• Enter the March CB750 Supply gift certificate giveaway! It's easy... Click here, post something, and you're entered into the drawing!

Carburetor Rebuild

Wez_

CB750 Addict
Messages
349
Reaction score
0
Points
16
Location
Enfield, CT
Well, I knew this was going to be a long process. These carbs had about 15 years of varnish sitting inside of them. Finally dove into this "rat's nest"......literally....Honey Bunches o Oats...

20170420_025330.jpg

First thing I did was read the carb overhaul chapter in the service manual. It started the tear down with removing a spring between the 2&3 carbs. After inspecting this method, I concluded that it would be easier to remove the butterflies and separate the carburetors this way. Those springs seem like they would be annoying to reconfigure once removed. Hope this wasn't a big mistake.

Carburetor Before

20170427_001430.jpg20170427_001448.jpg

Just a heads up....Many of the original aluminum screws were so far damaged that I had to take a small flat file and file a "Slit" into the head of the screw and use a flat head screw driver to remove them. This worked very well and all screws were removable. I plan to replace them with stainless hex head hardware.

Started opening up the mess...

20170909_141935.jpg20170909_141949.jpg20170909_142006.jpg20170909_142016.jpg20170909_142537.jpg

These gallon containers of solver are AMAZING....Varnish starting to loosen up...

20170909_142546.jpg20170909_142602.jpg20170909_142735.jpg20170909_142756.jpg

I worked on one bank at a time. Once they were disassembled individually and I felt comfortable with everything including my workspace, I dunked them overnight in the solution, compressed air/carb cleaned them, baking soda blasted them, carb cleaner/compressed air again, solution dunked them, and one last final carb cleaner/compressed air.

Once all 4 carb received this process, my wife was cool enough to let me place all the large pieces in her dish washer. I ran them in the dishwasher on a hot water cycle with NO soap. Then one final carb clean/compressed air.
 
Finished Parts

20170909_182531.jpg20170909_182559.jpg20170909_182619.jpg20170909_182633.jpg20170909_182756.jpg

Found some damage. I was able to JB weld the tube, but there is an inner "furry" o-ring that I think I will have to fabricate...fun...

20170909_182700.jpg20170909_182704.jpg

Had to extract the slow idle speed nozzles out first using a 5/64 drill bit about 2 cm deep, then the extractor did the rest.

20170916_101349.jpg

More pics

20170909_142700.jpg20170909_142833.jpg20170909_182801.jpg20170909_182840.jpg

I have some questions about the rebuild kit I received. When I get those pictures, ill ask the questions. But basically the kit was not a 100% direct replacement. I had to hit up PartsNmore.com
 
This was the best way to organize everything. The ply wood is roughly 3X4'. threw a T shirt over it and sectioned it off with tape. The tape is great for writing notes about each bank

20170916_101408.jpg
 
That is pretty much right as long as you remember the shafts fit in particular locations. I would NEVER mix up the throttle plates if removed or the slides with their tops.
 
Back
Top