Engine Coupler... Need opinions

[Friscoboater]

I am repowering from a 305 to a 350 and I was wondering if I should replace the coupler while I am back there. The boat is a 1981 Glastron and the coupler is original, but looks fine. Do these things fail often?

 

[system-f]

Re: Engine Coupler... Need opinions

I too have thought about this. My coupler looks perfect, though, and I have no doubts mine is in good condition. If you have any doubts I would replace it, especially with the extra power you might have.. Pics of your coupler?

 

[Bondo]

Re: Engine Coupler... Need opinions

the coupler is original, but looks fine. Do these things fail often?

Ayuh,... They Fail All the time,....Quickly Too...
It's usually from a lack of Grease, or pizz poor Alignment....
Sometimes, but rarely from Excess HorsePower....

Your visual Inspection should include the roundness of the mounting bolt/ stud holes,...
The general condition of the Rubber,+ it's interface with the metal,..
And,...
The flatness of the tops of the splines....

If found in serviceable condition,... Go with it...
Just be sure to keep it Aligned,+ Greased,... It'll last darn near Forever...

 

[Friscoboater]

Re: Engine Coupler... Need opinions

Here are a few pictures. I can still read the manufacture date stamped on the rubber. August of '79.

There was plenty of grease on there, and the splines look great.

 

[HT32BSX115]

Re: Engine Coupler... Need opinions

Couplers do last a good long time!

I had to replace a coupler on my last boat, a 1966 Mark Twain with a 150 Mercruiser installed.

Dad bought it new. I replaced the coupler 39 years later. It had nearly 3000hrs on it.... (estimated...the hr meter failed in the early 1980's at about 1600 hrs or so)

When I replaced it it appeared that someone had drilled out the inner splines.



Cheers,


Rick

 

[fishrdan]

Re: Engine Coupler... Need opinions

It's hard to tell from the pic since the splines are hard to see, but they look "pointy" to me. If so, the coupler is garbage, lots of wear on it. The tops of the splines should have flat tops, about 1/8" or so from what I remember.

Clean off the grease and post a close-up pic of the splines so the guru's (not me) can see what you have there.

 

[sarantis]

Re: Engine Coupler... Need opinions

i think you miss something important.This coupler is for a 305 of earlier vintage whic means two piece rear seal whereas a 350 of later vintage is one piece rear seal which takes the biger flywheel and the triangle coupler and some conversion to the flywheel cover to fit it and a different starter (or if you find a 350's used starter to replace only its housing).There is also an conversion coupler from Sierra where you could keep your old flywheel but i don't know if the smaller diameter flywheel at a 350 you cause any problems to its performance.In adition if in the future you want to place a Bravo outdrive you will need to replace again your coulper whereas the triangle one i think works with the Bravo outdrive.Not so easy task.Search some threads or my older threads before swaping and you will learn a lot.

 

[Bondo]

Re: Engine Coupler... Need opinions

Ayuh,... Both Dan,+ Sarantis bring up Good points,...

From the poor picture, the splines Do look pretty Pointy,.....
And,...
Frisco,... You Are putting in a 2 pc. rear main seal block,..?? Right,..??

 

[Friscoboater]

Re: Engine Coupler... Need opinions

I have thought about that. The 350 will be from the same year due to that fact. I did not want to have to change alot of things.

 

[jaxnjil]

Re: Engine Coupler... Need opinions

those spline look pretty sharp in the pic.

you can answer your own question by answering this one

is it cheaper to change now, or do you have a good place to work so the cost to pull motor, doing labor yourself and, downtime later would make it worth taking a chance on original?
Personally i would change from your pict. but not a good view.
i have to rent a rough terrain fork lift at $200 an afternoon to pull my motor so that factors into my reasoning

 

[Friscoboater]

Re: Engine Coupler... Need opinions

That is a very good point.

 

[180shabah]

Re: Engine Coupler... Need opinions

Now that all the technical stuff has been covered...

...The boat is a 1981 Glastron and the coupler is original, but looks fine. Do these things fail often?

You answered your own question. 29 years old and original, I wouldn't call that often. Of course the way some peolple approach boat repairs, they get to replace a coupler after just a couple of months. Don't skip the alignment.

 

[Friscoboater]

Re: Engine Coupler... Need opinions

Oh I wont. I am going to order an alignment tool off ebay.