Would a 15 HP upgrade help my situation?

A year ago here on TinBoats, I "blogged" the entire process of modding of my bare bones Mirrocraft 14' mod vee, and a year later I can tell you I love the setup...it's been great.

If there's one slight wrinkle, it's probably the Nissan 9.8 outboard. It runs like butter, starts second pull after being stored all winter, no gripes about the motor itself, it's picture-perfect. But it doesn't have *quite* enough zing to get the boat up on plane. Top speed with one person is about 16 MPH. With two people, it's more like 12. I'd love to have just enough extra oomph to level her out at full speed rather than dragging tail.

My question, would upgrading to a 15 HP give me enough added kick to do the job? I don't think I could go bigger than a 15 because of my back (having tried manually tilting a 20HP out of the water, I know it's more than I'd want to do).

To put it another way, if I'm close to planing with the 9.8, but no cigar, is a 15 likely to get me there?

My old boat was a 13 foot valco with a 10 horse, it would not plane with 2 guys, I bought an old 18 horse and put it on. I thought I was the king of the world, it would plane with 2 guys, a cooler, loaded with fishing gear and fuel. We never checked the speed but guessed 18 to 20 mph. Pound for pound that boat caught more fish than any other boat in the county.

The extra horses will certainly help


I would look more towards a 18, 20 or 25 hp - get a two stroke so it is light If you can pull


A 15 hp Merc ProKicker is 135lbs


a 2 stroke Yama 25 hp short shaft is 105 lbs


So get the biggest lightest thing you can find - you can always run at less throttle !

I too would strongly reccomend a 25hp 2 stroke. The performance will amaze you compared to the 9.8 and will easily plane and run 20+mph with 3 people in it.

I would recommend a 25 hp 2 stroke with a manual tilt assist. You will go like the wind and still have a happy back.

Thanks guys. How do these manual tilt assist things work? Some sort of pneumatic piston?

[url=https://www.tinboats.net/forum/viewtopic.php?p=356380#p356380 said:

dsuden » Thu Jun 19, 2014 8:29 pm[/url]"]Thanks guys. How do these manual tilt assist things work? Some sort of pneumatic piston?

Click to expand...

Leverage

Ah, worth a thousand words! Thanks much.

There's also aftermarket tilt and trim units...cmc pt35, Bobs,minnnkota...

Now after,(if) you quit giggling when running a 25 h.p. on your boat,(should you chose to.) ,remember to fish a little too. \/

dsuden,

IF it was me, I'd look for and find a 1962-70, 18-25HP, OMC 2-stroke that weighs NOT much more than your current 9.8, as those old OB are CHEAP to buy, LONG-lived, TOUGHER than "a ten cent steak", SIMPLE to do routine maintenance on and you need NOT be a mechanic to keep them in top condition.
(My electric start FDE-12, 18 horse Johnson weighs 83 pounds & a 25HP weighs about 10# more.)

yours, satx

That's a nice boat you have, certainly worthy of a fantastic motor. If it were me I would have no qualms about purchasing a new 25hp electric start with trim tilt. It won't be cheap but that boat is worthy of it!

I'm new to this too, but from that picture, it looks like your cav plate is 4-6 inches below the bottom of the boat.

Have you tried shimming the motor up to see if that helps you? A jack plate may help.

Have you tried different trim angles? Have you tested your rpm at WOT? Maybe all you need is a slightly higher-pitch prop.

If you really are close to planing, those might be your answer...


Just a thought.

Just purchased a 2005 25hp Yamaha 2-stroke and it is one great outboard. It will get your boat up on plane with 3 people.

Congrats on the new (to you) motor.. =D>

dsuden,

IF you want a NEWER or 4-CYCLE outboard, you might want to look at one of the 20-25 HP Hondas.

yours, satx

I think for the size of the boat you have it would benefit greatly from a 25 hp outboard. The boat I have has a rating of 25 hp and with a 25 it the performance is amazing. A 15 will help some but the boat will not reach the level of performance it is capable of doing. Fuel consumption on the Yamaha 25 2-stroke is very good also. Once up on plane you are able to throttle back to less than half throttle and plane for a long time. I noticed that from owning both a 15 hp and 25 hp Yamaha 2-strokes that the fuel consumption is similar on the 25 hp Yamaha when throttling back and planing the same speeds that the 15 hp Yamaha did. I am glad I made the choice of going larger than a 15. The G3 1448PF and the 25 Yamaha 2-stroke is a great match and looking at your boat it think you will get similar performance.

I had a 1989 Evinrude 15hp on a 14' Gregor. Was a great motor and planed that boat in a hurry and I weigh 275lbs! I'd look for one of those. Plus they are very light weght.