Your thoughts on a new Engine

Food for thought on the HP of repowering from a Force to whatever.

After 1200+ hours on my '96 Force 120 we were very happy with it except for the smell when idling or cruising, and you get good at the math of 50:1 after a while!

Our boat with the 120HP maxed out at 64kph SOG with a half-tank of fuel and 2 guys in calm water and no current or wind, as shown on a GPS receiver.
This was with prop testing and a well tuned motor.

While snooping around a few years ago I found a solid deal on a '94 Merc 115 2 stroke that was oil injected so had it mounted and sold the Force.

The slight drop in HP (115 vs 120) worried me since we use the boat for watersports as well as fishing, but the mechanic told me that the Force motors were optimistically rated.

The Merc has repeatedly hit 77kph SOG in the same conditions as the Force was tested.

The increase in top speed shocked me!
So, I whipped out my Physics texts and reviewed how to compare HP.
It turns out that to increase the speed of my boat from 64kph to 77kph requires an ACTUAL HP increase of 30%.
So, the Force 120 was performing as if it were a Merc 80!!!

The point is that if you are moving up from a Force you might</u> want to consider that they may</u> actually produce 30% less power than labelled, as compared</u> to other brands, and so you may</u> not need to increase the HP by as much as you think.

Hmmmmmmmmmm!
 
Thanks for the info marula! I have another question for you and everyone else, I've never had trim tabs would they help me get better fuel economy?
 
I would say trim tabs are worth every penny! Besides it wears on you riding leaned over to one side all the time too!!
 
The best engine that I would go with is 200hp e-tec 2 stroke. Great on fuel 5-6 per hour and no oil changes. This is the most powerful engine that I have come across and will kick butt out of the hole and top speed over any 4 stroke...........

just my two cents.................GB
 
quote:Originally posted by gradyboat

The best engine that I would go with is 200hp e-tec 2 stroke. Great on fuel 5-6 per hour and no oil changes. This is the most powerful engine that I have come across and will kick butt out of the hole and top speed over any 4 stroke...........

just my two cents.................GB
Click to expand...

X2 on the E-TEC got 3 seasons with close to 300hrs on my 175 now and not a hickup. These engines are leaps and bounds ahead of anything else out there in all catrgories.

IMG_1021-1.jpg
 
If I was to re power my boat I would probably go with an Evinrude E-tec.
I think if you compare numbers the new motors are better on fuel than the 4 strokes. I have an older model a 200 which burns around 8 gallons an hour at 4200 rpm. Attached is a video comparing a 150 e-tec to a Yamaha 150 http://www.youtube.com/watch?v=_-7I00cZUE0Just my 2 cents worth
 
I don’t think trim tabs add to fuel economy. When I use mine at WOT they slow me down a small amount. That said they can get you on plane faster and keep you on plane at a slower speed. All good things that’s for sure. I use them to balance the boat and they work very well for that. Back to topic, can anyone attest to the longevity of the four strokes? I see lots of old two strokes still running, anybody out there with and old four stroke? I was talking with the guys at the machine shop and they seemed to think the two strokes were still better engines. They did like the Suzuki four strokes to work on and rebuild. They said the crank and bearings were conventional and that made it easy to rebuild.
 
A suggestion to be careful with the generic statement that "4 strokes are quieter that 2's". The 115 merc 4 is actually louder than the 115 merc opti at idle and low revs, but the 4 is quieter at high revs. This, plus the wieght factor and proven nature of the opti's is why we still use opti's on our tour boats. We also REALLY REALLY like the 10 rpm digital throttle control for fishing which we can't get with the Evinrude that we looked at this season when we repowered two boats.
 
i have a 07 opti 115. my boat is 06/ 542 campion
guests on the boat comment on how quiet the engine is.
with the boat fully loaded with 4 adaults i was able to cruise at 30 mph 4400 rpm. at wop with a 19 pitch prop i get 40 mph at 5200 rpm with 2 adaults..
at half a tank of gas the boat jumps out of the hole and seems to perform alot better with the lesser weight.
ive been happy with the opti fuel consumpion as long as i stay under the 4000 rpm mark.
i know a guy with a 150 yammy /542. he can get 50 mph.
if i were to buy again id go with the 150 yammy it would turn the boat into a hot rod....

selfish-1-1.jpg
 
Well flytyer what have you found in your research and which way are you leaning.

