1970 Evinrude 115 4-Cyl Dies after 5-10 minutes

[GraphicByNature]

Hi. I'm new at boating and inherited the above motor. It runs great and starts immediately when cool. Then, after running at any speed for 5-10 minutes, it totally quits and refuses to even think about starting until cooling again. I've heard everything from coil to thermostat to impeller, but don't quite know where to start as my resources are limited. Engine is hot, not warm, when it shuts down. Can anyone tell me the most likely place to start narrowing this down please and what to look for? I'm going in what seems like 1,001 directions and would appreciate narrowing it down to a mere 1,000. (I'm really tired of rowing too.) Thank you!!!

 

[Solittle]

Re: 1970 Evinrude 115 4-Cyl Dies after 5-10 minutes

Welcome GBN - Lots of help here! Some of it is even worth reading.<br /><br />Outboards are cooled by the flow of water through the motor under pressure. The flow and pressure is provided by a water pump and thermostat. I recommend that you replace both. Oh - and buy a manual for your motor if you don't have one. It will pay for itself in this one repair.

 

[GraphicByNature]

Re: 1970 Evinrude 115 4-Cyl Dies after 5-10 minutes

Thank you for the welcome.<br /><br />I've noticed the amount of knowledge here by reading many of the posts and am soaking it up eagerly.<br /><br />Thanks for the advice on the pump and thermostat. I will try it. This thing runs great until the shutdown.<br /><br />As for the manual... I ordered one as soon as I got the boat and it should arrive any day now. Thanks again!

 

[reeldutch]

Re: 1970 Evinrude 115 4-Cyl Dies after 5-10 minutes

are you shore it is running hot?<br />when you put your fingers on top of the heads you should be able to hold them for 3 sec and then it will feel hot.<br />thats normal.<br />when you put yopur finger on it and have to pull away imediatly and you think your finger is burned you are running hot.<br />chaging tstats and waterpump and waterflow deflectors are always good to keep your engine on the right temp.<br />if it will solve you problem ,i dont think so.<br />i think you have a problem with ignition.<br />it is weak.<br />weak coils will loose current when warmed up.<br />when it happens again check for spark on all you cylinders.<br />thats how i would start.<br />when you take out the plugs check if there wet or dry.<br /><br />good luck<br /><br />reeldutch

 

[GraphicByNature]

Re: 1970 Evinrude 115 4-Cyl Dies after 5-10 minutes

Thanks for the additional advice. The heads are definitely hot to the touch.<br /><br />I drained the lower unit last night and the oil was very milky, so there are apparently seal problems which can't be good. Seals, water pump, and thermostats.... right? On to coil if problem persists?<br /><br />Luckily these parts are affordable. I'm just hoping I can find and stop the problem before it gets too expensive or time consuming. Thanks again!<br /><br />Steve