Mercury 15hp vrs 20hp outboard

I have a new Achilles 310AL with the Tohatsu 15hp electric start and it is more engine than my dingy needs. Look at the price difference mine and Mercury... They are made in same plant.

 

I have a West marine 11.5 ft hypalon weighing 160 LBS with a 15 hp Mercury this combo gives me plenty of speed and planes very quickly.

 

With 2 adults it gets a plane quickly and no issues. With 4 adults I do no attempt to plane. Our previous dinghy was pull start and not a big deal but for a few extra bucks it's now push-button and I added a USB & 12volt outlet into the top of the battery box. So, in short get the electric start and you won't regret it.

 

We would have been fine with a 15hp, but when we had family over, I was happy to have the 20hp. Something very satisfying getting on plane with 4 adults and 2 kids. 15hp wouldn't have done that!

 

My boat has the hydraulic lift platform.12 ft is the the max boat that will fit on the platform.Total weight of my dingy is 270 LBS.

 

Blueone, a good friend in the marina got the Highfield last year. It is a nice set up and he runs the 20hp Merc.
I only have a small 10hp Merc and I am looking for a 20hp this season, but where we are located, we travel pretty far in the dink(s) and will spend all day (8 to 9 hours) running around the bay and bars.
If it were me and the dink is rated for it, I would always go for the more hp. If / when you add a couple of adults the extra power will be handy.

 

Opps, mistake in my previous response. I am looking to upgrade to a 15hp this season not a 20hp. My dink is only rated up to 15hp.

 

We have had the Highfield 290 for 3 years now we started with a 9.9 mercury which worked OK but with the short hull length it was sometimes difficult to get two people on plane quickly especially in rougher water last year I switched to the new 15HP EFI with the cool center mounted tiller it works perfect I top out at 20 mph WOT with one person haven't checked it with two but it can't be much different, I would recommend the 20 HP for the 310 like you said the weight is the same, I would go with the electric start if I had to do it over again.
Rick

 

From my experience, it would be cheaper to buy the 20HP now, rather than "modify" the 15HP to be a 20HP later. One way to check is to compare parts lists (and part numbers) between the two engines. See what things are different and the costs associated with each. Account for labor either by paying someone or taking into account how much your time is worth.

You might consider Smart Tabs, if needed. They would make a VERY noticeable difference in hole shot - regardless of the engine. Not expensive, either.

One thing I've learned over the years... NO ONE in the history of boating has ever said "Shoot, I should've bought the smaller engine".

 

Oversized and under-utilized rather than undersized and over-utilized ??? I'm very happy with my 15hp and when it's just me, I have scared myself a couple of times...lol

 

Agree with all of this, but go with the 20hp, and I doubt you will need the Smart Tabs. Not sure you need electric start, as the EFI starts easier than any carb engine. BTW, have you looked at the Suzuki? I have had one for 4 years now, simply an outstanding motor. They got into the EFI in the smaller motors early on, and it shows. Outstanding piece of machinery.

 

The Tohatsu 9.9, 15 and 20 are identical engines. The difference is in the ECU and an intake restrictor. A new replacement ECU can be had for around $800. I plan to upgrade my 9.9 to 20 this winter.

Tohatsu makes the small Mercury engines, so I would bet there is a similar upgrade path. All that said, it's more cost effective to buy the bigger engine up front, than to retrofit it later.

 

The 15hp will NOT plane with 4 adults, just tried it last weekend, get the 20hp. That being said the new tiller handle with shifter is nice, I'm very happy with mine

 

That new Mercury looks really nice. It might be enough to convince me to trade up from my 2 stroke Evinrude. The biggest reason I have a 2 stroke is for the weight savings over a 4 stroke. At 99 lbs that difference is really close now. EFI? Yes please - not looking forward to another carburetor rebuild. The adjustable tiller looks fantastic.