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First start on this motor since I got it. I did not tear into the power head,
but did install new o-rings in the carbon seals, and went through all
the other components on the motor.
The RD owner’s manual say initial carb adjustments…..
High Speed 1/3 turn open
Low Speed 1-1/4 turn openI got the motor to fire right away, but had a "lean sneeze"
and wouldn’t run more than a couple of seconds.
I tried different carb adjustments, etc.
My mercury switch had the wire "off" when I got it.
I band-aided a new wire to it, but even when
testing on the bench with the VOM it was "iffy".
I thought I had the mercury switch adjusted on the motor
using the VOM so the switch would be "closed" when the throttle was in the
"start" position. In real life, the switch would open just before
the throttle would start to open, not allowing me to crank the engine.
I by-passed the mercury switch, got the throttle to open a little, and got it started long enough
to take a short video. Didn’t realize until later that I had the
choke half on the whole time.
I tried restarting it a couple hours later, and could not keep
it running, and it kept lean sneezing / farting! Tried different
carb adjustments, choke settings, etc.Perhaps if I had it on a boat and could get it running, tunning
would be much easier! Alas, my little AL Alumacraft said "No Way"
to that thought.
In the mean time, until I find a boat big enough for a 25 hp to
beg, borrow or steal, any suggestions? I’d like to know if it’s
just the carb settings or something more ominous, before it
hits the lake, and know that it will actually start when it gets there!
P.S.- Is finding a 60 year old replacement mercury switch still the
best option to replace the old one?
The video…….
https://youtu.be/bO8_g74k_B0
Thanks !Prepare to be boarded!
1 user thanked author for this post.
Ben, it was June 28th when I had the carb apart. No photographic evidence of
the boss gasket, but pretty sure I made a new leather one, or borrowed one
from an open carb kit.
Interesting enough, I just looked at the carb diagram, and I can’t for the life
of me see a "boss gasket".
Did they not put them on some model carbs? Could I have an issue installing
a boss gasket if there isn’t suppose to be one?
Refresh my memory please…….. Is the carb’s low speed circuit fed
through (and shared with the high speed circuit) the center nozzle,
or through a passage in the carb bowl?
Thanks for the help!quote Fisherman6:It seems that my RDE-16 has the high speed needle open closer to 1/2 turn or a little more. Do you kniw if your carb has the boss gasket in it or not? It could be that the 1/3 turn could be the setting without a boss gasket and your carb has one in place? I don’t know. I have been into only 2 of these carbs. Neither of those had a boss gasket when I took them apart, but I put one back into both of them. With that gasket in the carb, both of the carbs are between 1/2 & 3/4 turn out for best running. Not having it in there certainly allows more fuel into the high speed circuit at the same needle setting.
-Ben
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Prepare to be boarded!
Buc, here’s a pic of the gasket Ben is talking about. #59 in this catalog for a 1958 FD-12 (18hp). Hope you can make it out.
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Top is a NOS gasket for jw-fd models. All the previous numbers superseded to #344037. It has square edges.
Bottom is the one I got from mcmaster-carr. "70 BUNA size 201"
Will gladly mail a few to whoever may need some. I have about 92 left! 😆
Scott
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