bad coupler?

[bigskiohio]

I think mines bad boat wont go and people by the back said they smelled rubber.
shifter engages with little effort but prop ratchets when in the right position. Also when i crank engine get squeal noise. Will rotate engine and see if shaft turns. 1973 120 mercruiser ran great but treating it like a jet ski while tubing is a no no. what a idiot i know . Probably needed outdrive removed and serviced anyways. will work on it as soon as it warms up in nw ohio. Hope i didnt hurt outdrive. does the sqealing when cranking sound familiar?

 

[JustJason]

Re: bad coupler?

if the boat doesn't go when you put it into gear and you smell burning rubber under the doghouse, then yes. Your coupler is probably bad.
I don't know what you mean about treating the boat like a jet ski but if you check the engine alignment every year the coupler should last almost for life.

 

[Don S]

Re: bad coupler?

Have you tried opening the engine compartment and looking to see what might be wrong? Could be a bad shift cable causing it not to shift properly and a locked up alternator could cause the belt to slip, smoke, and squeel when cranking over.

 

[bigskiohio]

Re: bad coupler?

i was hitting some 3-4 ft waves and was going into a turn when it just revved up. and it wouldn't go , my son sitting on the jumper seat said he smelled rubber i couldn't steering the boat. I tried running it in driveway real quick and could not really see if shaft was turning not much room. Boat is a 1973 120 mercruiser so its 30 + years old, so i would say its a lifetime already. I kind of thought shift cable but wasnt sure how to check it. local merc mech said 700.00 to fix coupler. Due to unsure job and economy i will try to fix myself. But he never looked at it just diagnosed over phone. just worried i stripped gears or shaft. but it does seem to shift okay and rachet ,will check tomorrow a little more. what tests or inspections should i do to diagnose the problem. It never squealed before when starter cranked . do you think it would spin prop in driveway even if coupler slipped? It also shifts into gear with little pressure on shifter just odd as usaully it takes good force to shift, maybe because engine not attached due to bad coupler?

 

[Don S]

Re: bad coupler?

If the rubber part of the coupler did give way, at low rpm and no load, it will still spin the prop, just like a spun prop hub. But it usually doesn't cause a squeel.
It's going to take some looking and troubleshooting to find the cause. A spun coupler is only the final outcome from another problem you don't even know about.

 

[bigskiohio]

Re: bad coupler? It is a bad bad coupler!! right

Re: bad coupler? It is a bad bad coupler!! right

I finally figured out where to look at shaft not much room there is a small area shaft is exposed. Anyways put boat in gear and prop worked okay by hand in ratchet direction and stopped in other. But if you put just a little more pressure
on it, prop would turn and shaft would turn inside boat and it made rubber sound. engine was not stopping shaft from turning, so coupler is shot, cable seems to shift good . Will remove out drive today and i am going to try Tungsten marine coupler it is 80.00 and looks like original. If it lasts just one season or more we will find out. i want pressure test outdrive anyways as i ran motor on muffs i didnt tell my helper to turn water on easy and i had clean water in my lower unit . replaced it an it ran great on vacation but it made me wonder if i did any damage to seals. If i am missing anything let me know. Hope leg comes don't know last time it was off. will post pictures as i go .

 

[boat1010]

Re: bad coupler?

The coupler on my 89 Arriva went out on me. $1,00.00 later it was running again. Well the place that did it did not align it right and about 6 hours of running went out again. Make sure the alignment is correct when you replace it.

 

[JustJason]

Re: bad coupler?

eagh... you shoulnd't be able to turn the prop in the other direction... and you shouldn't try to either. You'll end up spinning the water pump backwards which is a no no.
Jumping a boat usually twists the propshaft first. In extreme cases it can break the verticle driveshaft. Before you pull the motor, pull the lower, remove the prop, and spin the driveshaft by hand and shift it by hand. Make sure both shafts look true.

 

[bigskiohio]

Re: bad coupler?

Doesnt the rachet in the clutch keep it from the wrong way. The solid direction is because motor is there. Mine would easily because coupler gone so out drive not connected to engine. Though your comment on impeller makes sense if you look at impeller design and shape. I will watch on startup to see if impeller is pumoing water if not i might try changing out with new kit, but will try to do more reading on that subject as it sounds a bit tricky. Wonder what mechanic would charge for job.

 

[bigskiohio]

Re: bad coupler?

I t is a bad coupler and when it went that was it it did not want to go any where no matter how slow i ran engine .

 

[Robj]

Re: bad coupler?

Or is the bad coupler just a symptom of another problem? Why did the coupler go, engine out of alignment, due to weak/rotten engine mounts? I would do a little more investigating as to what caused the problem. You need to find the cause and rectify that.

Have a great day,

Rob.

 

[bigskiohio]

Re: bad coupler?

How about being 35 yeaars old and i was beating on it having anything to do with it? I will be checking alignment and mounts when i pull engine to install coupler. It is a aluminum boat so not to much wood but will check. Thanx