118,120,55 compression on 70hp johnson

[duke1012]

so my question is should i keep it for a project ,,keep in mind I have never rebuilt anything lol,,I already put a 175 evinrude on my boat which is what the boat is rated for ,but i really dont want to give this away a guy offered me 250 for it ,,but the tilt trim cost me more than that and everything else is good with the motor it starts right up and runs ,please help tell me if i should take the cash or should i just build a stand and keep the thing and try to rebuild

 

[Haffiman]

Re: 118,120,55 compression on 70hp johnson

I guess it may be a question of 'birds on the roof or birds in the hand'.
The engine clearly needs a rebuild, are you going to do it?

 

[duke1012]

Re: 118,120,55 compression on 70hp johnson

Well how hard is it to do and yes that is a serious question I can follow instructions and I really don't need the motor or the money I figured if I am succesful I then will have excuse to buy a pontoon in the spring but I also don't want to spend money on parts that I have no idea what to do with is it possible to rebuild just the one cylinder

 

[Haffiman]

Re: 118,120,55 compression on 70hp johnson

Start by investing in an OEM workshop manual, that might give you an idea.
However do not just leave it in that condition. If not properly fogged down and preserved, by the time you want to start, corrosion damage may be more than the mechanical damage. Crank shaft and bearings are not happy standing for years.
Difficult?
The first is the worst, but if a decent 'do-it-yourself' mechanic and some tools, everything is possible.
We all had a first time .

 

[emdsapmgr]

Re: 118,120,55 compression on 70hp johnson

Depends on what failed in the engine. Pull the head and have a look. Check the head and the cast iron cylinder walls. You need to know what caused the failure before you start to rebuild it. Does the carb that feeds the bad cyl. have debris in the jets-restricting fuel flow? It is really not a complicated engine. If the engine has a lot of hours, you may find the other cylinders are tapered out of spec and they all may need to be bored. Depends on what you want to spend...You can ge an original factory manual from Ken Cook Co., in Milwaukee. Usually during an overhaul you would want to replace the impeller, thermostat-maybe even the OMS fuel pump...

 

[Haffiman]

Re: 118,120,55 compression on 70hp johnson

If pulling it apart to have a look and then putting away for later 'fun', buy some Zip-bags.
Spray the parts with preservation oil, put in the bags and zip!
Keeps them clean, no air and corrosion.