asking for you thoughts on a 71 100hp

[toey77]

well the title says it all really just thought all the info I can get at this stage is great.. so I am asking for your 2 cent's worth on this subject. plus are they worth much?

 

[F_R]

Re: asking for you thoughts on a 71 100hp

Not meaning to put you down in any way, but after reading many questions/threads from Australia, I have come to the conclusion that motors down there are generally in pretty crappy condition. The motor in question was state of the art in 1971, but this is 2010 and by today's standards the '71 had a poor ignition system. The worst part was the distributor, not the breaker points. Newer motors don't have a distributor. Also, the amplifier is easy to damage (destroy) and expensive to replace.

We had an awful lot of spun water pump impellers back in those days, resulting in burnt-up powerheads. If the paint is discolored on the cylinder block, forget it. Unless somebody has rebuilt it. I repainted any that I ever rebuilt.

I guess it all boils down to the condition. If poor, it will be a money pit for sure.

 

[toey77]

Re: asking for you thoughts on a 71 100hp

most outboards down here are used in salt water 90% of there life in fact I have never been out on freshwater but I know of a place (1 only) that is just used for skiing in summer thats fresh water , and like all things maintenance is what people forget. I have one really clean looking motor (WITH WEAK SPARK) and one that looks like it never left salt water all its life. I will post pics of the blocks so you can see, cause your statement on discoloration of the block I assumed it was from the saltwater eating of the paint on the block will be interested to see what you think.. I will post pics up tomorrow night. I have never tried to crank the bad motor but I can move flywheel just out of curiosity I will give it a few revolutions to see if it binds up as well, I got this motor for the electrical system and the power tilt. and the bonus of what ever else I may need.

 

[toey77]

Re: asking for you thoughts on a 71 100hp

The motor in question was state of the art in 1971, but this is 2010 .

trust me if I could afford a 2010 or even remotely close to that age motor of similar capacity I would have one in a heart beat

 

[F_R]

Re: asking for you thoughts on a 71 100hp

trust me if I could afford a 2010 or even remotely close to that age motor of similar capacity I would have one in a heart beat

Hey, me too. But I have several antiques.

 

[ezmobee]

Re: asking for you thoughts on a 71 100hp

not to mention it's an electric shift......

 

[DJ]

Re: asking for you thoughts on a 71 100hp

I wouldn't buy it.

1. Electro Shift.

2. Weird ignition system.

3. A real fuel pig, even by engine standards five years later.

 

[ezmobee]

Re: asking for you thoughts on a 71 100hp

'73 or newer would be better. I'm thinking '78/'79 or newer even better (though I forget why )

 

[toey77]

Re: asking for you thoughts on a 71 100hp

well here are the two motors one good but weak spark an one for parts. I thought the discoloration was from oxidation as the motor has a lot of that on it

 

[emdsapmgr]

Re: asking for you thoughts on a 71 100hp

The picture on the right shows the factory final gold color has peeled off, revealing the red primer paint that is showing through. Possible the right one was overheated. On the other hand, the powerhead on the right looks pretty pristine-you need to do a compression check, then pull the heads for inspection of not only the cylinder walls, but also the water passages. You will find a lot of NLA parts on that year/model. These early 85 and 100 hp engines were small bore engines, around 92 cubic inches. The 71-125 was the 99.6 cubic inch displacement-like all the V4's after 1979. Their blocks and internals don't share much in common with today's engines. You need to check the condition of the wiring harness-the wires tend to crack/deteriorate with this much age. The electric shift lowers work fine, but are hard to find parts for. (Also-difficult to find any technician that has ever worked on one.) I really liked my 72 100 hp Johnson-it ran reliably for years till I sold it-still running.

 

[toey77]

Re: asking for you thoughts on a 71 100hp

the motor on the right is my parts motor only, i am not srtessed about it's compression as the one on the left is the keeper. tested its compression while back and got about 134 on each cylinder bar one which was about 128, so i thought that those figures were still nice and high and in good range. the motor on the right has a good loom so does my other one. but the parts motor also has power tilt which i am in the process of changing to my other motor I am also putting the lower unit on cause my good motor has a bit of damage to the casting. nothing major but II want the nicer one for looks.. Pictures show what I mean.

 

[F_R]

Re: asking for you thoughts on a 71 100hp

I don't see any overheat discoloration. Overheat turns the paint sort of brownish. As a further check, look at any wires that may lay up against the heads. The plastic shouldn't be melted.

 

[emdsapmgr]

Re: asking for you thoughts on a 71 100hp

Most marine shops offer skeg reweld/repair services, while it is still on the engine-if you don't want to get into swapping the lowers.

 

[toey77]

Re: asking for you thoughts on a 71 100hp

i want to do the water pump anyway, cause i know it hasnt been done for years so may as well change while i am there