1993 Evin 115hp rebuild or not

[abody711]

Pulled the head on the motor today. Pics are of cyl that was running 100 on compression. The head appears to be shot. The cyl walls do not appear to be scored. Ran thumbnail around wall and felt no scoring. Compression was 110-110-115 on other pistions. Is this a project that someone of average mechanical ability should tackle? Have rebuilt car engines in the past.

 

[HybridMX6]

Re: 1993 Evin 115hp rebuild or not

it appears at one point in time that engine ate a ring. I doubt it would pull 100psi compression on one ring or none, but perhaps it could. I did a full rebuild on a 1992 3cyl last year, so I'd have to say it's completely possible for you to do it yourself. I had rebuilt 2 car engines in the past, and this one was really no different. I'd recommend purchasing a factory service manual for this engine if you intend to do the work yourself, and find out what caused it to do this. I spent around $1000 in parts, which included a new water pump and t-stat as well as all the required engine parts. You will at least need one new piston and rings. Make sure you have a marine machine shop check the block for out-of-round and all that, and so the required boring/honing. Most auto machine shops are not familiar with outboards and may not take the necessary steps required for a marine block.

 

[ezeke]

Re: 1993 Evin 115hp rebuild or not

Rebuild kits are available that contain the needed parts: http://www.powerheadkit.com/johnson.htm

 

[emdsapmgr]

Re: 1993 Evin 115hp rebuild or not

The 115 was a solid engine and made good torque with the bubble back exhaust. With your experience, you should be able to overhaul it with a factory manual. Get a factory manual from Ken Cook Co., in Milwaukee-or they are on the web. You should also replace the other three ringsets when you have it apart. I'd replace the head, too. It would be nice to know why it failed so you don't have a repeat problem after rebuild. For instance, was there carbon accumulation around the rings (an occasional can of Engine Tuner will solve that) or was there debris in one of the jets in the carb that restricted fuel/oil flow and ran the bad cylinder lean, etc? The factory permits an overbore on just one cylinder, should you need to consider it.

 

[reeldutch]

Re: 1993 Evin 115hp rebuild or not

i think when you take the motor apart you wil see the rings are not broken off.

i think you have preignition.
you wil still have to replace the piston and find out why.
carburator would be suspect or poor fuel octane level.

 

[baiwan]

Re: 1993 Evin 115hp rebuild or not

Thanks for the address of Powerhead kit, I need crankshaft bearings and will try them.

 

[jonesg]

Re: 1993 Evin 115hp rebuild or not

www.outboardbooks.com

for the shop manual,$40-50.

 

[abody711]

Re: 1993 Evin 115hp rebuild or not

Thanks for all the input. Factory Manual has been ordered. Will jump into tear down after Christmas. The married guys will understand why it needs to wait until after Christmas!!!!!!