'88 140hp V4 - strugglin to idle

[mc8]

Been browsing around on here for the last couple of days to see if I can get this figured out, here's my issue

Got a pair that came with a boat. They have been sitting for ~2 years. Got one started and running smoothly by flushing the carbs out and with a new fuel filter idles perfectly. Currently have them hooked up to a small clean 3 gal fuel tank with a proper mix

The second one is giving me a bit of trouble. A new starter solenoid got it cranking. The fuel pump was spraying fuel from a missing O-ring, wonder where it went, got that replaced, it started and idled after that for a bit. But after idling for bout 30-60 seconds it either
A) Sputters, farts a puff of white smoke and/or dies slowly (got the lower unit in a water tank) or
B) the revs start climbing and stop and then A would occur

I noticed that after shut down, one of the carbs was leaking fuel, opening the throttle plate with the engine off it pours out a good bit. Facing the carbs it's the top left or the top starboard carb. Took the carb apart and it looked clean, did the "blow test" on the float needle and it sealed right.
Swapped a carb over form the good engine, same result.
Swapped a fuel pump from the good engine, also same result.

Thinkin the electric choke may be a defective too, takes a long time to get it started cranking but if I manually flip the tab open/close before hand, fires right up and proceeds to do the above mentioned.

Thanks for any suggestions

 

[Daviet]

Re: '88 140hp V4 - strugglin to idle

Start with some basic checks, compression and spark. If those check out ok, you are probably going to check the fuel delivery system and maybe overhaul the carbs.

 

[ezeke]

Re: '88 140hp V4 - strugglin to idle

If the primer solenoid valve is not working correctly you can repair and upgrade to a schrader valve with the parts from your BRP/Evinrude dealer.

You will need Kit #0437228 and # 0175158- About $20.

The primer solenoid should be operated by pushing in the key if the wiring is good; the red handle should be aligned with and adjacent to the cylindrical base of the solenoid for all normal operation.

It sounds as though you may have something caught in a reed if you are getting a steady overflow of fuel from only one carburetor (although you will definitely flood if you leave the primer solenoid valve open).

 

[jtexas]

Re: '88 140hp V4 - strugglin to idle

fuel comes out the carb throat while the engine's not running, you just need to install carb kits. Probably the float valve, but there's a number of gaskets & o-rings in there to get stiff with 2 yrs of non-use, no use trying to pinpoint the leak. They all need replacing anyway.

 

[mc8]

Re: '88 140hp V4 - strugglin to idle

I thought that but, I swapped good carbs from the second motor into the place of the leaking one, and the leak persisted.
Can't be that a carb doesn't leak on one side of the motor and leaks on the other due to internals of the carb I would think.
Haven't had the time to work on them in awhile till yesterday.