Questions about purchasing a 1982 75 HP 3 cylinder Johnson

Texasmark

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Dec 20, 2005
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Thinking about purchasing a boat with this engine. Owners says it needs an impeller. I questioned back to him how does he know this. Did he overheat the engine?

Deades ago I was an OMC guy but have been a Merc. guy since. I always was impressed with OMC's Loop Charging process starting back with the Evinrude 55 HP Triump 3 cylinder with total engine/lower unit redesign from the old school 2 cylinder power houses with the gearbox that got hung up on everything and was hard (for me) to seal.

Question is, am I shooting myself in the foot on thinking about purchasing a boat with this engine or not.
Responses appreciated.
 

racerone

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Dec 28, 2013
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Those are an excellent / simple and reliable engine.------Hopefully it has the newer ( thick skirt ) pistons in it.
 

Crosbyman

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The seller may simply be alerting you based on his knowledge of the last time the impeller was replaced. The important thing is to check it mechanically, beat up or TLC'd engine ? Check compression, check LU oil (..yet super clean oil may just indicate a recent refill to hide a water leak problem). Keel ok no cracks?
can you at least do a water test or start it on a hose to see if it starts and idles ok.?

you know... all the usual stuff...incl paint discoloration on the block.
 

Crosbyman

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most of the 20 ....small 3-15 hp I have refurbished were 60+ years and run great without any big mechanical problems. Just ignition, gear oil, gc reseals .
Properly maintained, stored,,cared for & OILED properly they last forever.

but I never ventured into the big leagues :)
 

Mc Tool

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most of the 20 ....small 3-15 hp I have refurbished were 60+ years and run great without any big mechanical problems. Just ignition, gear oil, gc reseals .
Properly maintained, stored,,cared for & OILED properly they last forever.

but I never ventured into the big leagues :)
I think with smaller , like aux sized motors there's half a chance that its done bugger all work .... I have a 6hp Zuki , had it 3 years and it hasnt got 2 hrs on it , so your looking at the ravishes of age and poor storage rather than broken knackeredness .:)
 

cyclops222

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I bought a 1986, 9.9 and a 1998 30 Evinrude both bought brand new. I have done NO PM on them. Run every day in summer. Since 1986. PM 1 impellor. Thermostat parts in the 9.9. I only run NON E gas, high test, at a marina.
 

flyingscott

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It's a decent motor. I would replace the exhaust housing gaskets on the block and the impeller. Keep it propped to 5800 rpm and go boating. Do a compression test before buying and hopefully a test run on the lake
 

airshot

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This is why we run tests on things before we purchase them....without testing all we are doing is guessing. Next question is cost.....is it priced to allow normal replacement of wear and maintenance items ? We can't see, feel or touch, so anyone's guess.
 

Mc Tool

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Its the crankshaft assy that gives me the geebies . If its got rusty its custard but its hard to tell sometimes . I look as far thru the intake tract as I can to see if its dry , like corrosion on throttle butterflies or reeds if you can see them sort of thing , or it might be all crudded up with dust and oil , like you have to wipe your fingers after touching it .
When I mothball a 2 stroke I usually spray a 5:1 mix into the carb at idle until it dies
 

flyingscott

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lot of motors coming out of Extended storage that have no issues. by extended I mean yrs.
 

Mc Tool

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lot of motors coming out of Extended storage that have no issues. by extended I mean yrs.
For sure but unless you have the nouse , or a friend who does your not going to know for sure . I wouldnt recommend any non mechanical person buy one , specially if you want an aux for main engine back up , but if its for kids in a pond and there are others about ..... why not ?
Whatever you want it for I would give it death like your trying to break it (without abusing it) and if it can handle the jandle .........enjoy cheap motoring :)
 

flyingscott

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That is absolutely the motor somebody not mechanically inclined should buy. Simple motor and parts are cheap.
 
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