Making old 115 reliable

[dogwhisperer]

I got a great deal on an 1978 johnson 115($300 boat motor and trailer)about 10 months agverall motor looks pretty clean and after rebuilding the carbs,new water pump,thermostats,lower oil change and plugs it runs down the lake at 42 mph pushing my 18' alum. starcraft w/cuddy cabin,not to shabby and could use some prop work (refurbing starcraft also).Compression also is mid 120's PSI on all 4 cyl..But after warming up it can get a little hard to start and will not idle very good.Could just need timing set.Question is,especially since ive got so little in it,would it be a waste to replace some of the elec components..such as coils,packs,and ?????? im not sure i just want it to be as reliable as it possibly can be..Any advice on what would be the best move here..Also saw elec parts by an aftermarket company..think it was GLM..anybody know if they make good stuff?? or stick with OEM???

 

[Solittle]

Re: Making old 115 reliable

You rank as being among the few who are doing the right thing with a "new to them" motor. I would go ahead with a sysnc & link + timing check. That may take care of the hard starting.<br /><br />I see no need to start replacing stuff that appears to be working just fine. If & when you do use the OEM parts.<br /><br />A couple of things you may have already done but did not include in your post - do you have an in line fuel filter/water seperator? Do you have a two battery setup? Do you have a tach? Water pump pressure guage? That is where I'd put my money if you haven't done so already.

 

[DJ]

Re: Making old 115 reliable

You may want to do a decarb too.

 

[BrianTindall]

Re: Making old 115 reliable

As far as replacing electricals, "If it ain't broke........". Carrying a spare coil, wire, and maybe a power pack is a good idea if you're not comfortable with the motor yet. But that's your choice. Run the engine at night with the hood off and look for any sparks jumping from the coils and wires, no sparks, then leave it alone. Clean the coil wire contacts/posts as well with a scotch pad. This may help somewhat. Go for the simple things first like the timing as posted above. My 1982 115 ran for 5 years after I rebuilt it in 1993 (bought it blown) and only replaced one coil, all the rest was original.