Suspect Engine Coupler Failed

[Fisnfool]

To give a short history:

We were in the Grand River heading out to Lake Erie. We we doing about 3mph and my wife was at the helm. The engine blower was running and I did not notice an overheat smell until it was too late. When I turned and looked at the gauges the temp gauge was pegged. We shut down and came back in using the kicker.

I pulled the outdrive lower unit and replaced the complete water pump. The housing was melted from the overheat when the impeller failed.

Now the main problem.

First trip out since the overheating. Engine ran fine and I stayed in normal temp range. I went out 3 miles to a good perch fishing spot and did well.

When I started the engine to come back in, there was a high pitched whine and shifting into gear gave no thrust. I shut down and tried a restart. Same high pitched whine. I immediately shut down again and used the kicker to come in.

Does this sound like an engine coupler failure?

1965 100hp 4 cyl inline on a Statecraft Holiday.

 

[HT32BSX115]

Re: Suspect Engine Coupler Failed

Howdy,

Mercruiser, OMC, Volvo, Lausen Power Products, Briggs & Stratton, Scott Atwater?


Possibly. Look in the back with a bright light and look for metal or black powder behind the engine......If you see that, pull the drive and look at the coupler with a flashlight. When mine failed, it looked like someone drilled the coupler out. (the inner splines are aluminum)


If you can see the drive yoke where it enters the coupler, you might see that metal on the yoke. If the boat is still in the water you can start it and see if the shaft turns......, put it in gear, and see if the shaft continues turning.

If the shaft stops turning when you put it in gear, the coupler has failed. If the shaft continues turning, you may have a spun prop hub.

 

[Gary H NC]

Re: Suspect Engine Coupler Failed

Could be.Was there any smell of burnt rubber?

Also when the drive was off was the alignment checked?

 

[Fisnfool]

Re: Suspect Engine Coupler Failed

Could be.Was there any smell of burnt rubber?

Also when the drive was off was the alignment checked?

Yes to both. I have the engine alignment tool.

HT32BSX115

OOPS sorry about that. Mercruiser.

I trailered the boat. With the engine off, shifting into forward or reverse, locks the prop as usual.

Using a spot light, I can see some shavings. I put my finger into the stern drain plug hole, and the residue feels gritty.

I would guess that the only way to replace the coupler is to pull the engine. I have the old merc service manual for the boat and it does not list the engine coupler in the index.

 

[Gary H NC]

Re: Suspect Engine Coupler Failed

Bummer,
Yep,pull the drive then the engine.
At least it being a 4 cylinder it won't be bad at all.

I have pulled a couple 3.0 motors,drilled out broken starter bolts and had it back in and finished the same day.

 

[bigskiohio]

Re: Suspect Engine Coupler Failed

wont take long, three guys could be pitman and do it in 3hrs i'd say on a older 4cyl. what sisze of boat is it i have been wating to go on lake erie but it kind of intimidates me,

 

[LAC_STS]

Re: Suspect Engine Coupler Failed

I have a 5.7 OMC but if I look behind the engine I can see the coupler and actually feel where the drive shaft enters it and feel the rubber between where the spooned are and where the outside of the coupler are

 

[Fisnfool]

Re: Suspect Engine Coupler Failed

wont take long, three guys could be pitman and do it in 3hrs i'd say on a older 4cyl. what sisze of boat is it i have been wating to go on lake erie but it kind of intimidates me,

It is a 19 foot closed bow Starcraft Holiday. I often take out 3 friends that come up from Norton.

I am retired. Pm sent for open seat contact.

If I had more experience owning a I/O I would have changed the coupler last year. When I was out in 4 footers one day last year, the engine surged a few times and I jut thought it was the outdrive angle too high pulling out of the water in the swells.

Now I know it was the coupler slipping under the strain.

I can use the large tree in the yard to rig a hoist.

 

[HT32BSX115]

Re: Suspect Engine Coupler Failed

Back with my previous boat (1966 MarkTwain 150 Mercruiser) I had a similar experience.

I was cruising around the lake and it acted like it was briefly or intermittently, jumping out of gear!

I didn't think it had anything to do with the coupler.

The next day we came back to the lake and put the boat in the water.

After starting the engine and selecting REV, it went right into gear, but started "slipping" almost immediately!!

I had to paddle back to the dock!!


Like I said earlier, when I got the drive off it looked like someone had drilled out the coupler!

The coupler was the original one! 39 year old! You will be removing the engine. Not a bad idea anyway. You can inspect the oil pan, riser, exhaust manifold, water shutter, etc.


Cheers,


Rick

 

[Fisnfool]

Re: Suspect Engine Coupler Failed

The coupler was the original one! 39 year old! You will be removing the engine. Not a bad idea anyway. You can inspect the oil pan, riser, exhaust manifold, water shutter, etc.


Cheers,


Rick

THANKS FOR THE TIPS

This may be the original 1965 coupler too. I bought the boat 3 years ago. The original owner had all the service paper work including the 2005 engine rebuild.

I can not find any bill for the coupler. He kept everything even just winterizing bills. Neat to know when the deck was replaced and electrical work done. With all the service, almost everything was upgraded over the years he had the boat.