1 1/2 HP FBM

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JPar
Posts: 20
Joined: Fri Nov 27, 2015 10:54 pm
Location: Mayoville, MN

Re: 1 1/2 HP FBM

Post by JPar » Thu Feb 25, 2021 8:33 pm

NP317 wrote:
Thu Feb 25, 2021 6:39 pm
"...leaks when engine is cracked..."
What is cracked? The cylinder? The throttle? Clarity please.
RussN
The OP may correct me if I'm wrong, but I believe he meant to write "cranked". As in "spun" or "turned over".
John

Bob D.
Posts: 263
Joined: Thu Jun 21, 2012 10:43 pm
Location: Saco, ME. USA

Re: 1 1/2 HP FBM

Post by Bob D. » Fri Feb 26, 2021 12:05 am

There is nothing problematic with those old Briggs carbs. Super simple and reliable. You say it is rebuilt? Doesn't look like something that was done in recent times, hardware paint/gaskets don't appear to be disturbed. Drop the bowl and clean it. Remove the float and needle. Gently close the main mixture screw to find it's setting (count the turns, typical 1 1/4 turns) and then remove it. Blow some air thru the jet. Put the mixture screw back in and back off to the original setting. Clean the float needle, blow some air thru the needle seat. Put the needle and float back. Float should be level when needle is seated. Easiest to see with the carb upside down. Leave the air cleaner off. No fuel. Turn the engine over with your palm over the carb throat. You should feel good suction. If not you have an engine valve problem.
Is this motor still set up as a make n break? The original fuel mixer (carb) had a poppet valve that isolated it when the engine was spinning over but not firing. I wonder if that is incorporated into the adapter block bolted to the head...
Or has the engine been converted to constant ignition?
Even with gas puking from the carb it should run unless your not getting any vacuum. Hand test will tell you that.
You may have crud keeping an engine valve from seating.
There are plenty of people that mess with these engines. Lots of info out there. Proper mixers are out there too. I don't know your engine displacement but I'm sure it's quite larger than what that Carb is meant for. May well have to have the mixture a bit rich. Generally they were started cold on gasoline, the mixer has a hatch and bowl to fill with gas, then it ran on kerosene.
Whats the backstory on your motor? New to you? Barn find? Sure nice starting with something not found in a field!
It really shouldn't take much tinkering to get it running. Pretty basic and bullet proof.
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3/4" Purinton Mogul "Pogo"
3/4" Hall Class 10 wheeler
3/4" Evans Caribou/Buffalo 2-8-0
3/4" Sweet Violet 0-4-0
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Geochurchi
Posts: 21
Joined: Mon Feb 22, 2021 7:49 am

Re: 1 1/2 HP FBM

Post by Geochurchi » Fri Feb 26, 2021 8:07 am

Hi Bob, others text me the engine did run with the present setup although I have never seen it, I did remove the the carb and rebuild it, I also installed a vacuum gauge onto the intake port to prove there was suction, valves appear to be fine, no poppet valve in block adapter.
I wonder if the fuel tank being higher than the carb is creating a problem, I may try lowering it.
Thanks for the input, it may be awhile before I get back to it.
ALL LIVES MATTER!
Geo 🇺🇸

Bob D.
Posts: 263
Joined: Thu Jun 21, 2012 10:43 pm
Location: Saco, ME. USA

Re: 1 1/2 HP FBM

Post by Bob D. » Fri Feb 26, 2021 12:12 pm

If the fuel tank is less than 3ft above the carb lowering will make no difference. Float level may be to high.
What exactly did you do to rebuild the carb? How did you hook up a vacuum gauge?
Using a squirt oil can filled with gas you should easily be able to keep it running with small squirts into the carb, air filter removed.
3/4" Juliet II 0-4-0
3/4" Purinton Mogul "Pogo"
3/4" Hall Class 10 wheeler
3/4" Evans Caribou/Buffalo 2-8-0
3/4" Sweet Violet 0-4-0
3/4" Hunslet 4-6-0
3/4" Kozo A3. Delayed construction project

1 1/2" A5 Camelback 0-4-0

Geochurchi
Posts: 21
Joined: Mon Feb 22, 2021 7:49 am

Re: 1 1/2 HP FBM

Post by Geochurchi » Fri Feb 26, 2021 1:13 pm

BF1A2799-48E9-42A3-A0D1-D787AEF01D38.jpeg
Hi , for the vacuum gauge I threaded the port of the gauge into a plate that was fitted over the intake port of the engine , in place of the carb. been so long since I rebuilt the carb I can’t remember what I did, I would imagine I purchased a kit, I have been checking my records to see what I can find.
Here is the only pic that I can upload.


ALL LIVES MATTER!
Geo 🇺🇸

Geochurchi
Posts: 21
Joined: Mon Feb 22, 2021 7:49 am

Re: 1 1/2 HP FBM

Post by Geochurchi » Fri Feb 26, 2021 7:40 pm

Hi Bob, just curious if you have ever check this B&S Flo Jet carb out on line, it appears to have a leaking problem with the emulsion tube.
ALL LIVES MATTER!
Geo 🇺🇸

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