Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 08-07-2018, 23:26   #1
Registered User
 
Sojourner's Avatar

Join Date: Oct 2017
Location: On the boat!
Boat: SY Wake: 53' Amel Super Maramu
Posts: 861
Dinghy trim problems / motor size issue?

Ciao y'all, I have a few stupid questions about my dinghy.... I've been sailing a good while but this is my first owned boat, and so my first own dinghy that came with her, and I was hoping for some general dinghy advice....

The dink is about 3.something meters, on the small side. The engine is a Mercury 15 hp. With that engine we can plane all together (me + 2 small women) but usually 3 larger people won't plane. But no matter what, including by myself, I have to sit so far forward that I hold the tiller with two fingers half the time to keep the nose down, especially when not planing, and the mound of wake behind the engine is huge at nonplaning to the point where I'm afraid water can (and maybe has) splooshed against the housing, esp when slowing down. Is the motor mismatched in size (too heavy) for the boat? Or should I be adjusting the trim to raise the prop some? It also seems to be eating gas pretty fast (but I have little frame of reference....how long should a 15lt gas tank last for a 15hp Merc? Last but not least, last time out, we got sloshed pretty good from the back, to where the engine sound changed briefly, and not much later the idle (which ran perfectly at the lowest setting always before) now threatens to die at idle unless turned up to highest idle, and even then I'm needing to goose the throttle a bit to keep her alive.

Any thoughts on any of these subjects would be most appreciated!
__________________
3 cats, 3 queers, endless wake, endless love!
https://www.facebook.com/anendlesswake/
https://anendlesswake.com/
Sojourner is offline   Reply With Quote
Old 08-07-2018, 23:54   #2
Registered User
 
Sardean's Avatar

Join Date: Dec 2014
Location: Brisbane, Qld, Australia
Boat: Fastback 43 catamaran
Posts: 235
Re: Dinghy trim problems / motor size issue?

Quote:
Originally Posted by Sojourner View Post
Ciao y'all, I have a few stupid questions about my dinghy.... I've been sailing a good while but this is my first owned boat, and so my first own dinghy that came with her, and I was hoping for some general dinghy advice....

The dink is about 3.something meters, on the small side. The engine is a Mercury 15 hp. With that engine we can plane all together (me + 2 small women) but usually 3 larger people won't plane. But no matter what, including by myself, I have to sit so far forward that I hold the tiller with two fingers half the time to keep the nose down, especially when not planing, and the mound of wake behind the engine is huge at nonplaning to the point where I'm afraid water can (and maybe has) splooshed against the housing, esp when slowing down. Is the motor mismatched in size (too heavy) for the boat? Or should I be adjusting the trim to raise the prop some? It also seems to be eating gas pretty fast (but I have little frame of reference....how long should a 15lt gas tank last for a 15hp Merc? Last but not least, last time out, we got sloshed pretty good from the back, to where the engine sound changed briefly, and not much later the idle (which ran perfectly at the lowest setting always before) now threatens to die at idle unless turned up to highest idle, and even then I'm needing to goose the throttle a bit to keep her alive.

Any thoughts on any of these subjects would be most appreciated!
I have a 15hp mercury on my 10ft polycraft. It is very sensitive to trim adjustment. Adjust your trim so motor is down as far as it goes. Be aware that if that adjustment puts nose down to far boat may be unstable when on the plane, if so bring it up one notch untill its right. I sometimes adjust mine to suit rough conditions, bow down when punching into waves. Bow up for following sea.
Sardean is offline   Reply With Quote
Old 09-07-2018, 00:14   #3
Registered User

Cruisers Forum Supporter

Join Date: May 2011
Location: Miami Florida
Boat: Ellis Flybridge 28
Posts: 3,692
Re: Dinghy trim problems / motor size issue?

This is a very common problem. The easiest solution is trim tabs. Fixed tabs or spring loaded tabs are fine. They don’t need to be hydraulic or electric. You just need to get some planing surface aft of the transom to lift the stern.

Fins attached to the engine will work as well but trim tabs will add less drag.
__________________
Retired from Hopkins-Carter Marine Supplies
HopCar is offline   Reply With Quote
Reply

Tags
dinghy, motor, size

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Most manageable size outboard motor for dinghy epiic Auxiliary Equipment & Dinghy 79 22-02-2020 19:04
Dinghy Motor Size Captain Randy Liveaboard's Forum 72 26-08-2018 20:52
Want To Buy: Need Bennett Trim Tab Motor Hunky Dory General Classifieds (no boats) 0 11-02-2018 19:02
Kaiser Gale Force 34 Trim Issue holtjp General Sailing Forum 21 14-07-2015 19:47
Defever leaning to port...trim tab issue? CAcruiser Powered Boats 63 22-07-2014 13:22

Advertise Here


All times are GMT -7. The time now is 11:00.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2020, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.