Rebuild or exchange?

[reelfishin]

I have a 1977 140 HP Johnson V4 that is starting to lose compression, I just got the motor and have no idea how it was run or cared for. I plan to use it on another boat of mine once I rebuild it. My question is: Is it better or or more cost effective to rebuild the motor myself, or simply to exchange the power head for a reman unit?
My concern is with finding someone local that can do any required machine work. I have had nightmares with standard automotive machine work lately and can't imagine who I would trust to do the work on a two stroke. If it were only a minor hone job needed I would do that myself, but I do not have the equipment here to rebore a block, let alone such a small bore.
The motor is still running but has low compression on the right lower cylinder and some light scoring of the cylinder wall starting. It's all original and most likely can be overbored. I would be looking at 4 new pistons, bore 4 cylinders, a gasket set, and what ever bearings it may need.

 

[tashasdaddy]

Re: Rebuild or exchange?

my suggestion is to price the rebuilt head. then calculate the cost of you doing the rebuild, your labor is cheaper (maybe). as far as the machining. as around who does the local shops. also call the machine shops, and ask if they do it. then ask for some customers so you can check there work. if they are as good as they say they are, they will give you some references. i believe in doing my homework, before giving someone a critical job. actually NAPA has a machine shop here that does great work on 2 strokes.

 

[hoeser]

Re: Rebuild or exchange?

Not sure about your machine work issue, I didn't have mine done locally - sent it away to a very reputable shop a few hours north of here known as "Marine Medics" - they did awesome work on mine... it's in Canada though.

I bought my entire rebuild kit on ebay for $490 usd which included 4 new piston kits, gaskets and bearings for both ends of the connecting rods. Worked out quite well. I have an 84' Evinrude 140 by the way which is basically identical to what you have.

Just out of curiosity have you tried a decarb? You might find your compression normalizes with something that simple.