1985 60 hp prop question

[coolguy147]

Re: 1985 60 hp prop question

You got that right. Years ago I didn't tighten the set screw on my straight drive inboard, a couple a of weeks later when I put it in reverse the shaft backed right out of the coupling and stopped against the rudder.

Lol I could imagine the look on your face........

 

[coolguy147]

Re: 1985 60 hp prop question

I have the motor on the 4th hole up. Runs fast I might drop it a hole because it keeps gripping and slipping in and out. With a full tank it's pretty good but running super light it will slip. Pulls out of the hole fast.

 

[steelespike]

Re: 1985 60 hp prop question

If I recall right your running a ss prop, should grip well.There are SS props that a good aluminum prop can match. Now is the time to get us your wot rpm and gps speed.
Do you have power trim? Perhaps you can move more weight to the stern.
If you lower it just enough to minimize the venting it might even improve speed.

 

[coolguy147]

Re: 1985 60 hp prop question

If I recall right your running a ss prop, should grip well.There are SS props that a good aluminum prop can match. Now is the time to get us your wot rpm and gps speed.
Do you have power trim? Perhaps you can move more weight to the stern.
If you lower it just enough to minimize the venting it might even improve speed.

Yup, I'm using a SS prop. I don't have a TACH D: I might be able to get the gps speed.

 

[coolguy147]

Re: 1985 60 hp prop question

Ran the motor today. It definitely needs to be put down a hole. Too much venting and when I needed back up, it would not lol!

 

[steelespike]

Re: 1985 60 hp prop question

While your motor may be too high I wouldn't think it would bother reverse.
Through hub props sometimes have a divergence (?)ring that helps keep the exhaust from fouling the prop in reverse.
Maybe yours is missing.
An induction tach like the tinytach will work on your motor and almost any other.Can be hand held or installed.
Some cells have a gps app.

 

[steelespike]

Re: 1985 60 hp prop question

While your motor may be too high I wouldn't think it would bother reverse.
Through hub props sometimes have a divergence (?)ring that helps keep the exhaust from fouling the prop in reverse.
Maybe yours is missing.
An induction tach like the tinytach will work on your motor and almost any other.Can be hand held or installed.
Some cells have a gps app.
Your prop diameter is a little small, those available here seem to be 11 3/4".as the smallest.
A larger diameter might resist venting better.
Without a wot rpm and gps speed we can't tell if your prop is right.
The GPS speed will help a little, better than no numbers.

 

[coolguy147]

Re: 1985 60 hp prop question

While your motor may be too high I wouldn't think it would bother reverse.
Through hub props sometimes have a divergence (?)ring that helps keep the exhaust from fouling the prop in reverse.
Maybe yours is missing.
An induction tach like the tinytach will work on your motor and almost any other.Can be hand held or installed.
Some cells have a gps app.
Your prop diameter is a little small, those available here seem to be 11 3/4".as the smallest.
A larger diameter might resist venting better.
Without a wot rpm and gps speed we can't tell if your prop is right.
The GPS speed will help a little, better than no numbers.

The motor needs to go down a hole either way because it vents too much at or near WOT.

This is my first through hub exhaust so i'm a newbie on how it works? Divergence ring? I don't think it's on there.

I have a tiny tach but it stopped working out of the blue D: Might have to send it in.

It seems like they don't manufacturer my prop anymore.

I'll see if my friend can come, and bring his Iphone. Know any good free GPS programs for the iphone?

 

[coolguy147]

Re: 1985 60 hp prop question

Clocked it at 33-34mph today with it at the 3rd hole up and 3rd hole out. Had two people, battery, and 6 gallons of gas in the boat. I figure i could get 36mph with a light load?

