Yamaha F40TLRY carb overhaul

[seamanship]

Yamaha carb kit 67C-W0093-02. This kit contains two parts I need help with, 14397-00 o-ring #30 on Yamaha diagram, 14335-00 plunger spring #21 on Yahama diagram.

It seems to replace the o-ring you have to remove part #46 on Yamaha diagram which is a plug. How do you safety remove this plug and can it be reused again? Should I just skip replacement of the o-ring?

Upon disassembly of the carbs mine does not contain a plunger spring. Is this part not necessary?

Yamaha carb #67c-14901-10-00. Actual on carb, Keihin bcm 67C10 NF19.

Would appreciate help with these two items. Have a Seloc book but these two items are not explained.

 

[rodbolt]

Re: Yamaha F40TLRY carb overhaul

#30 should be in the kit, number 21 IS NOT and IF the plunger isnt there it will NEVER run correctly.
however if the carb has EVER had water in it its very likly the plunger is stuck down.
occasinally I can get it unstuck with air pressure, usually it requires a fuel bowl.
like I said, the F40 mercury design is a pain and among the hardest outboard carbs ever produced to make run correctly.
#30 really doesnt do much and the only way to clean that passage is to remove that plug.
it covers the a/f mixture screw.
to remove it carefully drill a 9/64ths hole in the center, use a #10 self tapping screw, insert the screw in the hole, lever it out with needle nose pliers. leave it out or tap it back in, your choice, its there as a tamper proof device as per our wonderful gubbermint.
the same gubbermint that set up the marine stimulous package(E-10).
sounds like maybe the flying monkeys got your carbs already in the past 10 years.
AND the ONLY way to reset everything is by using a 3 channel manometer.

 

[seamanship]

Re: Yamaha F40TLRY carb overhaul

I again soaked the plunger assy. over night with carb cleaner. Took 3/8 wood dowel pin and lightly tapped plunger down to loosen. Turned bowl upside down and banged on wood table and out came the plungers.

On the o-rings #30. The carb plugs do seem a little dumb. I do think I will remove and replace the o-rings. I do not have a manometer. What I plan is to measure from the end of the plug hole to the top of the needles before I remove and then replace the needles to the same distance. After I run awhile I plan to remove the plugs and check color. What do you think?

Thank you for your help. It is much appreciated. We are over 70 and just trying to get a few more years before we hang it up.

 

[rodbolt]

Re: Yamaha F40TLRY carb overhaul

I think your never gonna get it to idle correctly.
its not the A/F screws that bite its resetting the throttle shutters so the engine vacum on each cyl is correct.
however it only takes a few minutes so when your done run it by a yamaha dealer that has a techmate vacummate and have them set the shutters.
most likly when your drill bit breaks through the plug its gonna hit and screw in the mixture screws.
we find something around 3 turns out from ligtly seated works as a good starting point.