Should I upgrade to a bigger motor?

[Sea Dobie]

Hi all,

I have a 17' Harbercraft with a 60hp Mercury 4S. I am thinking about trading the motor in for a new 90hp Mercury 4s. The 60hp is basically new -as is the boat. My question is will the larger motor be too much for trolling? The 60 trolls really nice. However, I want a bigger motor to pull a skier, tube, etc. Also, my current WOT fully loaded speed is 30mph with the 60. What kind of top end speed could I expect out of a 90? What kind of trade in value would I have with a basically new motor (less than 10hrs)?

Finally, my last question is should I even upgrade or just leave it alone?

http://www.wamail.net/%7Ejcarr/1725_Adventurer_boat.jpg

Thanks,

Jason

[hookumhi]

probably cheaper to get all new boat . the bigger motor is very expensive and trade in value is probably not gonna be good. just my .02

[fireguy]

Sea Dobie,
I did a very simillar upgrade to my Northriver 18' mariner when I bought it the boat had a yamaha 60. The motor only had 10 hrs on it, but it made the boat seem really under powered. I ended up getting an yamaha 90 I feel it is the perfect boat now. I looked all over to get a good trade-in the guys at Auburn sports and maine gave me the best deal for a new motor. :applause:

[ICHTHYDEMON]

For what you're going to gain with a bigger engine,I'd probably leave it alone. It takes a sizeable jump in HP to amount to much. I'd say going up 30HP will probably give you another 3-4 mph.

I've read more than once,that it takes about 10hp to gain 1mph.

If you tinkered with the prop as well,you might get another 1mph or so.

[mitch]

For what you're going to gain with a bigger engine,I'd probably leave it alone. It takes a sizeable jump in HP to amount to much. I'd say going up 30HP will probably give you another 3-4 mph.

I've read more than once,that it takes about 10hp to gain 1mph.
.


I believe this is a conditional quote. The faster you go it takes that much more to go that much faster. Getting to 45 is pretty linear. Getting past 45 starts getting less return for the HP. I'll bet you can get close to 45 with the 90, maybe a bit more. Its only a 17 ft boat so increasing the HP will have more of an effect then jumping 30 HP on a larger boat. The big question will be is it worth the math to upgrade after the fact. Doing so is a lot more expensive than doing it initially.

[dog]

Sea Dobie,

This is my experience. I have a 1996 17' Sylvan Super Select which is a lot like your boat. I bought it with a new Yamaha 50 HP 4 stroke. It would do okay getting on a plane with 1-2 guys but struggled with 3-4. Had to move people to the front etc. etc. Any altitude killed getting on a plane period. However once on a plane my boat would go 32 mph on the river with 2 people.

Then, i upgraded to a2002 Honda 90 HP 4 stroke. It gets on a plane WAY better now obviously even with 3-4 guys and not having to move them around. I did move my batteries from the rear to the front which helped too. Believe it or not I still have a hard time getting on a plane at Paulina with 4 guys on the boat(altitutde 6300 feet). My speed on the river at WOT has only increased to 37 mph with the 90HP so Ichthyderm is right on on his statement.

As to trolling, when I fish B10(7-11 days a year) I exclusively troll with the 90 instead of my Honda 9.9 which I also have on the boat(love to steer and throttle at the wheel especially in the crowds). And we seem to catch our share of fish. Sometimes i am going a little faster and sometimes a little slower than the other bazillion boats. My motor idles at 750 rpm but I usually troll there at around 900 rpm. I also always use the 90 to chase fish off the anchor-both salmon and sturgeon.

However, for little coastal rivers like the siletz etc. or lake trolling I am not sure if the 90 trolls slow enough because I don't normally do that so i can't help you there. I have seen some people do it but a lot of times you will see them with buckets out or trolling plates which can be done but those have their own issues.

All the $$ questions you have can only be answered by a boat/motor dealer /salesman who has the motor to trade you. You might be able to get a pretty good deal on a new 2007 motor right now.

Oh yes, I also noticed the 90 burned way more fuel than the 50. However we troll all day at B10(some long days), make all the runs to the areas we want( sometimes from Warrenton to B10, to church/bridge/ to oregon side , back to chinook, IlWaco etc. etc.(guys always got to find the hot bite) and the most gas we ever used in one day was 13 gallons. Usually for a day there it is in the 9-11 gallons range.

Hope this helps and Good luck!!!!

