Boat not Planing

[borraro]

Everyone, I recently picked up a used boat package. I am running a 2005 Lund 14DLX Adventure (14' aluminum boat with a floor, 2 batteries, etc. decently heavy). The boat is only rated for a max 25HP outboard. I am running a 2005 Johnson 25 HP 2-stroke outboard. The problem I am having when I went, my front end goes up in the air and won't come back down (even with someone sitting in the front) and am therefore only going 15 km/hr because I am plowing against my hull. I am assuming this is a prop issue and need to adjust my pitch. The current prop is a 3-blade 10x13. I did some checks on my motor just to see if there was a problem there. Compression test turned out about 120 on each cylinder (2 cylinder). Tested plugs, coils, etc and it is running off both cylinders. Motor sounds awesome, starts fine, never stalled out, idles, etc. I am stuck here, I don't want to go buy props and that not work. For my engine I was thinking about going to another 3 blade but 10.5x11? I tried my buddies 10x15 because he had one on his 30 HP and it didnt help. Thanks!

 

[steelespike]

Is the motor trimmed down prop closer to the boat?
Decently heavy is a little vague. Dry weight is 390,2 batteries 100 lbs fuel 40 lbs,you 200 lbs ,motor about 125.
Your all up weight 855.? Your 13" pitch is too much.I checked 3 Evinrude tests Each over 900 lbs all up weight.
These used 12" props Speeds were 31,27,and 26. rpm ranged 5600 to 6000. the 26 mph time to plane was 3.5 seconds.
These are Etec 25 hp motors they are bound to out perform your 25 But you should be within these numbers.
I do think your 13 should work I'm sure it would struggle.I think there is a motor issue there some where.
To errer on the low side I think an 11" pitch may work but will be masking some issue.

 

[Sea Rider]

You could be testing a prop that has already "issues" be on it's way to have a totally spun hub. Personally before embarking on a new prop would perform a slip hub test, if found ok maximizing prop from there. If found caputt your problems starts as assume you haven't tached that engine before, so don't know if props revs inside min-max wot rpm range to buy same new if performed good or maximize from there to suit you boating needs.

From experience it's nearly impossible to dial best prop from factory delivered one on a second intent as you don't know how much more rpm the engine will rev by going +, - 1 pitch, so generally is dialed on the third intent unless extremely lucky blindly dialing on second intent.

Need to install an induction tach to play with prop pitches all you want. Testing different props without a tach is no bueno, a costly experimentation that could ruin your engine. Best engine/transom height, well trimmed with weight evenly distributed does wonders for any given boat.

Happy Boating

 

[littlerayray]

Welcome aboard you need a tach and give us the numbers and make sure your trimmed all the way also look into moving your batteries to the bow