 

[coolguy147]

Re: 1985 60 hp prop question

2 cylinder Merc 40 went to 35 in 84-85.
My info says The 70 hp went to 60 in 84-85.
The 50 hp 4 cylinder did go to 45 in 86.
inline 6 was 90-115 82-86 and only 115 in 87,88.
The Evinrude 45 cube 2 cylinder motors no obvious changes through the " key years.
3 cyl. 60,70 hp has a displacement increase after 85. 55 & 60 prior to 89 are 49.7 cubes.
As you might imagine There are surely some motors that we're simply tweaked to make the rating.
It appears these changes came between 84 -86.
I think the change may have been agreed upon be members of the outboard association and not necessarily acted on at a specific date. And as I understand it Force never did change to a prop rating.

My 60hp is two cylinders. Not three.

 

[steelespike]

Re: 1985 60 hp prop question

My 60hp is two cylinders. Not three.

My info indicates last year for the 2 cyl. 60 was 85.My guess is it is powerhead rated.
I think you would need a careful gps speed to tell the difference.
At 34mph guessing 10% slip your rpm is about 5100 the 60hp is rated at 5500.
It appears your pretty well propped.

 

[coolguy147]

Re: 1985 60 hp prop question

My info indicates last year for the 2 cyl. 60 was 85.My guess is it is powerhead rated.
I think you would need a careful gps speed to tell the difference.
At 34mph guessing 10% slip your rpm is about 5100 the 60hp is rated at 5500.
It appears your pretty well propped.

I think it's revving way more than 5100. The second trim hole might allow the prop to get its full bite.

 

[steelespike]

Re: 1985 60 hp prop question

The slip guess could be way off. Just using an approximate typical number go with your speed.

 

[coolguy147]

Re: 1985 60 hp prop question

The slip guess could be way off. Just using an approximate typical number go with your speed.

Maybe. Having it in the 2nd hole will tell...unless i still need to lower the engine to the 2nd hole up?

 

[phillnjack2]

Re: 1985 60 hp prop question

your engine is crank rated.
the 60 was re-designated 55hp and that was being kind.
at the prop youl be getting 50hp if its a good strong engine, the 87 50hp is exactly the same as yours.

Now i run a 13x19 omc sst prop with the convergence ring,no slip terrific acceleration and very decent top end.
Im pushing way over 40mph with mine but i have the 3 cylinder 60hp from 1995 so i have a bigger cubic capacity engine anyway.
your engine will weigh less though, by about 60 pounds if you dont have trim n tilt.
You can get your prop cupped if it isnt already and that will help big time with cavitation, and give better top end and pull away.
ive gone to the top hole and i dont lose any bite on tight turns or running flat out.
I run at maximum revs, maybe even a touch over.
you need to get a tacho rigged up, ive just done the electrics on mine and im hoping the tacho is now working.
once river level goes down a touch or it stops raining, ill give it a blast and see what revs i am getting.


phill

 

[coolguy147]

Re: 1985 60 hp prop question

your engine is crank rated.
the 60 was re-designated 55hp and that was being kind.
at the prop youl be getting 50hp if its a good strong engine, the 87 50hp is exactly the same as yours.

Now i run a 13x19 omc sst prop with the convergence ring,no slip terrific acceleration and very decent top end.
Im pushing way over 40mph with mine but i have the 3 cylinder 60hp from 1995 so i have a bigger cubic capacity engine anyway.
your engine will weigh less though, by about 60 pounds if you dont have trim n tilt.
You can get your prop cupped if it isnt already and that will help big time with cavitation, and give better top end and pull away.
ive gone to the top hole and i dont lose any bite on tight turns or running flat out.
I run at maximum revs, maybe even a touch over.
you need to get a tacho rigged up, ive just done the electrics on mine and im hoping the tacho is now working.
once river level goes down a touch or it stops raining, ill give it a blast and see what revs i am getting.


phill

I really need to see where my RPMs are at. If i'm revving to high then i would cup it and raise it up a hole again to retry it at the highest height and 3rd hole out.

 

[coolguy147]

Re: 1985 60 hp prop question

Looking back at it, my prop has a cast-in diverging ring on it. 2nd performed well. Didn't have any real problems with venting. The bow didn't seem to plow but the boat seems flatter now. Cruising is nice.