[north0f60]

hi Jason,

I have an 18' Robinson which is basically the same 12 degree hull as your Harbercraft Adventurer. I have a Yamaha F90 and currently a 15 pitch prop. I get about 35-36 at WOT, lightly loaded with 2 adults and 2 kids. I'm going to try a 17 or 19 prop this summer. Hoping for about 38-39 ...
I'm at about 2300 ft ASL so that's about a 2 MPH penalty vs. sea level.

Hauke

[flyingd]

I have a 74' 18' Starcraft with a 90hp johnson 2 stroke. Idle is around 700 +-. I can not get down to a good troll speed. Always on the edge of too fast. Meaning I am at 2.3 or so and can't get down to 1.5 or 1.8. I tried a different prop, a really shallow prop pitch, but that didn't work at all, dropped maybe .2 mph and dropped 15 mph off the top end. yuck

[Gr8waves]

Hi all,

I have a 17' Harbercraft with a 60hp Mercury 4S. I am thinking about trading the motor in for a new 90hp Mercury 4s. The 60hp is basically new -as is the boat. My question is will the larger motor be too much for trolling? The 60 trolls really nice. However, I want a bigger motor to pull a skier, tube, etc. Also, my current WOT fully loaded speed is 30mph with the 60. What kind of top end speed could I expect out of a 90? What kind of trade in value would I have with a basically new motor (less than 10hrs)?

Finally, my last question is should I even upgrade or just leave it alone?

http://www.wamail.net/%7Ejcarr/1725_Adventurer_boat.jpg

Thanks,

Jason

According to the emails our spam filter catches, everyone either needs or wants a bigger motor!

[Chrome Bumper]

If you just want more slow trolling and a a little more top end get one of these attachments for your motor:

















http://www.ifish.net/gallery/data/500/great_white_attacks_motor.jpg

[Sea Dobie]

Thanks everyone for the advice and information. I am going to call a couple of dealers and see what they can do for me. If I can't get a decent deal I'll most likely bag the idea. I am just hoping a dealer may have a new or slightly used 90 with a warranty.

[eharris]

Did you do this or not? I was kind of thinking along the same lines on my 17' Alumaweld. I have heard some talk of just switching props but I don't know much (if anything) about the specifics. I would be curious to know what information you got from dealers on a trade-in and whether you thought it was worth it. One problem I have is that my boat is maxed out at 60 according to the manufacturers plate. PM me if you get this and don't mind sharing info.

Evan

[BARCHASER]

I bought a 2005 18' NR Seahawk on sale that had a Yam 90 4strk. I didnt want to spend the extra bucks to upgrade to the 115, since I had a kid in college at the time. I was afraid the 90 would be a little underpowered but for me its worked out well. It has plenty of power for what I do.

Sea Dobie,
I did a very simillar upgrade to my Northriver 18' mariner when I bought it the boat had a yamaha 60. The motor only had 10 hrs on it, but it made the boat seem really under powered. I ended up getting an yamaha 90 I feel it is the perfect boat now. I looked all over to get a good trade-in the guys at Auburn sports and maine gave me the best deal for a new motor. :applause:

[SOL]

I bought a HewesCraft 179 SeaRunner with a 75hp Honda. It was a DOG! 31mph WOT, cruised at about 20mph.

15hrs later...

Upgraded for a 115hp Honda. What a difference, 39mph WOT, cruising at 27mph.

The biggest difference was at cruise, with the 75hp I was constantly running 4800-5000RPMs. With the 115hp I cruise around 3800-4000RPMs. Better fuel economy and less strain on the motor.

[trap50]

I don't know how heavy your boat is. I have a 19' Harbercraft (2000) it weighs 860# dry weight. I have a 115 yahama wot is about 44mph gps with 2.

[HOGTIDE]

.............should you have another slice of pizza?

.........................should you get bigger tires on your 4X4??

....................................should you date a girl with bigger, er, uh ...brown eyes???


..........Of Course, you 'should' get a BIGGER MOTOR!!!!

[Cliff D.]

The problem with C/B's trolling attachment is it puts down a hot bite, but i will admit i've never had a seal problem while using one !! :D

[AlseaAssassin]

My old man his the pretty much the exact same boat other than it's 18 feet long and a 90 4-stroke is just about perfect. I would think it would be plenty of power for your application. I think his boat does around 38 mph I believe? I would think yours would do around 40? I'll ask him a few questions for ya.