1988 -70 hp runs great until in water :( HELP!

[Phoenixfirewalker]

I have a 1988 evinrude 70 hp which runs great in my garage but seems has become afraid of water .

Ilaunch my boat, I prime, I start, I warm (so far so good) I go from the no wake zone out of the beach and it gets lazy until it stalls. afterwards doesnt
want to start until I give it the forbiden fumes of the starting fluid.

what do i do now?
gas hose and filter are new
plugs are also new

 

[R.Johnson]

Re: 1988 -70 hp runs great until in water HELP!

At this point we know the engine will run. I would do a compression check, if OK, I would do a pressure, vacuam test on the fuel system.

 

[Phoenixfirewalker]

Re: 1988 -70 hp runs great until in water HELP!

will check up on that fuel pressure.

it is as if drowned in fuel

 

[Phoenixfirewalker]

Re: 1988 -70 hp runs great until in water HELP!

please help!!!
that it?

 

[poorboy123]

Re: 1988 -70 hp runs great until in water HELP!

from my expierince if fuel pump is bad it will still run good on the hose pipe. when you put it under a load or accelerate it starts to stumble.

 

[Phoenixfirewalker]

Re: 1988 -70 hp runs great until in water HELP!

hum....
will check up on that
any more advice?

 

[jtexas]

Re: 1988 -70 hp runs great until in water HELP!

Did you replace the primer bulb and fittings with the fuel line?
Can you make it run better by pumping the primer bulb while trying to accelerate?
Is the fuel line still pressurized when it dies?
Is the gas fresh?
Is the tank free from water and debris?
When was your last carb rebuild?
What's the compression on this motor?
Does the timer base move smoothly to its stop without sticking when you advance the throttle?


Take the air silencer cover off, tilt the motor full up (not running), and squeeze the primer bulb. If gas runs out the carb throats, your float valves are worn or misadjusted.

 

[Phoenixfirewalker]

Re: 1988 -70 hp runs great until in water HELP!

I still am having those problems I mentioned and the carbs are full of oil. remember that the VRO is disconected and that gas is mixed with oil in the fuel tank

primer bulb and gas line new
fuel filter and gas line new
a little line (like vacum hose) leaks some gas when primed

will check on the floats and compresion . will post i a few hours
thanks a lot. I need to sell this boat. it was great ntil decided to sell

 

[jtexas]

Re: 1988 -70 hp runs great until in water HELP!

the only vacuum line I know of on that motor is the pulse line between the manifold and fuel pump -- a leak in that line will weaken the fuel pump....but if gas is in there, it means the diaphram is perforated and leaking into crankcase, flooding you out and causing your symptoms.

 

[Phoenixfirewalker]

Re: 1988 -70 hp runs great until in water HELP!

great!
how do I fix?
rebuild fuel pump?

 

[Phoenixfirewalker]

Re: 1988 -70 hp runs great until in water HELP!

compression
top cyl 115
mid cyl 70
bott cyl 130

not leaking from the vacum , my bad. it was leaking from a vacum size little tubbing going to the carbs. changed the plastic t and put new ties. not leaking now. I dismantled the fuel pump (my first) the membrane was not broken but quite worn in.

I think maybe im not getting gas upthere anymore. only starts when I spray gas or starting fluid.

should I still rebuild the fuel pump?
what should I do
Im selling it and have little money to spend

 

[jtexas]

Re: 1988 -70 hp runs great until in water HELP!

sorry to say, without good compression on all 3 cylinders, the motor just isn't going to run no matter what. Only thing you can do is pull the cylinder head to see what happened.

 

[Phoenixfirewalker]

Re: 1988 -70 hp runs great until in water HELP!

yep!
gotcha
will take to the tech monday