1948 Scottie Carb

[coolness]

I pulled the carb off the '48 Scottie and cleaned it. Question - The screw on the very top of the carb - is that an adjustment screw? It was turned in all the way. And the screw with the spring on the front, the idle screw? Any other adjustments? Thanks!!

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[tmcalavy]

Re: 1948 Scottie Carb

The little screw on top is a plug to seal the idle circuit...should be in tight. Only time to remove it is when you are cleaning the carb. The top/front screw with spring behind it is the idle circuit adjustment needle. Immediately below the carb throat is the high-speed jet adjustment, with the center knob on it. Very simple carb...if you're going to clean it, start with a clean workbench and some newspaper spread out on the bench...lay the pieces out logically as you disassemble it, or take some digital photos as you go along so you can get everything back right.

 

[coolness]

Re: 1948 Scottie Carb

Thanks tm. I did not take the carb completely apart. I did remove a couple screws, namely one on the bottom and the idle circuit screw. I sprayed carb cleaner into the carb (also through the gas on/off opening) and shook it to slosh it around. I did this 4 or 5 times and the cleaner was fairly clean the last 2 times. The first few "drainings" were pretty dirty. Should I diassemble the carb? Don't want to ruin the gasket..... I do know it ran pretty good before any cleaning.

I did remove the idle screw and cleaned that port as well as the rest of the exterior.

 

[F_R]

Re: 1948 Scottie Carb

Odd thing about the idle mixture adjustment on those carburetors---it works "backwards" Screwing it in makes it richer, out makes it leaner. That is because it controls the air in the mixture. Normal opening is 3/4 turn or less. Most carburetors control the fuel in the mixture.

 

[1946Zephyr]

Re: 1948 Scottie Carb

Yes, that's exactly right. These looked very similar to the older Johny/Rude carbs in design, but the low speed works the total opposite. It's an air bypass type setting, versus a fuel flow setting. Evinrude actually used Tillotson carbs on a couple models, before 1954, namely the older 14hp Fastwin. Scotts and West Bends used a lot of these carbs.
That little hole you see above the low speed needle is the air hole, for the air mixture. You want to make sure that is perfectly clean inside. From the looks of your carb, it looks to be in nice shape. I've ran a lot that were no where near that nice. There may not be a need to tear into it, if you can get it clean from flushing it out. There should be a little drain screw on the bottom of it too.

 

[coolness]

Re: 1948 Scottie Carb

Thanks Zeph!! Yes, the carb is in pretty good shape being 62 years old.

I did find that drain hole on the bottom, removed the screw and flushed through it. It was amazing how dirty the first few flushings were. They were quite clean after that. I don't think the carb was abused except for the loss of the control knob inserts. Wonder where I can find those??

I can't wait to get it running again.

 

[1946Zephyr]

Re: 1948 Scottie Carb

Like I said before. Join up with the AOMCI and there is at least a couple guys there who would be willing to help you out with parts for that classic of yours. www.aomci.org You can also post a want ad there and the mice will come out of the woodwork. Your model was one of the more common models