Will 6HP be enough?

[reelfishin]

I have an older Gamefisher 12" trihull boat, the bare hull weighs about 400 lbs or so. I want to use it for backbay crabbing and some freshwater river fishing. I have the chance to get a 6HP Mercury 2 stroke, I believe the motor is a 1999 or 2000 model. It's basically new, I know the guy that bought it and he may have run it only 1 or 2 times before he passed away. He got ill right after buying the motor and never used it, it sat in his basement eversince. It is in mint condition and was well stored. I was wondering if it would be enough to power my 12 boat? The Gamefisher is not much more than a jon boat and has a 10HP max rating.
I weigh in at 275 lbs, and most of the time have a buddy with me that is close to my weight and size. I like the boat and the design since it will allow me to get into some tight places that I can't get with my larger boats. I have already tried the boat out with a 40lb thrust trolling motor, it does OK but I wouldn't want to get it in any serious current.
Does anyone have one of those 6HP Mercs?
Also, What would you offer someone with one? His wife asked me to make here an offer and I have no idea what the value on that would be? I looked around locally, but all the new motors I see are 4 strokes and in the $1500 range. What would be a fair price for a mint used motor?

I also have a much older 9.5 HP Evinrude Sportwin that runs good, but I like idea of having a newer maybe more reliable motor when out in the current of the river.

 

[tashasdaddy]

Re: Will 6HP be enough?

if that sportwin has good compression, put a carb kit, point, condenser, coils, wire, impeller in it for $150. and you will have a decent boat. the 6 is going to be sluggish with the bluntness of the trihull, 400lbs of boat 350lbs people, 40lbs gas, then gear and beer. you are pushing 900 lbs.

nada boats, list average retail on a 2000 6hp at $550. you are going to have to do and impeller and carb kit on it.

also is the shaft length of both motor right for the boat?

 

[steelespike]

Re: Will 6HP be enough?

I think you missed a little on the weight T D like 500 lbs people.But I'm just nit picking.
But even at something like 6 or 7 hundred lbs lbs I would think the boat is over its max.

 

[reelfishin]

Re: Will 6HP be enough?

Teh shaft length is perfect on either motor, the 6 hp is basically brand new, I doubt if it's seen more than 15 or 20 minutes of run time. It's sitting in a heated/airconditioned garage and the cylinders have been fogged with oil. I packed it away when he got sick back in 2001, it's not moved since. I agree on the value, but have been watching this size motor online and have seen a few even a lot older and in far worse shape go off for nearly double that. I can't figure out why someong would pay that much when a new motor can be had for around $1500. I gave $300 for the Sportwin 4 years ago but it's a freshwater only run motor with 140 psi compression and a new impeller just installed. The points are new as are the plugs. I just hate to rely on an older motor. If the motor fails, I am pretty screwed out in the river. There's a strong current and a dead motor means anchor up and wait for a tow or head out into the bay in a hurry. I've tried a 3HP motor and it pushes me ok, but it's slow. A little more would be great. What concerns me it freeboard at the rear with the 9.5 vs the lighter 6hp. The 6hp is almost half the weight of the older 9.5hp. I have looked at new 6 to 10 hp motors, (stuck with no more than a 10 due to local hp limits in most lakes here). I don't want the added weight of the newer 4 strokes or do I want the maintenance. I can buy a new Merc 6hp for $1500 here.
Someone also told me that the 6Hp was the same basic engine as a 9.9? Could I upgrade this motor? I am far more interested if I can make this a 9.9 of larger.

 

[reelfishin]

Re: Will 6HP be enough?

At my size, just about any boat is over it's max, there's not much I can do about it. I can't take a 20' boat into the lakes and streams and a larger boat can't ride down back trails in the bed of my truck to get to the good fishing spots.
I had a larger 14' boat but that was too heavy and didn't carry much more weight, it just took more people to get it unstuck when it got stuck in the shallows. The 12' Gamefisher's CG plate is too faded to see, but I think these were rated at about 435 with 3 people. I guess they meant three little kids with that rating. I had another one of these a few years ago and the total weight with persons, motor and gear was 570 lbs. This one is actually a bit larger, it's about 6" wider and nearly 12" longer, even thought they call it a Gamefisher 12.
I've been using a 10' aluminum boat with a 275lb rating with a 3hp on it, it gets in places where nothing else can but I wouldn't take it in the river. The Sears trihull has nearly a foot of freeboard with both of us, a battery, trolling motor, a 6 HP outboard, and 3 gallons of gas. Plus tackle. It does just fine and is super stable.
At my size the options are limited, they just never made a small boat that is rated for a guy my size. Any boat that is rated to carry the weight won't go were it needs to go. I tried one of those 10' plastic two man pontoon boats, it was rated at 900 lbs, but didn't last, it got sunbaked after a year and the seats collapsed into the plastic. It was also way to heavy to carry in and out of the truck.

