Continuing with part two, we will be disassembling the carbs from the air silencer and manifold brackets, and begin the disassembly of the carbs for inspection and cleaning. First Id like to know where the pilot screws are before touching anything so each of them are drawn into soft seat and the values are recorded. All were found within spec. After this, all bowl drains are removed for a pre-inspection of the back of the bolts for rot of any kind and none was found.
With the preliminary work out of the way, the accelerator pump is removed where it is immediately found that an inappropriately shortened air line has cracked causing an air leak in this system. This will be repaired later. After this the silencer is removed, working the bolts from the middle outward to break tension. With the bolts gone the silencer and brackets are put off to the side and washed leaving the four carbs behind connected by fuel lines.
The carb fuel lines are in two groups, the fuel from the pumps and from the cold start valves. Cable ties hold them together and are removed to separate. It is noticed a brass fitting is broken in carb 4 requiring repairs. With the hoses separated, all four carbs are now separate. The project will start at carb found (bottom) and work up to one (top).
First I took a minute to try to remove the broken brass fitting from the the hose on carb 3. Someone glued it in, and I ended up cutting the hose to remove it. Carb four will Now be completely disassembled. This carb has no cold start valve. No major contamination was found in this carb, everything was cleaned with brake cleaner and blown out with compressed air. I was not happy with the carb rebuild kits I had. The recommended OEM and if desired, a NON-OEM kits are shown below.
YAMAHA CARBURETOR REPAIR KIT MERCURY 40 45 50 HP 4 STROKE 62Y-W0093-11-00
amzn.to/3mhxuOH
NON OEM version
amzn.to/41i3vVL
J-B Weld 8265S Original Cold-Weld Steel Reinforced Epoxy
amzn.to/41euMbr
With my kit I opted for using the existing OE parts in the carb if they were still good, effectively using the new seals and float bowl needle only. If I had the OE I would have swapped everything.
The Float of the Chinese kit against the old OE was measured. The old OE was 10mm which was correct. The new one was way off. The old float was reused. The carb and brass piece is prepped for repair.
CARB DATA COLLECTED
Carb 4: 2 Turns - 114/39, float 10mm
Carb 4 is then reassembled and inspected, put back in line and carb 3 is pulled next, though ill need to get some JBweld...
Onto the rest of the carbs......
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