70 hp Evinrude water discharge

[mjm91673]

Looking for some insight about the water discharge from a 1984 Evinrude 70 hp 3 cylinder boat motor. Buddy bought a 22' pontoon with this motor and took it out with the families a couple times with 0 problems. 2nd weekend out we had started to have problems at full throttle where it would surge and lack power. Found that the tank was not venting enough, vented the tank and was fine for the rest of the day. Went out the following weekend unloaded it, started and ran for about 30 sec and then would not restart. Reloaded on trailer and took home changed plugs and got to restart. Now it will run fine on the muffs at home but cuts out and sometimes dies at full throttle. Any ideas.

Oh yea and here's the dumbass question. Where exactly is the water discharged from when this motor is in the water? Any boat that I have ever been on before would always have a small stream from just below the seam for the cover. This has two 3/8" size holes but no water comes out.

Thanks for the help.

 

[jtexas]

Re: 70 hp Evinrude water discharge

don't don't don't rev it on muffs any higher than it needs to keep from dying, not more than 2000 rpm - risk of thermal runaway with disastrous consequences.

manual shows a tell-tale on the 1984 70 - outlet on the starboard side of the lower engine cover, hose from the water jacket on the port side. Maybe have got a hole in the hose that fills the cowl with water? Telltale is just to let you know the water pump is pumping. Cooling water exits through the holes just above the propeller. some water will blow out the exhaust relief ports (the holes you described) but only when the engine's in the water.

do a compression test and a spark test, report your results.

and, welcome to iboats!

 

[mjm91673]

Re: 70 hp Evinrude water discharge

Spark test and compression are both ok cylinders are within 5 psi of each other. What are the odds of it having a fuel pump problem or sucking air somewhere thru the fuel lines?

 

[iwombat]

Re: 70 hp Evinrude water discharge

Since you were having problems with the tank vent you likely stressed out your fuel line fittings. May have opened up an air leak someplace. You can test for that with a portable tank and hose. If it works fine on the port-o--tank you found your problem.