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(Backyard Renegade) wrote in message . com...
Well I have an 8 horse Rude, 1988, pull start, great condition, maybe
75 hours on it. Had a problem today, had to keep squeezing the ball
until it leaked to keep it running, but it really did not work. As
soon as I try to idle or now push the choke full off,
snip
Scotty from SmallBoats.com

Hi Scotty,

If there is a little bleed screw on the tank (normally on the filler
cap), it means you probably run an unpressurised system.

With this system, there is no fuel pump. Suction from the running
engine pulls fuel from the carb. Suction from the carb pulls more fuel
from the tank, through the check valves and bulb and into the carb.

The bleed screw on the tank allows air to be drawn into the tank to
replace the petrol drawn out - so if it becomes clogged or is not
open, the tank may be sucked in.

Punmping the bulb primes the system - it draws up fuel from the tank
to fill the hose from the tank to the bulb, the bulb itself, the hose
from the bulb to the carb, and the carb itself. Fuel now doesn't have
to be sucked all the way from the tank before the engine will start,
it's already in the carb bowl.

The check valves make the bulb work
- when the bulb is pressed, the valve below the bulb (nearest the
tank) prevents the fuel from passing back into the tank, so the fuel
is forced instead towards the ob.
- when the bulb is released, the valve above the bulb (nearest the
ob) prevents the fuel being sucked back into the bulb from the ob -
instead more fuel is drawn up from the tank.

If you have, or have access to, another ob that uses the same fuel
connector and tank, try to cut the problem in half.
Run your ob off the known good tank/bulb/hose/check valves - if it
works, problem is in your fuel system.
Test the other combination also.

However, from your description, this sounds like a problem I
experienced last year on our Evninrude 8hp (similar vintage).
Bulb goes hard, engine starts easily enough on choke, run OK on any
choke, dies slowly after choke is cut.
Couldn't fix it ourselves - dealer took apart carb and fixed.
There are apparently two relevant passages for fuel through the carb.
The low speed one had clogged.
With even a little choke, enough fuel got through that way to sustain
the engine. As soon as choke was fully closed, engine died.
There is also a high speed passage, so the engine might run under
higher throttle, if you can get it there.
He found a blockage in the load speed passage - when cleared, problem
solved.

This explanation is based on my understanding of what I thunk the
dealer said, and may have gotten a bit confubulated in me noggin.

Problem was probably entirely due to user stupidity - after the last
run of the season, I ran the engine in a bin of fresh water to flush.
Forgot to run the last of the fuel out of the engine before switching
off, and only remembered half way home (4 hours away).
Swore I'd do it on the next trip, wrote reminders several places that
I couldn't miss, forgot completely.
Petrol in the carb probably varnished up the passage over the winter.

By all means clean the filter, check the bulb, hose and tank - these
are easily checked and eliminated, but it sounds close enough to the
problem I had...

You could a can of carb cleaner, but if the passageway is completely
blocked, it might not work.

When was the last time the engine ran?

Regards,

bookieb

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