84' Evinrude 50hp wont run in water???

[peskate33565]

Just finished refurbishing my 16' flats boat and took it out yesterday to make sure everything was in working order and the motor would not stay idling, I had to throw it into gear for it to stay running. And then the boat wouldn't get onto a plane, the motor lacked a lot of power... Now when I have it on the muffs it runs perfect, nice idle and will rev into high rpms??? I noticed after I got the boat back out of the water the prop wouldn't turn freely, it was in gear but the throttle as in neutral? When I got home I put the muffs on and again everything ran great and the prop was no longer stuck???

Does anyone know what this could be?

 

[Joe Reeves]

Re: 84' Evinrude 50hp wont run in water???

It's really not running fine on the flushette.... just sounds that way.

Start with the basics in trouble shooting.... check the compression, then with the spark plugs removed, check the spark.

Compression should be 100+ psi and even on all cylinders. Spark should jump a 7/16" gap with a strong blue lightning like flame... a real SNAP! Note that the 7/16" gap is important.... checking spark by using the spark plugs is a waste of time.

Let us know what you find.

 

[peskate33565]

Re: 84' Evinrude 50hp wont run in water???

Will the wrong spark plug do something like this?

 

[Joe Reeves]

Re: 84' Evinrude 50hp wont run in water???

Have you run the compression and spark test as above yet?

 

[peskate33565]

Re: 84' Evinrude 50hp wont run in water???

No I haven't had time today, I am going to take it to a near by lake tomorrow (wednesday) to do trouble shooting, how do you check compression without a tool? It does take some force to pump the pistons so I'm guessing it has good compression with just a hand test... In February I had 145 psi for compression according to a mechanic.

 

[Joe Reeves]

Re: 84' Evinrude 50hp wont run in water???

You don't need to have the engine in the water to trouble shoot.

Needed are a 13/16" spark plug wrench or socket, a compression gauge, and a spark tester. Compression gauges are cheap, found at Wal*Mart, K-Mart, Auto Part Stores, just about anywhere. You can build a spark tester as follows.

(Spark Tester - Home Made)
(J. Reeves)

A spark tester can be made with a piece of 1x4 or 1x6, drive a few finishing nails through it, then bend the pointed ends at a right angle. You can then adjust the gap by simply twisting the nail(s). Solder a spark plug wire to one which you can connect to the spark plug boots, and a ground wire of some kind to the other to connect to the powerhead somewhere. Use small alligator clips on the other end of the wires to connect to ground and to the spark plug connector that exists inside of the rubber plug boot.

Using the above, one could easily build a spark tester whereas they could connect 2, 4, 6, or 8 cylinders all at one time. The ground nail being straight up, the others being bent, aimed at the ground nail. A typical 4 cylinder tester follows:


..........X1..........X2

.................X..(grd)

..........X3..........X4

 

[mrcj001]

Re: 84' Evinrude 50hp wont run in water???

Like Joe said, check the compression and spark. It sounds like its not firing on all cylinders.

 

[peskate33565]

Re: 84' Evinrude 50hp wont run in water???

Ok finally the weekend, so here are some details.... I have spark on both plugs, compression is at 150 psi on both cylinders, the bottom spark plug is clean as a whistle no oil or gas. There is fuel in the bottom engine cover, not much, I think it's coming from the bottom carb which I'm guessing explains why the bottom spark plug is so clean??? I usually use muffs when I run the motor but I tried a large tub this time and there was no water coming out of the pee hole but it will come out when in the water or on the muffs? It stalled the first two time in the tub and ran good after that but when I noticed no water from the pee hole I turned the motor off, put the muffs on and it "coughed" and cut off. Started it back up ran for 10 seconds "coughed" and ran fine after that. Also my gas bulb will get soft when the motor is running...

 

[bsandy565656]

Re: 84' Evinrude 50hp wont run in water???

I had the same problem with my 48 h p 1989.evinrude. They will run on one cly. I bet if you pull the plug wire off the bottom it will run for you. Your bottom carb is plugged and not letting gas to the plug. The gas we get today melts the rubber hoses and causes this .(ethenal) Just my thoughts.

 

[peskate33565]

Re: 84' Evinrude 50hp wont run in water???

I had the same problem with my 48 h p 1989.evinrude. They will run on one cly. I bet if you pull the plug wire off the bottom it will run for you. Your bottom carb is plugged and not letting gas to the plug. The gas we get today melts the rubber hoses and causes this .(ethenal) Just my thoughts.

Yes the motor cranks without the bottom wire on... So what does this mean and what do I need to do?

 

[peskate33565]

Re: 84' Evinrude 50hp wont run in water???

Ok, Bottom carb is clean and there was fuel in the bottom, So maybe it's a clogged line?

 

[Joe Reeves]

Re: 84' Evinrude 50hp wont run in water???

Was the inside diameter portion of the high speed jet clean? (located in the bottom center portion of the float chamber).

A really clean spark plug indicates either No Spark or No Fuel.

 

[peskate33565]

Re: 84' Evinrude 50hp wont run in water???

Was the inside diameter portion of the high speed jet clean? (located in the bottom center portion of the float chamber).

A really clean spark plug indicates either No Spark or No Fuel.

Yes I made sure i sprayed into the high speed jet. I believe its getting fuel now I can start the motor with just the bottom plug now... So does that mean the bottom piston wasn't moving the whole time since there was no fuel getting to the spark plug?

 

[bsandy565656]

Re: 84' Evinrude 50hp wont run in water???

Both pistons will move,when the crank shaft turns. Now that your getting gas to both plug maybe you have full power.

 

[peskate33565]

Re: 84' Evinrude 50hp wont run in water???

Ok so I took it out to a near by lake and still the bottom cylinder isn't firing, I had it fire one good time and it dropped. What else could be blocking the fuel flow?

 

[peskate33565]

Re: 84' Evinrude 50hp wont run in water???

Could it be an electric problem? I am getting spark though but maybe when the motor is running it cuts it out?

 

[Joe Reeves]

Re: 84' Evinrude 50hp wont run in water???

(Magneto Capacitance Discharge Coils - Continuity Test))
(J. Reeves)

Check the continuity of the ignition coils. Remove the primary orange wire from whatever it's connected to. It may be connected to a powerpack screw type terminal, a rubber plug connector, or it may simply plug onto a small boss terminal of the coil itself.

Connect the black lead of a ohm meter to the spark plug boot terminal, then with the red ohm meter lead, touch the ground of the coil or the powerhead itself if the coil is still installed.

Then touch (still with the red lead) the orange wire if it's attached to the coil, or if it's not attached, touch the primary stud of the coil. You should get a reading on both touches (contacts). If not, check the spring terminal inside the rubber boots of the spark plug wire. Poor or no continuity of a coil is one reason for s/plug fouling.