View Single Post
  #12   Report Post  
Brian D
 
Posts: n/a
Default 88 Evenrude, won't stay running?

How big?

Brian

--
http://www.advantagecomposites.com/tongass -- My 22' Tolman Skiff project
http://www.advantagecomposites.com/catalog -- Discounted System Three
Resins products


..
"Backyard Renegade" wrote in message
om...
(Backyard Renegade) wrote in message

. com...
(Backyard Renegade) wrote in message
. com...
(Backyard Renegade) wrote in message
. com...
"Steve Lusardi" wrote in message

...
I suggest the fault is the tank, not the motor. The tank is

leaking air. The
squeeze ball charges the tank. The overpressure tank then feeds

fuel to the
carb. Check your seals, gaskets, hose and hose fittings.
Steve

This confuses me. I have always kept the air valve open on top of

the
fill cap for the tank, the pressure is equal to that outside the

tank.
The ball has checks in which allow me to build up some kind of
pressure in the engine, I have always assumed that once the engine
starts, it somehow draws fuel from the tank, in line with the check
valves. This could only happen if the engine were somehow sucking

fuel
from the tank. In fact when I leave the fill cap vent closed, it

sucks
the tank down (red plastic portable tank).

Anyway, I have had a better look this morning and I see that the

valve
I refered to below does not have an electrical lead, it is more

likely
a vacume lead, maybe some kind of vacume actuated idle control (idle
air bypass)? The choke knob feed directly into this unit which also
has two fuel lines running to the carb, one low, one high, could

this
also control idle fuel?

Anyway, to the fuel pump, can someone explain how it works on this
engine, that will help me to find it! Is it vacume, or mechanical,

in
the meantime I will be looking today in better light, thanks again,
Scotty, Keep em' coming...



Nevermind... I found the fuel pump. It's that thing with springs,
valves, and diaphrams that sproings apart when you remove the wrong
two screws Everyone carries this pump, well except this year, called
7 dealers, all out of stock till the end of vacation week, ****.
Anyway, looking at the pump it seems pretty simple, there is an airway
that I imagine leads to the intake, so I guess the diaphram is run by
fluctuations in the intake vacume, makes perfect sense to me. Anyway,
hopefully this is indeed the problem, I can't see anything else right
off hand that would create a fuel or vacume leak anywhere else on the
engine.
Now off to see why the heck the one year old water pump on the 3 horse
merc stopped working... I hate this stuff, I just want to build boats
and go fishin'. Scotty



Well, anyone? Am I right about the intake pressure fluctuations
driving the pump? Looks like it. There is a flame arrest plate in
front of the diapharam, this pretty much confirms my suspicions
especially since it was clean, no backfires. I know they would not
drive the fuel pump with exaust. Anyway, I get the pump on friday, I
will let you know.



Well, it did not work, the fuel pump and plug wires too, cause it
makes sense since I had new plugs and all. Anyway, I am thinking it is
carb now after setting all the other perams'. Anyway, I will keep you
posted even more... Building a big skiff now, I will post some pics
soon.

Scotty