Evinrude 115hp question

[Hukeedo]

Just bought a 79 Sportcraft 17 footer with a 1979 evinrude 115 motor. Runs on 3 cylinders, which i knew going into the deal. The guy says he thinks it may be low on compression in one cylinder, but he didnt have it checked. He just assumed this. I will check for spark, and change the plug and check compression on the cylinders, but my question is this, how difficult is it to put new rings in these motors? Are the powerheads easy to remove to rebuild? I got the whole rig for 250.00 because i love the boat and it's in great shape. I can put another motor on it for what i paid for this boat but wanna give this one a shot first. Any info is appreciated guys.
Thank you.

 

[1946Zephyr]

Re: Evinrude 115hp question

Well, I would pull the head on the low cylinder side and see if possibly the head gasket is bad, or if the cylinder is marred up from a busted ring.

 

[emdsapmgr]

Re: Evinrude 115hp question

You seem to be assumning that an overhaul is required. You need to test the compression yourself before you do anything else. Then do the check Zephyr suggests. Sometimes carboned rings will affect compression. You may just need to decarb the engine.

 

[itsaboattime]

Re: Evinrude 115hp question

Well, I would pull the head on the low cylinder side and see if possibly the head gasket is bad, or if the cylinder is marred up from a busted ring.

X2.
May be a stripped spark plug hole, blown gasket, bad rig or any number of things.
pull the head(don't break the bolts or pull any threads) and give it a good eyeball. Easy stuff first, then goto hard.

 

[noelm]

Re: Evinrude 115hp question

not too sure why you are ready for an over haul! you have yet to even test the compression, don't perfom major surgery for a minor illness, I see from your "replace the rings" comment that you are not 100% familiar with 2 strokes, so, do yourself a huge favor and buy a GENUINE manual for your motor, not a cheap ebay CD or generic manual, but a genuine one.

 

[boobie]

Re: Evinrude 115hp question

As said above , check the compression FIRST!

 

[Hukeedo]

Re: Evinrude 115hp question

You are correct in that i am not familiar with rebuilding a 2 stroke boat motor. I was just wondering how difficult it is to remove the powerheads on these motors. I will check all the above mentioned for sure, cold weather is preventing me from that right now, but i will be getting it into a garage here soon with heat. I am hoping that it may be something pretty simple. I am mechanically inclined, I have rebuilt car engines, and my 2 stroek motocross engine with no problems. Thanks for the advice and info, i do plan on getting a manual for the motor before i would do any kind of major surgery on it if that were the case.

 

[emdsapmgr]

Re: Evinrude 115hp question

You need to get an original factory manual for that engine. Outboardbooks.com has them.

 

[kenmyfam]

Re: Evinrude 115hp question

Check compression and check spark. Go from there. Agree with the others, diagnose before considering doing any work to it.