Another 1946 Mercury KD-4 Question (Carburetor this time)

[Harrison_Bergeron]

Okay, I added some brand new 105 Lubriplate to the lower unit and got the old KD-4 running for the first time in 10-15 years. It pumps water really well so that was good.

What I am finding is it will run at the start setting and full throttle really well, but the idle adjustment isn’t letting it idle below about the start rpm.

I circled what I think is the idle adjustment needle on the picture below, and I think the needle is just a bit bent so it might not be seating perfectly. Is this most likely the correct diagnosis or am I way off?

If the needle is bent and wont let it idle at lower speeds is there any place like sierra that makes after market carburetor needles?

• This topic was modified 3 years, 8 months ago by Harrison_Bergeron.

[mercuryman]

The needle you show is the Hi Speed adjustment, The idle adjustment should be on right side of carb. There should be a spring under screw needle and set it 1 turn out. I think something wrong where the Idle needle should be I see a regular screw turned in all the way.

• This reply was modified 3 years, 8 months ago by mercuryman.
• This reply was modified 3 years, 8 months ago by mercuryman.

[Harrison_Bergeron]

Thanks! I am a pretty terrible mechanic and I probably put the idle screw back in the wrong spot!

[dave-bernard]

there is a screw next to the welch plug it is the idle tube. make sure it is clean then try to adjust the idle screw. the high speed adj. is fine. bent outside no problem.

• This reply was modified 3 years, 8 months ago by dave-bernard.

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