78 70 HP EVINRUDE SET UP

[MESS147415]

Hi everyone, finally got my manual and have tried to set up engine to the book - i have good spark, good compression - 130psi on all 3. engine is now useable and weve had a couple of fun days out but i still have a couple of things i would like advice on: 1. to get the unit to idle at a reasonable speed i have to set static timing to about 5 btdc - book states 0 - will this give me a prob long term - idle jets are fixed. 2. if i let the boat stand or idle for a while, it is reluctant initially to rev above about 2000 rpm - opening the throttle further will cause the engine to die. with a little patience she will eventually open up and run perfectly - any idead please guys? steve

 

[Joe Reeves]

Re: 78 70 HP EVINRUDE SET UP

If priming the fuel primer bulb causes that problem to vanish, I'd suspect a fuel/air leak between the fuel pump and the fuel supply. If no leak is evident and the problem still vanishes, I'd suspect a failing fuel pump.<br /><br />If the above pumping of the fuel primer bulb has no effect, I'd suspect carburetor problems, in which case, clean them..... or the timer base under the flywheel may be sticking intermitently.<br /><br />I'm assuming that you do have the carburetor cam adjusted so that the throttle just starts to open as the scribe mark on the cam is centered with the roller.

 

[MESS147415]

Re: 78 70 HP EVINRUDE SET UP

Hi Joe, the primer bulb is fairly solid under all conditions, i have tried blipping the choke - this momentarily cuts the engine totally then she picks up and away we go again!. I have cleaned the carbs.I have had great probs getting the engine to run satisfactorily and it all seems to be related to the throttle/ timing setting, now i have set it to the manual with the exception of the timing at pick up which i have had to set at 5btdc to get 800rpm when in gear at tickover - could it be that i am too advanced now at low revs? steve

 

[MESS147415]

Re: 78 70 HP EVINRUDE SET UP

is there any other way to set tickover other than timing? carbs are fixed jet steve