How to Rebuild and Clean 1980 Yamaha XS850 Motorcycle Carburetors

I rebuilt and cleaned 1980 Yamaha XS850 motorcycle carburetors.

Supplies

Screwdrivers, wrenches, a locking plier, gloves, carburetor cleaner, safety goggles, etc

Step 1: Get a Manual and Stay Organized

I photocopied the manual and cut the instructions into pieces. Then, I pasted them on a large foamboard with relevant diagrams. When parts were removed, I taped them next to the associated section of the foamboard.

Step 2: Gather Necessary Tools

I gathered relevant tools(screwdrivers, wrenches, a locking plier, gloves, carburetor cleaner, safety goggles, etc) before starting the task. 

Step 3: Separate the Carburetors

I removed a bracket and a shaft. The three carburetors were then separated. Subsequently, I rebuilt the carburetors one at a time to avoid confusion.

Step 4: Disassemble the Bottom End of the Carburetor

I took out the float bowl to gain access to the bottom end. I used a locking plier to wiggle the float pin out and removed the float assembly. I then took out the small float valve needle under the float assembly. 

I also took off the starter jet and the screws of pilot jet and main jet.  

Step 5: Disassemble the Top End of the Carburetor

I opened the diaphragm cover to remove the diaphragm spring, needle jet and diaphragm. 

Step 6: Clean the Carburetor With Carburetor Cleaner

I sprayed carburetor cleaner into all the holes of the carburetor. In particular, I thoroughly cleaned the air and fuel inlets of pilot jet, main jet and starter jet. 

Step 7: Assemble the Carburetor

I reversed the disassembly process to assemble each carburetor. Then, I connected all three carburetor back into one unit. Adjustment of the carburetors are recommended in this stage but it is beyond the scope of this document.