air screw with some carb cleaner, then blow it out with some compressed air. This cleans out some of the dirt/varnish that might be sealing stuff, and lets you see better.
2) Spray with some penetrating lube, or at least some WD40.
3) With best fitting screwdriver, apply firm yet prudent downward force while attempting to turn. Stop if this doesn't appear to be working, or is slipping, or breaking the slot further.
4) If still stuck, put carb body on somewhat firm, but yielding, smooth platform - a piece of softwood, or plastic (I use my long allen socket blow-moulded case); take good-fitting, nicely-square-edged slot screwdriver, and insert into (remains of) slot; take light mallet or plastic hammer and give a firm yet prudent rap to the handle of the screwdriver - this should set a new groove into the soft brass jet body. Turn it out, throw it away and replace.

I've only every had to go to step 4 for pilot jets.

- Richard

[Steve]

Another option is to use a Dremel tool with a narrow cut-off wheel to cut a deeper groove in the screw. Yeah, you also cut a groove down the entire length of the tower that holds the screw, but I have not had any problems with that.

Hopefully you did not waste your money on 'rebuild kits'. For less than the cost of ONE of those kits, you can have all the o-rings you need to rebuild your carbs after dipping them. By the way, if it has been stored for ... what? ... three years? ... do yourself a favor and dip each carb body overnight. Yeah, it takes longer that way, but you will only have to do it once. If you do shortcuts while doing the carbs, you will only have to do it again. New o-rings kits are available from fellow GSR member Robert Barr at www.cycleorings.com. Price is about $15 and includes more o-rings than you get in the kits. The kits don't include many of the o-rings that you need, and you would have to buy them, anyway.

One last thing, the screw you are trying to remove is technically not an "air screw", it is the "idle mixture adjustment screw". The idle mixture is pre-set by the pilot air jet in the intake of the carb throat and the pilot fuel jet in the bottom of the carb, next to the main jet. The mixture adjust screw adjusts how much of that pre-set mixture gets to the engine.

Because it adjusts a mix of air and fuel, turning it OUT will richen the mixture that gets to the engine, while turning it IN will lean it out. When you get the carbs back together, start with these screws between 2 and 3 turns out from lightly seated.

.

[BassCliff]

Greetings and Salutations!!

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BassCliff

[tanglefoot]

Thanks for the welcome and also thanks for the input you guys have given me on the carb rebuild. I have in the past done all the work on the bike myself. This (1981 GS850G) bike was bought when it was still in the crate in 1982. It has well over 200,000 miles with an engine rebuild at 97,500 miles. I have done all the work myself and have overhauled the carbs. at least five times. This one time getting the carbs. overhauled at a dealership is what has "bogged" me down. They really did a number on the carbs. In the process of tearing down the carbs. I have found other things goofed up by them.

[janksolid]

I just removed an air screw today. After nearly demolishing the head and only getting it out a couple of turns I ended up very carefully drilling a hole down about 1 centimetre in to it , starting with a smaller pilot hole. I then got a Torx bit which was a nice tight fit and hammered it firmly into the hole. Put an electric screwdriver on it and screwed it right out :-)

[Larry D]

You can always look around for another #2 carb body and worry about getting it out later. Someone here may have one in a parts box.

[janksolid]

Anyone know where I can get replacement air screws in the UK?

[BassCliff]

Anyone know where I can get replacement air screws in the UK?

Hi,

Maybe http://www.cmsnl.com ? I wouldn't know of any local dealers since I'm way over here across the pond.


Thank you for your indulgence,

BassCliff

[donimo]

yours seems to take the same one as mine, pretty common part it seems (not 100% this is your bike):

http://www.cmsnl.com/products/13279-47070-screwpilot-1_1327947080/

suzuki dealer should still stock it...

[janksolid]

yours seems to take the same one as mine, pretty common part it seems (not 100% this is your bike):

http://www.cmsnl.com/products/13279-47070-screwpilot-1_1327947080/

suzuki dealer should still stock it...

That's it! Wow, thanks.
Just couldn't find the part number before.
Robinsons have got them.