Swapping carburetors by Richard Cook
	Mikuni type carbs, 28mm at the manifold and 26mm at the rear of the throttle body fitted to an M1S These Chinese copies lack the fit of the older Mikunis I had many years ago. With no directions included there is a certain amount of guessing how things go. I was unable to find any good directions to go by. Be sure to shut off the gas and run the bike until the carbs empty. George offered advice on the breather tubes and the way I have them now is temporary until I have determined if I am really happy with them. If they stay on the bike I’ll route all breathers over to the frame since George pointed out that a flooded float is going to soak your shoe in gas, possibly more excitement then I need. I had two kits handy, one from Angie and one from Dan. I was missing a couple of bits so I mixed and matched to get one good kit. 1)   First lay out the parts and see if you have two of everything. 2)   If you look at the cap picture you will see a small round O ring type gasket. The only place I can see it fits is that groove, but it refuses to stay there in all four carbs. I used silicone seal to hold the gasket in place and let it set while I pulled the stock carbs. 3)   Remove fuel line and air cleaner hoses. 4)   Unscrew the carb tops and disconnect the slides. I use a screwdriver to slide the spring out and then needle nose pliers to grip the cable. The cable has to come out straight and will lock if you have it on an angle, so feed it out with a little whip in the cable. 5)   The carbs come off easily with two nuts apiece. Then screw the nuts back on and tighten the nuts on the stud with two wrenches. Use the lower nut to unscrew the studs. 6)   Now it will be easy to clean the carb surfaces on the head. One of my studs had been slightly stripped and one stud had pulled up some alloy, so I dressed the area with a file and retapped. 7)   Now place one gasket on the head and install the rubber carb adapter with the notches up to match the carb. I put a small amount of Locktite blue on the allen screws.Tighten the hose clamp and the carb body is on. 8)   Install the adapters in the order shown in the throttle cable picture. There is a small white plastic circle that appears to fit under the spring and I reckon functions like a lock. Insert the slide in the carb body carefully. If it seems to hang up start again to avoid damage. Use care starting the threads on the carb top as many folks have stripped these. 9)   Now you should be up to extending the air cleaner hoses. As you can see in the picture the stock ones may have been for a flathead and don’t come close to fitting my bike. I used some old BMW radiator hose and a vacuum cleaner extension to get mine to fit. I have not yet fastened all the hose clamps as I may be playing with adjustments for a while. I also had to slightly extend the fuel line. I have started with all stock jets and slide adjustment as from the information I have found they seem about right. The bike started right up using the usual turn and a half on the mixture screws and the slides just open. I will carefully chart any changes. After a minor tune on this 90 degree day I took the bike for a ride. It runs about as well as the old carbs with a little less burble at low speeds. I had been chasing a stumble and that is gone on these carbs. So far the only really noticeable change is there is more instant power available in the mid range.