New Powerhead

[patsmith]

This is my first post to Iboats, so hello everyone! There sure seems to be some great knowledgeable people on these forums here, so I sure hope some of you can help me out.

I have a 1985 115 Evinrude that the powerhead is shot on, which I got for some work I did for a friend last year. I have been looking at some of the rebuilt powerheads here on Iboats and I am wondering how big of a job it is to install one. The outboard is in pretty good shape except for the powerhead has the lower unit was completely rebuilt about two years ago , and there is not I lot of rust as it has never been operated in saltwater. The only problem with the powerhead is that it is completely worn out, so I have thought of having it rebuilt, but with some of the prices on rebuilt heads, I think that might be a good way to go. Therefore, I have been wondering how big of a job it is to change one. Any advice would be great.

Pat

 

[emdsapmgr]

Re: New Powerhead

An original OMC service manual and a couple of hours of labor and you can pull the powerhead and install the new one. You will need an extra person, or an engine lifter to assist you with the lifting. Connecting up the fuel, electrical systems and control/steering cables will take another couple of hours. The timing pointer will need to be reset and the engine will have to be timed before you start running the powerhead. Watch for the powerhead you purchase, yours is a flatback. Later model 115's will fit, but are the bubble back type and need larger carbs. Plan on installing new plugs, carb kits, thermostats, new water pump impeller and a new fuel/vro pump to insure all critical parts are new. Contact the original printer, Ken Cook, Co., in Milwaukee for the service manual. They will take your credit card and send you one UPS. You can look at original Parts lists on line. Google for this address: epc.brp.com.

 

[BoatBuoy]

Re: New Powerhead

Just for my own curiosity, what are the symptoms of it being worn out?

 

[Dhadley]

Re: New Powerhead

Ditto. Describe "completely worn out".

 

[funpilot]

Re: New Powerhead

I would not be surprised that if you have the mechanical ability to pull the power head with the help of a manual, that you would have the ability to rebuild the power head by asking questions here as you go. It's a lot of fun, and the folks here love to help.

good luck,
fp

 

[patsmith]

Re: New Powerhead

Thanks for all your help so far. The engine has many thousands of hours on it and has already been rebuilt (including rebore and oversize pistons) about ten years ago. The current compression is 88, 22, 77, 44 and the previous owner told me that a bearing is going. How easy is it to find parts, oversize pistons for a second rebuild, etc? I am a automotive mechanic so I do not have any problems with mechanical matters, but this is my first time working with a outboard (at this level) and rebuilding a two stroke motor. Any more thoughts would be super.

 

[iwombat]

Re: New Powerhead

If you've got experience in automotive, you can tackle a 2-stroke outboard with no problems. All you're lacking is a couple of trips around the block with the specifics of your particular engine. The folks here have been around that very same block several times over.

Take some pictures and ask lots of questions and you'll glide through the whole process.

 

[funpilot]

Re: New Powerhead

Besides what iwambat said, aluminum block machining is different from cast iron block machining, so find a machine shop with that experience. Bearings, gasket sets and pistons are readily available from iboats. If you let your machinist select your pistons for you, he will machine specifically for the replacements.

A lot of good information is here that will help you link and synch your engine, set your carbs, and break in your motor. Just do some searches before you ask questions, but even repetitive questions get answered quickly!!!

With new bearings, your rebuild will run you under $1,000, and can be tackled in no time. I find it easiest to undress an engine one night and lift it off (a lot of folks drop the lower unit first, saves wear and tear on the splines) tear the engine down the next night, wait a week or two for parts and machining. While I'm waiting I rebuild the carbs, and check out other components like the starter and the stator, and T-stats. Some replace T-stats, I check them in a pan of water, if they function, I figure they're good to go. I build the engine in one night, install it and dress it the next, and then do my set up and link and synch. My break-in is harsher then some use, but I like to seat my rings as quickly as possible.

good luck,
fp

 

[patsmith]

Re: New Powerhead

Thanks, I assume the link and synch is just a normal adjusting of the linkage and setting the spark advance, timing, etc? If someone could post some procedures for this and setting up the carbs, that would be great.

I was down at my local dealer yesterday and they have a Seloc L3, V4, and V6 1973-1991 Tune-up and Repair manual, which also says is a certified textbook, is this a good manual to go with? I have not got it yet, as it?s in a wrapper and they do not want you to remove it, so I was not able to look it over.

 

[funpilot]

Re: New Powerhead

Pat,

I use a Clymer manual which is supposed to be worse than the Seloc, which is reported to be worse than the factory's. You can order a factory manual from Ken Cook as emdspamgr mentioned above.

In another thread on this page http://forums.iboats.com/showthread.php?t=194864 Joe Reeves shares his Link and Synch method, which is the defacto standard here on the forum if you can't run your motor higer than idle to check your timing. Yes, Link and Synch is exactly what you think it is. It does include checking for TDC in the usual manner of measuring the halfway point between top piston travel using a stop. The factory method pretty much requires a prop wheel to run the engine at high speeds in a test tank.

good luck,
fp

 

[BoatBuoy]

Re: New Powerhead

Dhadley could offer more here, but Wiseco offers pistons .020, .030, .044, & .064 oversize for that motor. According to the BRP site they only offer .030 oversize, so if it was rebuilt/bored for BRP(OMC) pistons, looks like it could be bored again if cylinder wall damage is not too deep.

I rebuilt a 2-cyl 35hp when I was 19 or 20 with limited knowledge, skills, abilities, or tools; and IT RAN afterwards. With patience, iboats forums, and a manual, I'm sure it would be no problem for you.