Do my carbs have pilot fuel screw?

[eastern]

I have the day off of work and was just about to do my first carb rebuild on my 1980 GS550L. I was getting everything ready and was remembering that mixture screw (underneath the metal plug on top of the carb) would need to be reset to 1.5 turns to start with (or at least a lot of people recommend that here). I thought this would be the only screw that would need to be backed out and recorded but it appears everyone is talking about the confusion of the pilot fuel screw as well.

So I looked at the carb oem specs manual and it shows the 80-82 550 to be 3.5 back for the pilot fuel screw. Does that mean it needs to be backed out 3.5 turns? Where exactly is the pilot fuel screw on my model? The carb rebuild pfd doesn't mention it.

A little confused and now wondering if I should embark on this rebuild.

[Bopi]

Funny stuff, I seem to be going thru the same thing right now. Maybe my book is calling the pilot fuel screw a "mixture screw" and is calling the air screw a "pilot air jet" hence the confusion. It also lists the setting for the mixture screw at 1 turn out but doesn't list "turn out" for the air screw but simply lists a 1.5 number.

Anyway thats all the help i can offer you but I will say that my rebuild took about 4-5 hours and a can of carb-cleaner and a can of compressed air. I've started and run the engine briefly after the rebuild so something must have gone right. I'd go for it. If i'm not mistaken, your model has diaphrams which need extra care in handling and inspection. Perhaps someone else has more insight.

( note; the shop wanted $200 plus for the rebuild)

[mark]

http://www.thegsresources.com/gs_carbrebuild.htm

This should help if you haven't looked at it yet. Its 850 carbs, but basically applies to yours as well.

[rickt]

The turns for pilot air and pilot fuel screws refers to the number of turns out from being fully seated. So, the procedure is to carefully turn the screw in - counting the number of turns - until the screw is gently seated. The key word is "gently" as it is possible to jam the needle point into the tiny hole and then have the screw break off when you try to remove it. This happened on three of four carbs during my rebuild ('78 GS750C). These carbs sat for 26 years with residual gas and the needles were badly corroded. After failing to remove the broken tips, I sent the carbs to a shop and had them drilled out. This was EXPENSIVE. When you have the carbs completely stripped, give them a couple of hour bath in a powerful carb cleaner (e.g. Gunk or Berryman). Then, spray them good with aerosal carb cleaner and blow them dry. Replace o-rings as needed and turn screws in until "gently" seated. Then, back the screws out the same number of turns you noted when removing them.

Hope this helps!

rickt