 

[tashasdaddy]

Re: Will 6HP be enough?

if i remember correctly the 9.9 and the 15 are the ones that are almost idenitcal. i think the cover are even interchangable. not the 6 and 9.9. seems like there was the discussion of buying the 15, and disgusing it as a 9.9 to get into the lakes.

 

[reelfishin]

Re: Will 6HP be enough?

I know that's the case with the Johnnyrudes but I haven't had a Merc to compare to. Maybe it's the 9.8 or 8.8 they mean instead? The 6HP is the larger frame motor, it looks like the same cover and all and is a twin cylinder. I had an older 9.9 Yamaha built Mercury back in the late 80's that was the same as the 15 then, I built it up as a 15 but left the 9.9 labels. This looks more like a Nissan or Tohatsu motor. I was at a local dealer the other day and they had new 6HP motors for $1499 and 9.9HP motors for $1899. They were all Tohatsu and Nissan motors. They said they were all 2004 leftovers they had bought someplace.
All of their 9.9 motors were long shaft and while the 6hp's were all 15". I like how light that 6 is, it's half the weight of my 9.5Hp Sportwin.

I am only considering the 6HP since I know where it's been and that I know its still new and unused. The only time it was used was a right out of the box test run and it never got used again.
I just don't want to be in the same situation that I am in now with a severly underpowered boat that won't get on plane. The boat won't hold any more motor than a 10HP and by looking at the transom design, that's probably pushing it a bit. The transom is only fiberglass with a piece of wood which looks like a piece of 5/4 decking board glassed in at the top which doesn't even go all the way across to each side. The boat is like new and was stored indoors since 1973 too. The 9.5 Evinrude is actually a better match time wise for it.
I would guess that the 6 hp would probably do fine with just me, but will most likely struggle with two people. This boat will mostly get used with an electric motor, but having the gas for the larger lakes and river would be nice, especially if it's new and reliable. I was also thinking about one of those Briggs Stratton 5hp motors, but they don't look all that strong either.
I like the no waterpump and low maintenance of the B/S motor though.

 

[billybones]

Re: Will 6HP be enough?

I have a 12ft mirrocraft from 69 with a 76 7.5 hp. Between my son and me and the lode we are at the max. 575. it will still plane fine and still do a decent 25mph. 24inch fish and bigger are a pain though... no place to hide ;-)

 

[reelfishin]

Re: Will 6HP be enough?

My old 14' boat was a Mirror Craft V hull, that did great with a 20HP but top speed was about 25 with two people tackle and gear. That boat was light but about a foot wider and the v hull helped a lot. This trihull is super stable though, I could probably stand on the gunwale and not tip this thing over. I had a 14' version with just the rounded front hull and that did good with a 5hp but would never get on plane. I never cared about that boat since it was only used in small ponds. I only tried the gas motor out once on that. That was one of those 5HP Eskin motors from Sears. This hull has more of a V up front with only small outer hulls. I would think that it will be close to a v hull at low speed. The outer hulls are almost completely out of the water with me at the rear of the boat.

 

[steelespike]

Re: Will 6HP be enough?

I believe there is a Evinrude/Johnson 8 that is close to the 6 in weight.
within a few pounds.But it would have to be used.
I think Billybones must have hit the wrong key 25 from a 7.5 with a load
would be impossible.Empty would be around 18 to 20 mph.

 

[TOHATSU GURU]

Re: Will 6HP be enough?

The Mercury 6, twin cylinder, is not a Tohatsu. That's a Mercury built model and if memory serves it is a detuned 8....Might even be a de-tuned 9.9. It's a decent little engine, except I would be careful with that throttle grip/shift.

 

[jauguston]

Re: Will 6HP be enough?

I have the 1985 Evinrude 8 that Steelspike speaks of. It weights 56 lbs plus the remote tank. I have it on a 12' Crestliner aluminum Jon Boat that weights 140 lbs. I weigh 240 lbs. The other day I was testing it on the lake and had my MinnKota Power Drive 40 on the bow and a group 27 battery for it near the bow. My GPS showed best of 17.8 mph. I have a 4.5 that is the same family engine and it would do 7 mph.

Jim

 

[BillP]

Re: Will 6HP be enough?

Your on the edge with 6hp for performance...even 1hp more is noticable in these sizes on boats like that. The 9.9 will do better, especially when two people are aboard. I personally would be more concerned with reliability on the "new" merc than he "old" OMC. Older parts that are out fishing are better than newer parts sitting in a shop for repair.


b.

 

[reelfishin]

Re: Will 6HP be enough?

So what is the general concensus here? If any of you had the chance to grab basically a new 2000 model 6HP for $550, would you do it?
If not I can still use the 9.5HP, but I hate to pass up a good deal on a good motor. Even if I don't use it on this boat. I'd just rather it were a bit larger motor. If it were a 9.9, I would have never hesitated.

