Topic: ’54 Fleetwin – wont run on low speed – Antique Outboard Motor Club,Inc

This topic has 44 replies, 15 voices, and was last updated 3 years, 10 months ago by labrador-guy.

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June 14, 2020 at 11:47 am #205685
burnt-clutch
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I recently overhauled my 1954 Fleetwin and I’m trying to run it for the first time. It will only run on high speed. I examined the carburetor and there is nothing plugging either circuit in the carb. I did notice that there is no lead shot in the top of the carb. Would this keep it from running on low speed? Do I have to get the exact OMC part to replace it, or can I substitute a B.B. or something similar from the local auto parts store? Thanks in advance!
-Karl
- This topic was modified 3 years, 10 months ago by burnt-clutch.
June 14, 2020 at 12:16 pm #205690
fleetwin
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US Member - 2 Years
Well, could be just about anything… I take it you have never run this engine, correct? So, you don’t know how it ran before… As for the lead shot, one may or may not belong there, that hole might be a vent…You can try just plugging the hole with your finger just to see if your hunch is correct. Try posting some pictures of the carb and unplugged hole.
In any event, recheck all the basics first. Are you sure it is running on two cylinders? Recheck compression and fuel supply.
I don’t know if you can jam a BB in the hole, I wouldn’t though…There is a specific number for the lead shot: 304201
June 14, 2020 at 1:05 pm #205692
burnt-clutch
Participant
Yes, this a new to me motor I bought awhile back. Compression was 70 and 80 before I put a new head gasket on it. I’ve filed and cleaned the points and have them gapped to .020 at the middle of the “TOP” on the timing cam. I haven’t verified spark on both because my tester died, but I’m assuming that since it does run on the high speed setting both plugs have spark. When I went through the carb this morning I noticed that the slow speed needle has a nick on the end so I guess I need to get a replacement needle as well. Here’s my carb picture.
-K
June 14, 2020 at 1:20 pm #205696
labrador-guy
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US Member - 2 Years
Yup you need a soft plug to put in that big hole! It is the same size as in older snowmobiles. Maybe you have a carb laying around from one of those. Those set of holes control low speed and mid range air/fuel mixture.

dale
June 14, 2020 at 1:28 pm #205697
frankr
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US Member - 1 Year (includes $3 online payment fee)
burnt-clutch wrote:

Yes, this a new to me motor I bought awhile back. Compression was 70 and 80 before I put a new head gasket on it. I’ve filed and cleaned the points and have them gapped to .020 at the middle of the “TOP” on the timing cam. I haven’t verified spark on both because my tester died, but I’m assuming that since it does run on the high speed setting both plugs have spark. When I went through the carb this morning I noticed that the slow speed needle has a nick on the end so I guess I need to get a replacement needle as well. Here’s my carb picture.
-K

“Nick on the end”?? Those needles are famous for breaking the tip off in the hole. If that is what you are saying, it won’t idle till you get that tip out.
June 14, 2020 at 1:47 pm #205706
burnt-clutch
Participant
Thanks for the quick replies. The needle tip hasnt broken off, just has a nick running down it. I found a couple of shots for sale Ebay, I’ll get one and test it again once I get it installed. Are these balls really made of lead? One of the balls that were pictured has some little flat spots on it.

-K
June 14, 2020 at 9:46 pm #205747
labrador-guy
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US Member - 2 Years
What are you talking about? Lead shot? You need a soft plug that fits in the groove right at the top of that cavity. They are a little smaller than a dime. Air and fuel mix together in that cavity on the way to the compression chamber.

dale
June 14, 2020 at 10:29 pm #205748
seakaye12
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US Member - 1 Year (includes $3 online payment fee)
Maybe we’re talking about two different openings? The larger opening shown in your picture needs to be filled with what is typically called a “welch plug” or core plug. They come with the carb kits sold for your engine. They are placed in the opening and then impacted with a punch so as to expand them a bit and hold them in place.

That plug absolutely needs to be there.

OMC carburetors have other openings from the casting process that are sometimes filled with led shots. More often though they are vents and need to be left alone.

Install the welch plug and try getting the idle circuit dialed in; after dealing with the issue with your slow-speed needle. If there are still issues you could try temporarily plugging a smaller opening with your finger or a screw…..see if things improve. My guess would be though that the smaller holes are vents that need to stay open.
June 15, 2020 at 1:31 am #205753
wedgie
Participant
I would double check that it is running on both cylinders. Those motors will seem to run ok (but with little torque) on one cylinder at higher rpm,but will die when throttled back. Get it running and pull the plug wires off (and replace ) one at a time and see what happens. If it stays running (but hitches up a bit,) when either plug is pulled, then it is getting spark on both .If it dies when one or the other plugs is pulled , then the one that causes it to die is the good one..

This test is dependant on the carb being set up close to properly, so you’ll have to sort that first and replace that welch plug etc.
June 15, 2020 at 1:35 am #205754
wedgie
Participant
Having a closer look at the pic of the welch plug, there is some debris in the top right hole. soak the whole carb body in some diluted pinesol and water in a thrift shop crock pot and blow out with compressed air.

Also, you said you filed the points. Try polishing them up real shiny with some very fine sandpaper, then degreasing with acetone, brake cleaner or lacquer thinner.
- This reply was modified 3 years, 10 months ago by wedgie.
- This reply was modified 3 years, 10 months ago by wedgie.
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