outboard engine knock.......

bob johnson

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Feb 25, 2009
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what are the possibilities and their ramifications over all?

I know of a late 90's ocean pro 90 hp 2 stroke that the guy says runs, but has a knock.

says it could be good for parts, or repair or to run unitl it dies....seemingly good price and it comes with guages, the binnicle controls, and cables.

I really would like to get into a bigger motor than the 70 i am putting back together now...but dont want to lay out $2500+ for a good running motor.

most times in regular motors( non outboards) knocks are bad rod bearings..

so If i were to tear this power head down..... what are some scenarios?

if i went with replaceing all wear parts how deep would I have to reach into my pocket...i am sure i could do it myself...and I am sure i wouldnt want to as well!!

but I love the price....

could I get the bearings replaced leaving the power head on the motor?

or does it have to come off to do that job?

thanks.

bob
 

tashasdaddy

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Nov 11, 2005
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51,019
Re: outboard engine knock.......

Bob, there really is not way to tell, till you break it down. going that far, you may as well inspect all of it. i would do a compression & spark,check before even buying it.
 

kenmyfam

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Aug 10, 2006
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Re: outboard engine knock.......

199% agree with TD on this. You just don't know till you get into it. The money you don't spend on parts could go towards a motor with no issues. The "run it till it dies" thing could leave you stranded, vulnerable and miles from shore.
 

F_R

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Re: outboard engine knock.......

Bearings don't go bad by themselves. They take the rods and crankshaft with them.
 

bob johnson

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Re: outboard engine knock.......

well it is supposedly running right now...enough to actually take the boat out...so i doubt the rod knock is that bad.

I was just trying to get a feel for the size of the possible repair a knock could throw my way.

the motor is a 1999,

a 1999 evinrude ocean pro 90 hp running good would go for at least $3500 around here. heck I have been looking at most any 90-115 hp from the late 80's running is at least $2500 and up!!

this guy is only asking $700 and it comes with the binnicle controls...which i want for my center console, and guages...dont know what they are.

so at first i think it is a good deal .

I knew that the reapir is an unkown, but usually guys in the know could say from $x to $z to fix a bad rod.

gaskets, a piston ,and rod, new bearing, being the cheapest

a new crank, a new rod and piston, and all new bearings for the crank the gasket set, maybe the worst


thanks

bob
 

freddyray21

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Re: outboard engine knock.......

right now if is is a rod bearing your are taking about fixing that. If you run it until is quits then who knows.
 

bob johnson

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Re: outboard engine knock.......

right now if is is a rod bearing your are taking about fixing that. If you run it until is quits then who knows.

well if I bought it, Id get right into the repair before i ever ran the motor again!

with out a doubt...

the guy is doing the same...he just offers to run her to let you hear it, but he is repowering new....

and luckily didnt run it unitl it died

I have a 2070 lowe Ultra roughneck..and am now almost ready to reassemble my completely dismantled 1988 70 evinrude...

but I have the motor already so i figure Ill put it together and put it on my boat, until such time as i get a bigger more suitable size motor like a 90-115hp 2 stroke.

so i would have all summer to get the bigger motor running..and if i spent a grand...I would still be way ahead..( because i need to buy a binnicale control anyway for this boat for one)

bob
 

R.Johnson

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Re: outboard engine knock.......

Does this engine knock all of the time , or just on deceleration? If it knock's only on deceleration, and you hit the fuel primer, and the knock goes away, what you are hearing is like a lean fuel knock. Not unusual for V-4's in this time frame.
 

F_R

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Re: outboard engine knock.......

A rod bearing which is bad to the point of audible knocking won't run five minutes. That isn't it. But could be a blown piston.
 

bowman316

Lieutenant Commander
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1,822
Re: outboard engine knock.......

try running 93 octane, this has a higher anti-knock rating i know.
but i don't know if this refers to the same type of knock you are refering to or not.
 

bob johnson

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Re: outboard engine knock.......

I only have the info, i havent seen nor heard the motor yet.
I wouldnt want to go see it till I got more info from the forum here...

because if i want it...I want to buy it right then, not make a whole other trip to go get it later

bob
 

bob johnson

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Re: outboard engine knock.......

well I found some more info... he says he has had the knock since he bought it last summer. He took it out about 15 times, and he goes to some possible rough water places in the ocean and he was getting worried about the noise and wether it might leave him stranded out there.

so his wife said to get a new motor!! because he takes his kids.

he said the motor is super clean zero corrosion, and it is kinda hard to start a lot of times..

so I think it might not be a rod knock....

I am going to look at it friday.....

one issue is he just bought a new motor and took this one off already and has it tied to a tree, because he thought laying it down my cause trouble or lert the lower unit oil drain out....so it sounds like it it entirely possible the noise is easily fiable, because he seems like a novice boater motor owner.

so i wont be able to hear it run now....

bob
 

bob johnson

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Re: outboard engine knock.......

does anyone know if this motor is fuel injected or carbed? also if it is fuel injected is it a FITCH motor?? heard bad things about them

the NADA guide lists only one 90 hp 2 stroke for 1999.... did they ONLY make OCEAN PRO models that year?

if not what is the difference between the OCEAN PRO line and the other line

thanks

bob
 

R.Johnson

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Re: outboard engine knock.......

Bob: I couple of summers ago I had a engine come in with guite a knock. Listening to the engine, the knock really sounded like it was coming from the powerhead. Turned out to be a broken pinion gear. You really can't just jump to conclusion's with these engines.
 

bob johnson

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Feb 25, 2009
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4,306
Re: outboard engine knock.......

Bob: I couple of summers ago I had a engine come in with guite a knock. Listening to the engine, the knock really sounded like it was coming from the powerhead. Turned out to be a broken pinion gear. You really can't just jump to conclusion's with these engines.

and it could still be put in and out of gear?

well someone was going to look at it saturday...I have to work my dog at a tower shoot saturday and figure if i went on sunday it might be gone...so i am going friday....

i may take another chance...

(my 70hp is in peices!! ha ha)( but at least it will have a great paint job soon)

bob
 

Willyclay

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Re: outboard engine knock.......

The experts on this forum, which I am NOT, can help you solve most any problem. From my experience, I want to make you aware of another source of noise that some people might describe as a "knock" but I call it a "clank". A bad motor mount on my V-4 Johnson allowed enough movement of the powerhead on acceleration that it would contact the housing and make a very audible sound. This was not a rotational noise with engine RPM's. Good luck!
 

Dhadley

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16,978
Re: outboard engine knock.......

R Johnson has asked a very important question - does it knock while at a steady cruise or only when you decellerate (chop the throttle)?
 

bob johnson

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Feb 25, 2009
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Re: outboard engine knock.......

he took it off the boat this past weekend...so i can't run it .....I could try to rig it up with muffs and start it......

I dont know if it has oil injection or not.....just another thing to try and geery rig to start it up

he bought a 115 e tech for $9100 with prop no controls....seems like a good deal doesnt it?



I am probably just going to buy it if it is as clean as it looks in the photo...

I could get my $700 just by selling the lower unit alone!!!

my yard will become an outboard motor junk yard soo, i fear

bob
 

iwombat

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Jul 12, 2006
Messages
3,767
Re: outboard engine knock.......

I bought a parts motor with a "knock" for $100 last winter. I never heard the noise myself, so I assumed I had at least one bad hole or a bad crank. After tearing it all apart, it turned out to be a bad exhaust gasket.

You just never know until you tear it down.
 
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