GB
 
The great thing about two stroke is that there are no oil changes!!! As far as other maintenance goes there are very little difference.
 
love the input guys,as I prepare to purchase a new boat i will keep all this in mind. I will say I love the two strokes,as for the smell,well it is something I have become accustomed to in 30 years of fishing {not always catching}.My opinion is that the two stroke has more longevity than the 4's,just go to your local dealer and ask what kind of hours would be expected from each.Simply a two stroke has less moving parts therefore less to go wrong.As long as they get the 2 stroke oil they need they will last. For oil injected motors it is my experience that after several years or thousand hours you may want to replace the injection system or change to pre mix to be safe.All in all Dirt bikes and boat motors I love two strokes&gt; longevity,low maintenance and power. Ps you don't buy a hemi for fuel economy! Also I am lookin at these 2o foot or so welded aluminums with extended transom 18 degree v hull any input? Thanks!!
 
Well flytyer I have a 2006 90 E-TEC on a 16 ft. double eagle with 300 hrs on it. This engine runs flawless,just like it did out of the crate. The power\weight ratio is awesome,and its great on fuel. I tend to run the boat at 3600- 3800rpm clipping along at 28mph on a running plane.Fuel economy always is related to how much throttle your giving the engine,which is directly related to how much weight you have to push.Some food for thought.Good luck with your search.
 
CS is right 20 is bang on.............. Take care if you go any deeper then 20 you will end up cutting in swells which can be a pain if you are tracking in a specific direction as well as you will have to be more on and off the throttle in the swells.

If you are not going to be in swells then the deeper V the better............ but lets face it your on this site so you play in the swells!!!!!!

GB
 
I've been reading this post with alot of interest and I can say now I've got some good info for all.
I run a 25' Grady with twin 4 stroke suzuki's...
Now they work for what we do because not only do those Zukes push the boat 28mph while only burning 16gph combined...and it's a heavy boat with full fuel...200gallons if we fill it.
The best part though is the fact that we can troll on the mains...swapping them out every hours or so to keep the hours the same.
Now that eliminates the need for a kicker and a TR-1 system, etc.
The motors burn about the same as a 9.9 at idle and we actually have to speed them up to troll.
Ya...you have to change oil every hundred hours or so but it gives me a good reason to check the bottom of the boat, transducer, props etc.
Now, with this being said...If I was to run a single with a kicker....I might think of something like an e-tec or opti....
Remember one thing though when your running those new 2 strokes...they burn expensive oil each day.
just my 2 bits

www.coastwidesportsfishing.com
 
Exactly as said in the above post...twin 250 yami's on ours. Idle down real nice and amazingly quiet. THe odd day when you get a real good tailwind pushing while trolling she might be going a little bit fast...but that happens handful of times a year...plus still seem to get some fish nailing it even harder that way. Burn barely any gas as well...relative to the days amount burnt it is nearly a write off.

www.serengetifishingcharters.com
 
Well guy's this has certainly been a informative thread, from reading and researching I guess if I had the money to repower my trophy I'd go E-tec or opti. I had no Idea that the opti is such a good motor. I'm with Jimbo on the whole 2s thing.

cheers
 
Things sure have improved since I had to keep swapping magnetos to keep my old Mercs running!!! ( you young guys-- Google "outboard magneto" if you dont know what I am talking about!!:D

I am running a 2008 115 Merc 4X on my 20ft tin boat. Its great, most of the time I troll on the main rather than the kicker. But it is not as quiet as a Yammi when at speed. Other than that-- its great on gas and cheaper to buy.




20ft Alumaweld Intruder
 
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