8 foot quicksilver inflatable with 15hp

[praetorian]

I'm looking at getting an inflatable for the back of my boat. There aren't that many available right now, but there are 2 that seem good:<br /><br />1. 2000 Quicksilver 8' with 15hp merc 2stroke (~$2000 canadian)<br /><br />2 1996 zodiac 8' with 5hp Honda 4 stroke ($2750 canadian)<br /><br />I'm leaning towards the quicksilver because of cost, and it's closer to home to get it. I like more power (I always like more power), but reading the zodiac and quicksilver sites, these size boats are rated for ~4hp. Is the 15hp overkill, and is that bad in any way?<br /><br />Any advice would be appreciated, thanks!

 

[cobra 3.0]

Re: 8 foot quicksilver inflatable with 15hp

If it's rated for 4 hp and you are putting a 15, that's way too much power! Stick with the recommended hp ratings on a boat. The 15 would probably rip up your boat on the first run.

 

[praetorian]

Re: 8 foot quicksilver inflatable with 15hp

I see people with 10hp motors on dinghy's like this all the time, not sure what the advantage is?

 

[crazy charlie]

Re: 8 foot quicksilver inflatable with 15hp

Anything rated for a 10 will usually accept a 15 with no overpower problem.The 10 and 15s are usually the same motor tweaked.I have a 9.9 on my 10 ft zodiac and it flys with 2 people.Charlie

 

[Das Boot]

Re: 8 foot quicksilver inflatable with 15hp

I have two Zodiacs one at 16 feet 40 hp and one at 13 feet 30hp, they are equally as fast in a GPS test, i would not try to "overpower" a Zodiac<br />follow the manufactures guidlines............

 

[Jdeagro]

Re: 8 foot quicksilver inflatable with 15hp

We have supplied and Tested many Zodiac inflatables and ribs. Everything from a 3.5hp on a 8.0" to 240HP Hamlton diesel on a 24' (Navy boat).<br />I invented Smart Tabs origionaly for a 10' soft bottom Zodiac, with a 9.9 two stroke. The 15'HP was the same motor except for a throttle linkage part. This means that the low end torque is the same as well. HP is developed in the higher RPM range. <br /><br />The Hoda is going to be much quiter, but harder to get on plane. The 15HP will probably no weigh too much more, and will plane easier. In either case the comfortable cruising speed on this boat with not too much of a chop, will be about 8 to 10 MPH, although the boat will get to about 15 MPH with the Honda and 20 with the 15. In either case both getting on plane and holding it at 8 to 10 MPH will be nearly impossible. You will need to be going at least 14 to 15 MPH with two people.<br /><br />The bow rise will be horrible at slow speeds with either motor. Top speed will be a problem as the boat will be difficult to handle. Frankly they handle like crap. Most people will put a hydrofoil on the motor, but other than some minor assistance with planing they can cause more handling problems than benefits.<br /><br />As for the choice, the motors will weigh about the same, so moving things arroound will be equal. The added HP will be nice if you try to cruise with a larger load. If the 15 runs nice, I would lean that way too. If you get water in a four stroke engine it's a goner. A two stroke can be run with some extra oil for a few minutes and your good to go.<br />Fuel economy on a motor of that size is a none issue.<br /><br />Check into Smart Tabs if you buy one and realy want to have a nice clean, smooth running tender.

 

[cobra 3.0]

Re: 8 foot quicksilver inflatable with 15hp

Guys this is getting off topic. The question is should he use a 15 on a boat rated for a 4 or 5. (Mercury makes the "Roll up series" rated for a 4hp on the model 200 or 5hp for the model 240.)<br /><br /> http://www.mercurymarine.com/mercury_240_roll-up <br /><br />Praetorian, Mercury's "Air Deck series" model 310 is rated for a 15. The transom is far stronger and can take the weight and thrust the 15 produces. "Dingy's like this" is what can take a 10 or 15.<br /><br /> http://www.mercurymarine.com/mercury_310_airdeck

 

[praetorian]

Re: 8 foot quicksilver inflatable with 15hp

Thanks NautiJohn,<br /><br />That was exactly the advice I was looking for. I didn't know about getting a 4 stroke wet! Let's face it, this thing is going to be carried on the back of my boat (w/davits).<br /><br />Do I need to take the motor off the dinghy when I tilt it onto my boat? Forget the weight, I'm wondering if this 15hp Merc 2stroke will leak if it's on it's side?<br /><br />Thanks for the advice, I'm going to look into the smart tabs right now!

 

[Boatin Bob]

Re: 8 foot quicksilver inflatable with 15hp

I used to have a Quicksilver model 300, it was 9'9", smallest one that was rated for a 15hp, I had a 15 Mariner on it and used the Weaver davits to put it on the swim platform. The motor didn't leak in the upright position, dealer told me it was designed not to. Mine weighed about 100lbs but it had the 3 peice wood floor, looks like today's version weighs a little less. That thing took off like stink but the bow rose up pretty high (NautiJohn, don't read this next part) so I put a Stingray hydro foil on it, Canadian Tire was clearing them out for $10. What a difference it made, bow didn't go as high and it was on plane instantly. Taught both of my boys to waterski behind it. However I would not put a 15 on it if it's not rated for one, have seen them over powered and it tears the transom right off.

 

[Jdeagro]

Re: 8 foot quicksilver inflatable with 15hp

Boatin Bob:<br />My Heart is broken!!!!<br /><br />Just kidding - I used a hydrofoil first but it was not enough and everytime I took the engine off to bring it into the cockpit I banged my shins. <br /><br />To Praetorian;<br /><br />The Smart Tabs will reduce the stress on the hull because the resitance to plane will be much less. If the boat is not a RIB this will be a benefit, as the transoms can get pulled apart.

 

[Snowdrggn]

Re: 8 foot quicksilver inflatable with 15hp

I have a Z131 (wood floor Zodiac,rated 10hp), 15hp Evinrude (same weight as OMC 9.9, running 10x11 Pirhana prop), Smart Tabs. The total weight of the boat is about 160lbs. The boat has been in use over 10 years (carefully cared for, and stored inside when not in use), frequently towed adults on kneeboards, and other things. It shows no signs of distress in the transom area from being over powered ( I do keep a constant eye on it!). At minimal loading the boat will do 32mph (GPS) with the engine 6940-6950 rpm (rev limiter). I can say that it is a wee bit of a wild ride at that pace! I would advise that whatever you decide to go with that you consider engine weight in the hp range that you choose. I have had a 15hp Honda on this boat and the increased weight destroyed the handling and performance of the boat (72lbs OMC vs 110lbs? Honda). The big advatage of the setup I have is that with the Smart Tabs and the engine that I have is that I can back the engine down to about 40% throttle, stay on plane, and burn less fuel than I do running my 8hp Evinrude on it. The Smart Tabs control bow rise (big issue on small inflatables!), and drop minimum planing speed WAAAYYYY down.