1978 115 hp evinrude top end issue

[CarolinaCatDaddy]

The problem im having is the boat will run great in the yard. The only slight issue is when going from idle to in gear its misses for a second but then runs great. Soon as you put it in the water and try to go wot it just boggs down. Feels like it runnimg on one cylinder. Took the carbs off. Gaskets are still in good shape. There was some build up there. Not much. Clean them and put them back on. No change. There was one fuel line leaking a little so i changed them all. We checked the compression and all 4 cylinders were ok. Checked the coils and found that 3 were bad. Thought for sure that was the problem. Put 4 new ones on and still no difference. Ive been reading thread after thread trying to figure out what i should check next. Any information would be greatly appreciated

 

[CarolinaCatDaddy]

New plugs and wires as well

 

[racerone]

It just sounds " great to you " in your yard and it means nothing.-----Post your actual compression numbers.-------Does spark jump a gap of 7/16" on each lead ?-----Checked the flywheel key ?---Fuel pump diaphragm checked.------How did it run for you a month ago ?----Are wires from powerpack going to the correct coil ?

 

[CarolinaCatDaddy]

They were all between 100 -110. I didn't write them down because they were all within 10% of each other. Ive had this motor for 5 years. When i got it i had this issue and then times got hard so motor sat in my yard. I can check the jump of the plugs. Yes the wires are correct. What would i be looking for on the flywell key? Ill look up how to check the fuel pump diaphragm. And ill mention its got a brand new tank, new fuel line and primer bulb

 

[racerone]

The spark plugs were not mentioned when I suggested checking the maximum ignition output.---Use a spark testing device.---Fact---- a sheared flywheel key throws out the timing.----Perhaps remove bypass covers to inspect pistons and rings on the 40 year old motor.

 

[CarolinaCatDaddy]

Ill go pick up a spark tester tomorrow. We plan to pull the flywheel head monday. Wanted to check the condition of the stator and magnets. I will check for a sheard key

 

[CarolinaCatDaddy]

Ill check the fuel pump tomorrow. Seen a thread on un mounting it then putting a nut on the back side,tightening it back together, pumping the bulb , and looking for leaks. Anything else i should look for on it

 

[racerone]

I think it would be easy to figure out what is wrong.----Time to do some real trouble shooting.

 

[CarolinaCatDaddy]

You aint got to be a db.