What level of performance will my 14ft get with 40hp?

[Mark42]

I have a '62 MFG Niagra Deluxe 14ft runabout and have ordered a rebuilt '92 40hp Johnson for it. The plate says 50hp max, boat weighs in at 530lbs. I will be using it mostly on lakes, but occassionally on the bays on Long Island NY (Noyack bay, Sag Harbor bay, Shelter Island bay).<br /><br />I am wondering how well this boat will handle the water in nice weather and what speeds can be expected (crusing and top). I have not had this boat in the water since I bought it. So any experience with a boat this size would be helpful.<br /><br />Thanks,<br />Mark42

 

[Jdeagro]

Re: What level of performance will my 14ft get with 40hp?

Need more information about the boat. ie: hul material, hull design and shape etc.

 

[JB]

Re: What level of performance will my 14ft get with 40hp?

Hi, Mark.<br /><br />Assuming that your rig weighs about 1,000# on the water, has a fairly flat bottom at the stern, is ideally rigged and propped and correctly balanced:<br /><br />Theoretical WOT would be between 38 and 40 mph.<br /><br />Good luck.

 

[Fweep]

Re: What level of performance will my 14ft get with 40hp?

Mark,<br /><br />Most of the outboard makers have performance data sheets on their sites.<br />I have a 14'5" Scout modified V hull that is rated for 50HP. I have a Yamaha 50 and the data sheet lists their test with a 500 pound boat 10 gal gas and 2 people with a 40HP will do the following. (I looked at the Johnson site and they tested with a pontoon boat). Your boat motor combo may be close to this test data.<br /><br />RPM MPH GPH MPG Db<br />1000 2.8 0.9 3.29 65<br />2000 5.6 1.5 3.73 72<br />3000 7.6 2.7 2.81 82<br />4000 23.9 3.5 6.83 87<br />5000 32.35 4.3 7.52 91<br />5200 34.55 5.3 6.58 93

 

[Mark42]

Re: What level of performance will my 14ft get with 40hp?

Ooops! I thought everyone knew what a '62 MFG Niagra was because everyone at one time or another owned mine! LOL!<br /><br />I did read the Johnson writeup on the 40hp but was dissapointed that it was on a pontoon boat. Not very close to my application of that motor.<br /><br />Its a fiberglass lapstrake design V hull runabout. It does have a fairly flat hull back by the transom. <br /><br />Funny thing is that old brochures show this little boat pulling two water skiers! I wonder how accurate that picture is??? Those old sales brochure specs list max hp as 45, but my plate lists it at 50. My guess is that as 45hp motors were dropped in favor of the 50's, they changed the spec.<br /><br />Thanks to all for the info. Here is the sales brochure photo:<br /><br />

 

[catfish1]

Re: What level of performance will my 14ft get with 40hp?

i'm guessing max speed at 30mph. i have a 14ft bayliner with a fresh 50hp evinrude that does about 35mph, depending on water conditions.<br />if you dont have a tachometer on it, get one! speed doesnt matter, its the rpm that matters. if you ever ask questions about the boat here, the first thing thats going to be asked is whats your wot rpm.

 

[ED21]

Re: What level of performance will my 14ft get with 40hp?

Way back when we had a Johnson 40 on a similar size boat. We actually did pull 2 skiers at times.<br />Of course as kids we didn't weigh much & getting up was a bit of a struggle. Once we were up we could kick off a ski. Experienced skiers could do it, but single learners could still have trouble getting up alone. As I recall the boat had a top speed of about 27 mph. We never had a tach.

 

[majornflfan]

Re: What level of performance will my 14ft get with 40hp?

Hey Mark, <br /> I was just wondering where you found that sales brochure photo? Hopefully looking to find one for my '79 rig. Hope its as much fun for you as it looks, have a blast!<br /> Tom

 

[Mark42]

Re: What level of performance will my 14ft get with 40hp?

Hi majornflfan!<br /><br />If you have a MFG boat check out this website:<br />www.mfgboats.com<br /><br />Mark

 

[Lark40]

Re: What level of performance will my 14ft get with 40hp?

My family had an Evinrude/MFG dealership in the the 1960's. So, I have driven that boat with 35 and 40 hp OMC outboards.<br /><br />I'd guess 30-32 mph top speed with one person.