Posted by Davo on July 16, 2001 at 17:08:25:
...er, I mean I removed the infamous white spacer this weekend. It was not a terribly tough job. The gas tank was the usual hassle to get off. I wonder if Suzuki installs the petcock after mounting the tank?
Anyway, I did not need to remove the carburetor. The four screws holding the top cover on the carb were as tight as a...never mind. I ended up using an impact wrench. I'm not talking about a Sears jobbie that you smack with a hammer; I'm talking about a honkin' half-inch drive air impact wrench. Actually, it was mostly the weight of the wrench holding the tip in the groove that did the job. Spend the time to find a tip that fits perfectly in the head of the screw.
With the cover off, the slide and diaphragm come out easily. The spring comes out totally on its own. :) The screws holding the needle cover plate in place were put in by Charles Atlas himself, so searching for a tight-fitting implement again pays dividends here.
Removing the spacer is equivalent to moving the needle clip lower (and the needle higher) on other carburetors. The result is a richer fuel-air mixture.
When putting things back together, make sure the little "tit" (sorry ladies, I don't know what else to call it) on the needle plate faces down. Its function is apparently to prevent the needle from rotating. Also make sure that the needle is free to move up and down under spring tension within the slide.
When returning the diaphragm and slide to the carburetor body, be sure to align the tab on the diaphragm with the recess in the carb body. I thought it would be a royal P.I.T.A. to get the carb cover back on, since the diaphragm doesn't like to sit with its lip neatly in place. However, once you move the cover into position, the diaphragm settles in properly. Apply light pressure to the cover and make sure there are no gaps around the perimeter; this indicates that the diaphragm lip is seated correctly.
I was fairly impressed by the difference in throttle response. After a brief road test, I decided to adjust the idle mixture as well. I adjusted the idle speed screw until the bike was just barely running, then I started backing out the idle mixture screw (it was all the way in). The engine will pick up a bit, and you can lower the idle speed again. After several iterations of this process, you will find settings where turning the mixture screw a half turn in either direction will cause the bike to stall. This is the ideal setting. Readjust the idle speed to the normal setting at this point. The optimum mixture screw position was 1-1/2 turns out from fully seated on my bike.
I feel that the project was definitely worth the time invested.
Ride safely,
Davo