What would it take to up the 6hp to an 8hp or maybe more? Carb change?

Were these US built motors? Back in the late 80's, they were Yamaha built, at least I know the 8, 9.9 and 15 were, I had a 9.9 converted to a 15 then, that one was badged Mariner, but at that time there was only a Mercury and a Yamaha dealer near by and I often bought parts from the Yamaha dealer for it.

 

[BillP]

Re: Will 6HP be enough?

Power wise the 6 is going to be iffy getting the boat on a plane with one person and my estimate says no way it will plane two. The 9.9 will plane with two.

bp

 

[reelfishin]

Re: Will 6HP be enough?

Can I convert the 6hp to a larger HP motor? The way I see it is that for the price, it still may be worth it. The motor is still new, and a new motor will cost me no less than $1500 for what I need. Even if I needed to upgrade this a bit it may still pay to grab this motor? Or not?
I looked for 2 years before I found the 9.5 HP Evinrude that I have now and paid $300 for that and even though it's in running condition, it is still 35+ years old.
Was the 2000 6 HP 2 stroke an american made motor or still an import?

 

[ondarvr]

Re: Will 6HP be enough?

I have an older 6hp Evinrude, a newer 8hp Merc and an older 9.9 Evinrude, there is a big noticable difference in what these motors will do on a 12 foot boat. What the 9.9 will do with ease, the 6 can't come close to doing and the 9.9 has more thrust than the 8. Use the 9.9 and put the $550.00 in the bank, don't buy something you don't really need.

 

[reelfishin]

Re: Will 6HP be enough?

My other motor is a 9 1/2 HP Sportwin, do they compare to the more modern 9.9HP motors?
I was only considering the 6 since the price was right and it won't eat much to just keep as a spare. I do wish it were a newer 9.9 though. If I could find a later model 9.9 I'd buy it instead.

I guess I keep comparing or figuring that the 6hp would do more than it really would. I have one of those Tanaka made 3hp air cooled motors now on a similar aluminum boat and it moves two guys and gear pretty well, but its not on plane. The fiberglass Gamefisher will probably push easier, although it's wider and a bit longer, it won't sit so low in the water and it does cut the water some up front.
The aluminum jon boat moves at what I would say is a very fast walking pace or better, with the little 3hp on that boat it creates a huge wake in it's path. The fiberglass trihull moves faster than the aluminum boat does with only a 40lb/thrust trolling motor and a group 24 battery. That boat came to me with a 7.5HP ted williams motor on it, also air cooled, that motor barely would move that boat, even empty, while the 3hp did much better and actually moves the heavier and larger fiberglass boat better than it does the aluminum flat bottom jon boat.

The part that gets me with the 9 1/2 hp Evinrude is the small prop? The prop on the 2000 Merc 6HP is nearly double the size? The prop on the 9 1/2 HP is not through the hub exaust and looks very similar to the prop on the Ted Williams or the Tanaka 3HP. The 6 HP prop looks more like a normal prop to me, full fan style blades instead of thin, swirl shaped blades.
I guess I just have to try the 9 1/2HP to see what it does. It just looks to tiny to do much, the 6hp looks like more of a motor, it's physically larger and sits higher on the transom. The 9 1/2hp just looks so short and squat compared to the Mercury 6.

 

[kenmyfam]

Re: Will 6HP be enough?

6hp to 10 hp power noticeable difference will be huge. especially with more load aboard.
Look at it this way. A 10hp is a 66% increase in power from the 6hp.

 

[reelfishin]

Re: Will 6HP be enough?

My biggest concern isn't speed or getting on plane, its simply being able to move against the current. The 3hp does the trick but barely and only at full power. The 3Hp won't move at all against the current in the river. If the 6HP will run and pull me upstream, it will be fine. I think that simple fact that the prop is so much larger will make a huge difference, in other words the 6HP has to have more torque. If I run the 9.5, I'll need to carry more gas, the motor weighs more and that alone may detract from the added hp. The 6hp will be better on fuel than the 9.5 too. I think I'll grab that motor either way, if it's not enough, I still have the 9.5, and I'll either keep it for a spare or pass the deal on to someone who can use it.
I watched a buddy of mine this morning with a 16' aluminum starcraft with an older 6HP Johnson, a trolling motor and two group 27 batteries onboard, along with a dozen or so bushels of crabs come in at the dock, he's been using that boat to pull in crab pots for years. he and a helper, the batteries, boat and cargo have to be over 1600lbs, the hull is an 84" beam and a deep V hull. That boat has to have more drag than my little 12' boat and he's running in the back bays and tidal creeks and it makes good headway with only the 6hp.
He has an older 20HP but won't put it on since the 6hp runs so much cheaper. He only travels a few miles, but it's in all turbulent water. If the Merc 6HP is anything close to that, I think it will be fine.