1977 evinrude/johnson 115hp ignition trouble

[phoneguy925]

ok picked this engine up about a year ago it had no spark and good compresion. so through searching around i put a NOS wiring harnis inside the engine and outside to the controles plus 4 new coils new CDI pack , new timing base and a used stator off a running engine that blew a cylander. using the manual and the steavens s80 test set and steavens spark gap tester i now can get all 4 coils to put out good spark when no plugs are in the engine but what ever cylander i close off with either a plug or a cap i loose the spart on that related coil. was hoping some one may have an idea because im stumped. everything acording to the manualy seems to test good now.

 

[emdsapmgr]

Re: 1977 evinrude/johnson 115hp ignition trouble

Double check to be sure you loose spark. Get an inductive timing light. Put the main lead on each of the 4 plug wires and check for flashes with the light when cranking the engine. You should see, strong, constant flashes from each wire. You also may have spark jumping to ground-which you can see if you crank at night in the dark.

 

[tashasdaddy]

Re: 1977 evinrude/johnson 115hp ignition trouble

agree. are you using Champion Plugs OL77JC4 gapped at .030?

 

[phoneguy925]

Re: 1977 evinrude/johnson 115hp ignition trouble

i am definately loosing spark it happens as soon as any cylender is under load and only that coil drops. im thinking im loosing spark when compresion is built up and the rpm's slow down from the starter. but dont know why this is happening. i have checked all the normal stuff such as all ground straps wiring and any posible arking i even dipped coils in rubber dip to make sure no arking.

 

[phoneguy925]

Re: 1977 evinrude/johnson 115hp ignition trouble

tashasdaddy, the plugs and gap im using is not relavent as im not using the plugs to test for spark. i am using a meater and spark tester as well as my own hand. but i did try your idea emdsapmgr theres no couil output when the cylander is closed up.

 

[ezeke]

Re: 1977 evinrude/johnson 115hp ignition trouble

It is happening because you are not turning fast enough when you have any load on the engine. You need 300 RPM to make that system fire. You are obviously able to reach that with no plugs in place.

If the battery is large and fully charged, the next thing would be to replace the battery cables. Or, you could check the starter circuits with voltage drop tests.

 

[phoneguy925]

Re: 1977 evinrude/johnson 115hp ignition trouble

ezeke, ok thanks for the info about needing 300pms to fire. i did replace the starte solinoid because it fried do you think replacing the starter it self will help or sould i test the starter it self and if so how would i test it.

 

[ezeke]

Re: 1977 evinrude/johnson 115hp ignition trouble

Battery cables and load test the battery at a battery dealer - even a new battery can be faulty. My guess is that your cables look fine but are junk inside the sheathing.

 

[phoneguy925]

Re: 1977 evinrude/johnson 115hp ignition trouble

i will check the bateries and the cables, but cables are brand new i just made them up 2 weeks ago all solder ends used 4 gage tinned stranded bater cable and heavy dutey tinned terminals with high temp solder all heat shrunk and im using 3 heavy duety marien bateries in paralel they are the same bateries i use to start my other boat.

 

[ezeke]

Re: 1977 evinrude/johnson 115hp ignition trouble

See if there is an automotive starter rebuild shop near you. They can check and rebuild a starter for half the cost of new.

 

[phoneguy925]

Re: 1977 evinrude/johnson 115hp ignition trouble

so you think it could be a week started then?

 

[ezeke]

Re: 1977 evinrude/johnson 115hp ignition trouble

If you do the voltage drop test in your manual, you can usually isolate the weak point in the starter circuit.

 

[phoneguy925]

Re: 1977 evinrude/johnson 115hp ignition trouble

ok i will do that after work today i will poast back with results.

 

[emdsapmgr]

Re: 1977 evinrude/johnson 115hp ignition trouble

Are you sure the battery cables you made up are the same gauge as the ones you replaced? If they aren't they won't pass enough current to spin the starter.

 

[iwombat]

Re: 1977 evinrude/johnson 115hp ignition trouble

Make sure the ground straps on the coil bracket are in place and in good condition also. That whole bracket floats on rubber grommets, and if it's not grounded properly you'll have problems.

 

[phoneguy925]

Re: 1977 evinrude/johnson 115hp ignition trouble

emdsapmgr, the batery cables i made up are actualy larger than the ones that were original and are rated for high curent electric busses as for what iwombat sugested yes it is well grounded i even add a few extra ground straps because that thought had crossed my mind I am starting to think that ezeke is pointing in the right direction with the starter not turning the engine fast enough and i did the voltage drop test accross the starter and it sucks up a hell of alot of voltage and gets real hot fast when under load . so i guess my question is --is this a common thing with the sarters having them not handle the load of spinning up the engine.

 

[phoneguy925]

Re: 1977 evinrude/johnson 115hp ignition trouble

also if i am going to replace the starter what is recomended using a sierra or arco replacement?

 

[phoneguy925]

Re: 1977 evinrude/johnson 115hp ignition trouble

well thanks alot every one it turned out to be a week starter put a brand new one on the engine and wammo she fired right up.