83 Evinrude 60 - Strange starting

[ruffneck2]

I have a 83 Evinrude 60 that I just cannot get to work here is what I am done

-Cleaned carbs (jets, drains, floats work) they are all clean
-Changed fuel filter (new gaskets)
-Changed fouled plugs (thought it kept fouling them but I am not sure anymore)
-Checked compression all good minor difference between cylinders but still strong

Here is what happens and I just cannot figure it out

Fuel primed into empty carbs, fresh fuel, start motor chocked fast start on. The motor will start for about 5 seconds, rough idle then it will quit, start it again and sometimes you can rev it up but it will just QUIT like hard quit just stop and backfire, sometimes it will have a decent idle then give it gas and it starts to rev then quits. It pointed to fouled plugs but after multiple times cleaning them and or new ones I am at a loss. It almost seems like the timing is off, could it be the CDI box?

Any help would be great! This motor has never treated me bad and I have taken awesome care of it, it just started doing this year. I cant imagine it being a piston ring since it does idle?

Thanks in advance!

( I can post a short video of what its doing if that helps anyone, I have had my mechanic friend who builds hotrods for a living and he is stumped too)

 

[Monte1961]

Re: 83 Evinrude 60 - Strange starting

try squeezing the primer bulb to see if it will stay running. also pull fuel line of between fuel pump and carb/s, turn engine over to see if it pulses fuel. post back results!

 

[ruffneck2]

Re: 83 Evinrude 60 - Strange starting

It should pulse while the boat is trying to start correct?

 

[Daviet]

Re: 83 Evinrude 60 - Strange starting

Correct, the pump operates off of a pulse created by a piston moving back and forth. What plugs are you running?

 

[ruffneck2]

Re: 83 Evinrude 60 - Strange starting

The pump is pulsing fuel, NGK B7HS10. It revs up with starting fluid just fine

 

[Will Bark]

Re: 83 Evinrude 60 - Strange starting

You MAY want to change to Champion plugs You MUST quit using starting fluid which has no lubricant and will ruin your engine; use a squirt bottle of premix fuel instead.

 

[ruffneck2]

Re: 83 Evinrude 60 - Strange starting

The starting fluid was only for a very short time to see if it was a fuel/spark problem now be it it ran on starting fluid pretty well, I am just back to square one here

-Fuel pump pluses fluid
-spark plugs new (work on SF) will be changing to the OG Champion plugs
-carbs have fuel in them opened drain to see

it still will start for a very short time, very rough then backfire and quit, but it wont do this on starting fluid! I am desperate here, its hot out!

Thanks!

 

[Monte1961]

Re: 83 Evinrude 60 - Strange starting

use a spray bottle and fog the carb/s. will it stay running? 50:1 fuel mix.

 

[Daviet]

Re: 83 Evinrude 60 - Strange starting

Just because there is fuel in the carbs it does not mean that the fuel is reaching the engine.
When you overhauled the carbs did you remove the core plug on top of the carbs and clean the tiny passages in there? Did you remove both the idle orifices and make sure they were clean?
As Monte1961 suggested, squirt some fuel mixture into the carbs and see if it will run, if so, you have carb problems.