Comparing OMC 9.9 or 9.5 to 15 (horsepower) 2 Stroke engines only

[jbjennings]

Re: Comparing OMC 9.9 or 9.5 to 15 (horsepower) 2 Stroke engines only

The weight of the motor is not the only thing to consider as far as stress on the transom. You also have to consider the torque on the transom and the leverage created by the prop being low and the connection to the boat being up high. I think a 15hp pushing a moose carcasse would pull the transom apart at the corners in a short time if you actually ran it at 3/4 to full throttle-----making the 15hp useless since you couldn't use it without ruining the boat. I agree, a 6-8hp would be better. I have an aluminum welding machine that I'd have to put on that boat! Still, 15hp is probably too much. I should have looked at your boat before. However, I'd still have the 15 over the 9.9.
JMO,
JBJ

 

[Frank Acampora]

Re: Comparing OMC 9.9 or 9.5 to 15 (horsepower) 2 Stroke engines only



Bah humbug! A couple of pieces of sheet aluminum, a couple of corner gussets, some stainless bolts, and you are ready to go with the 15.

 

[FL2AK]

Re: Comparing OMC 9.9 or 9.5 to 15 (horsepower) 2 Stroke engines only

Bah humbug! A couple of pieces of sheet aluminum, a couple of corner gussets, some stainless bolts, and you are ready to go with the 15.

That's actually a rather common mod that man folks up here do tot he 19' Grumman Freighter Square Stern, only they use tubing to brace the raised transom board to the gunwales about 3' fwd of the stern.

By the way, nice Chrysler 55! That was the engine on my dad's first bass boat (a Terry fiber glass boat). Fished my first bass tournament in front of a Chrysler 55. (2nd grade 1979-ish.)

 

[FL2AK]

Re: Comparing OMC 9.9 or 9.5 to 15 (horsepower) 2 Stroke engines only

A short shaft Evinrude/Johnson (1973-1993) 9.9/15 with manual start weighs in at 72 lbs. Add 5 lbs for the electric starter (77lbs), not including the battery. A long shaft will add 5 more lbs, 77 or 82 lbs, depending if it has electric start or not. These are the lightest 9.9/15 HP motors, especially when compared to the newer 4 stroke motors avalable today.

The 9.9 is a great engine. The 15 is an even better one, it will have more power throughout the RPM range due to more air and fuel being available at any given time, and the modifications OMC made to the 15 (tuned exhaust pipe and leaf valve shims). The one area where the 9.9 shines over the 15 though is trolling at low speeds. The 9.9 idle and run a little better at low speeds than the 15's.

I appreciate the comments, especially that of the trolling speed performance. I hadn't considered it, and I didnt know that bit about these engines, but that's another reason for me to continue looking for a 9.9. Low troll/idle speed was something I loved about my little '69 4HP. (May it rest in peace-in my garage.)

 

[64osby]

Re: Comparing OMC 9.9 or 9.5 to 15 (horsepower) 2 Stroke engines only

My current engine is a 2013 Yamaha 4 stroke 4 hp (the boat is rated for 5),....

I have a good bit of experience with all 3 on the same boat... I must note that the boat was rated for a 25, ...

Jim sorry to raise your hackles, didn't see the 5hp first time through. Not trying to be irresponsible.

So is the boat rated at 5 or 25? or does it depend on the model, year or length.

 

[FL2AK]

Re: Comparing OMC 9.9 or 9.5 to 15 (horsepower) 2 Stroke engines only

Jim sorry to raise your hackles, didn't see the 5hp first time through. Not trying to be irresponsible.

So is the boat rated at 5 or 25? or does it depend on the model, year or length.

All of the Grumman Square Sterns (to my knowledge) be it the wider Sport Boat or the Sq. Stern Canoes are rated for 5 hp regardless of year. (After the 1970's, the metal is thinner and the rated load carrying capacity is considerably less, but the hp rating is the same.)

 

[jasoutside]

Re: Comparing OMC 9.9 or 9.5 to 15 (horsepower) 2 Stroke engines only

There are some places I go that require a portage. (up and over a hill half a mile).

Just thought I'd chip in here....

I have an Evinrude 15 LS with the electric start. She's a great motor! But, she's kinda heavy moving from the boat to the garage and back again. Not horrible, just kinda heavy.

Rugged terrain and long hikes with that motor would be a real drag.

 

[JimS123]

Re: Comparing OMC 9.9 or 9.5 to 15 (horsepower) 2 Stroke engines only

All of the Grumman Square Sterns (to my knowledge) be it the wider Sport Boat or the Sq. Stern Canoes are rated for 5 hp regardless of year. (After the 1970's, the metal is thinner and the rated load carrying capacity is considerably less, but the hp rating is the same.)

You didn't quote the load capacity yet. Is it rated for a person plus a half ton of moose?

 

[FL2AK]

Re: Comparing OMC 9.9 or 9.5 to 15 (horsepower) 2 Stroke engines only

Just thought I'd chip in here....

I have an Evinrude 15 LS with the electric start. She's a great motor! But, she's kinda heavy moving from the boat to the garage and back again. Not horrible, just kinda heavy.

Rugged terrain and long hikes with that motor would be a real drag.

I suspect as much, and I don't plan on making a habit of it. lol. Portaging a 120 lb aluminum canoe isn't very enticing, either. This is the main reason I'm so displeased with the 4 stroke Yamaha 4hp I bought. It's only about 10 lbs lighter than a 2 stroke 9.9/15 and less than half the power. So you can see why I want to change.

 

[FL2AK]

Re: Comparing OMC 9.9 or 9.5 to 15 (horsepower) 2 Stroke engines only

You didn't quote the load capacity yet. Is it rated for a person plus a half ton of moose?

1000 pounds total. Person(s), gear, and cargo. The way this works is you load the boat considering the water conditions by watching your freeboard. I don't carry a scale with me and weigh game meat as I load it. Just load the boat until you think you can't give up any more freeboard and then stop. Leaving gear on the shore and coming back for it later, or the next day, is not uncommon.

 

[nwcove]

Re: Comparing OMC 9.9 or 9.5 to 15 (horsepower) 2 Stroke engines only

You know, the more I think about your comment here, the more sense it makes. If the 9.9 and 15 are the same weight (and someoen mentioned 120-ish pounds??? I didn't think they were that heavy.), then, if the 8 is significantly lighter, I'd trade the 2 HP for the weight. There are some places I go that require a portage. (up and over a hill half a mile). I'd trade 2 hp for 30-40 pounds, especially given I'm already dragging a 120lb boat. Do you happen to know the weight nan 8 hp OMC?

the 6/7.5/8 hp motors from the early to mid 1980's weigh in at close to 56 lbs. ( some models even have or will accept a 12v charging kit)

 

[FL2AK]

Re: Comparing OMC 9.9 or 9.5 to 15 (horsepower) 2 Stroke engines only

the 6/7.5/8 hp motors from the early to mid 1980's weigh in at close to 56 lbs. ( some models even have or will accept a 12v charging kit)

Speaking of the 7.5 and 9-1/2 hp (the low profile) outboards...I took my 69 Evinrude 4hp into a shop today where they kind of have a niche market on these older 2 stroke OMC's. They had a 9-1/2 Johnson low profile laying on the floor that someone abandoned, but when I asked if I could buy it and if it was slavageable the guy said probably but you don't want one because parts are getting too hard to find (especially up here). And on that note, he offered to sell me a 1975 9.9 that another person had abandoned. Think I might be buying that.