Wisconsin RBM starting help

[Buccaneer]

This video is from two years ago after went thru my Wisconsin M.
I failed to get it going with a Bendix gear driven magneto, and I
made a homemade timer to use via battery ignition.
I did make “smoke”, but never got it started.

The timer had a timing advance, and I tried various settings.
I’m “fuzzy” on how to start a motor by bouncing it off
compression, and where the plug should fire relative to TDC
when doing so.
Any thoughts or theory on this appreciated.

The motor seems to have plenty of compression, and is hard to
pull thru compression to try to start it that way.

I just went thru the timer today, and found nothing wrong
with in, in theory anyway.

Any thoughts before I try starting it again?

the coupling halves between the drive and driven sides,
are pinned rigid, but I was shown by Geogre Emmanuel’s
photos that his coupling was designed with lots of slop
in it, and I believe his theory was it was to aid in
priming the engine while bouncing the motor off of compression.
Not sure if I need to design slop in my coupling or not.

Any ideas on theory or actual practice on starting RBM’s
of this type, appreciated!

I almost get sea sick watching my video, so sorry for that.
Next time it will be mounted solid and out of water!
Thanks.

https://youtu.be/cLPNsNn5S4o

Prepare to be boarded!

[Bob Wight]

Buc – I remember when you were restoring this motor a couple years ago. I don’t have a clue about how to get it started, but just wanted to say it sure turned out to be one fine looking motor! I’m sure one of the RBM experts will help you get it running!

Bob

1937 Champion D2C Deluxe Lite Twin
1954 Johnson CD-11
1955 Johnson QD-16
1957 Evinrude Fastwin 18
1957 Evinrude 3022
1958 Johnson QD-19
1958 Johnson FD-12
1959 Johnson QD-20

“Every 20 minute job is only a broken bolt away from a 3-day project.”
"Every time you remove a broken or seized bolt an angel gets his wings."

[Tubs]

The ooze coming from the exhaust would
seem to indicate to much fuel. When a motor
wont start take out the plug an check to see if
it is wet. If it is shake out the fuel or better yet
blow it dry with air. Spin the motor over a
dozen times or more with the plug out. Then
put the plug back in and with the mixture screw
closed all the way try to start the motor so it
can clean itself out. To start a motor by
bouncing it off compression you need to have
the spark plug firing after TDC. As you spin the
motor backwards the plug fires before the piston
reaches TDC causing the motor to reverse
direction and take off going forward. When your
spinning it backwards the point where your
releasing the knob is the point where you want
the plug to fire.
Tubs

A "Boathouse Repair" is one that done without having tools or the skills to do it properly.

• This reply was modified 3 years, 11 months ago by Tubs.
• This reply was modified 3 years, 11 months ago by Tubs.
• This reply was modified 3 years, 11 months ago by Tubs.
• This reply was modified 3 years, 11 months ago by seakaye12.

[Tubs]

The ooze coming from the exhaust would
seem to indicate to much fuel. When a motor
wont start take out the plug an check to see if
it is wet. If it is shake out the fuel or better yet
blow it dry with air. Spin the motor over a
dozen times or more with the plug out. Then
put the plug back in and with the mixture screw
closed all the way try to start the motor so it
can clean itself out. To start a motor by bouncing
it off compression you need to have the spark plug
firing after TDC. As you spin the motor
backwards the plug fires before the piston reaches
TDC causing the motor to reverse direction and
take off going forward. When your spinning it
backwards the point that you releasing the knob
is where you want the plug to fire.
Tubs

A "Boathouse Repair" is one that done without having tools or the skills to do it properly.

[Buccaneer]

Tubs, I have two notifications that you posted replies, but I don’t see them.
Your thoughts are always appreciated, Thanks.

Prepare to be boarded!

[Tubs]

Working Today?

A "Boathouse Repair" is one that done without having tools or the skills to do it properly.

• This reply was modified 3 years, 11 months ago by Tubs.

[Buccaneer]

I see your post Tubs if that’s what you mean.
If you mean “me”, yes also, on the laundry dryer,
Elto Ace carb, the Wisconsin outboard, and
the faux fireplace I’m making for the wife, lol.

Prepare to be boarded!

[Buccaneer]

I did some experimentation today to see
what “range” my Wisconsin timer has
on it’s spark advance mechanism.

To start it via bouncing if off compression
in reverse rotation, with the timer fully retarded,
the furtherst it will fire from piston TDC is 1.350,
or close to 1-3/8″.

With the timer fully advanced, in forward rotation
of the engine, it will fire .190 BTDC, or about
3/16″.

If the engine is started in a reverse bounce with
the timer fully retarded, it will be running
and hence “firing” about .685 ATDC, until one
can advance the timer.

I’m not smart enough to translate inches of piston
travel in relationship to degrees to TDC. I do
know the piston has a stroke of 2-1/2″.
I suppose one could make a degree wheel to tape
on the flywheel, but I don’t know what specs I’d
be looking for anyway.

The place I’d want it to fire via bouncing off compression
is a little hard to exactly calculate, but guessing
my timer has enough range to start the motor in that manner.

Prepare to be boarded!

[Tubs]

Don’t turn it into brain surgery. You just need
to get the plug firing at the point where your
letting go of the knob which is the point the
piston stops moving upward. Getting the
right fuel mixture so it will take off is trial
and error. Mostly error.
(Lead burn off to the heat element on the dryer ?)
Tubs

A "Boathouse Repair" is one that done without having tools or the skills to do it properly.

• This reply was modified 3 years, 11 months ago by Tubs.

[RICHARD A. WHITE]

If you think it is flooded, simply shut the fuel off, then keep rolling it backwards, she will fire once enough is gone, then quickly open the fuel valve….
the range varies, But once you get to half turn out it should fire again, if it even dies… I have one that will run at 1/2 turn out from gently seated, others require more than one turn out from gently seated. It all depends on the motor.

http://www.richardsoutboardtools.com
classicomctools@gmail.com

[Author]

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