Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 08-09-2015, 10:16   #1
Registered User
 
rastamon's Avatar

Join Date: Nov 2013
Location: Ft. Pierce, Fl.
Boat: Irwin 38 MKII
Posts: 38
Dink won't plane

Hey all,
I recently bought a smaller dink (10') and was going to use an old Honda 8hp 4cycle long shaft I had stored. I used it as a kicker on previous boat. The dink is old RIB. Is the fact the motor is 23" long shaft a contributing factor? Suggestions?


Sent from my iPad using Cruisers Sailing Forum
__________________

rastamon is offline   Reply With Quote
Old 08-09-2015, 10:20   #2
Registered User

Join Date: Sep 2015
Location: Essex, England
Boat: Hartley Tahitian 48
Posts: 322
Re: Dink won't plane

Trim? Maybe move your weight forward when at full throttle to bring it onto plane?.


8HP is a smallish engine as well.
__________________

paulajayne is offline   Reply With Quote
Old 08-09-2015, 10:31   #3
Registered User
 
Stu Jackson's Avatar

Join Date: Jan 2011
Location: Cowichan Bay, BC (Maple Bay Marina)
Posts: 7,092
Re: Dink won't plane

NEI - not enough information .

How heavy are you and/or did you have another person or more on the dinghy?

How much fuel on the dinghy? 6 gallon, 3 gallon?

OLD RIB: What hull material?

What max HP is the dinghy rated for?

Do you have a tiller extender?

Things like that.
__________________
Stu Jackson
Catalina 34 #224 (1986) C34IA Secretary
Cowichan Bay, BC, (Maple Bay Marina) SR/FK, M25, Rocna 10 (22#) (NZ model)
Stu Jackson is offline   Reply With Quote
Old 08-09-2015, 11:07   #4
Registered User
 
rastamon's Avatar

Join Date: Nov 2013
Location: Ft. Pierce, Fl.
Boat: Irwin 38 MKII
Posts: 38
Re: Dink won't plane

I'm 165lbs, let's just say Admiral weighs less🐬 I've tried both ways. Alone and not. Old Boat US dink fiberglass RIB weighs 145lbs. Rather for 10hp. Recommended for 8hp. Carry 3 gal. Fuel ahead of seat no tiller extension.


Sent from my iPad using Cruisers Sailing Forum
rastamon is offline   Reply With Quote
Old 08-09-2015, 11:17   #5
Registered User

Join Date: Feb 2013
Location: Lago de Izabal, Guatemala
Boat: Seafarer36c
Posts: 4,925
Re: Dink won't plane

You need at least a 10hp for that boat. An 8hp will /should plane a 9' with 1 person.
Ecos is offline   Reply With Quote
Old 08-09-2015, 11:18   #6
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 22,324
Re: Dink won't plane

Long shaft is a whole lot more drag, and it may well be propped completely "wrong"
Is the motor revving out, as in motor sounds like it's running fast, just the dink isn't going all that fast? Or is the motor lugging down and won't rev up?
I have no experience with a long shaft motor on a small boat, gut feeling is it will never be "right", but may work.
a64pilot is offline   Reply With Quote
Old 08-09-2015, 11:23   #7
Registered User

Join Date: Jun 2012
Location: Port Aransas, Texas
Boat: 2019 Seawind 1160 Lite (build underway), Prev. 2002 Seawind 1000
Posts: 1,199
Re: Dink won't plane

Hard to believe you are having problem even alone. I have a 10.5 ft Avon lite rib with 8 up two stroke and can plane two adults around 400 lbs at 23 mph wot. It takes leaning weight toward front on takeoff. With single 200 lb person it jumps on plane immediately. Maybe your issue is the extra motor weight and length. Don't know.
sailjumanji is offline   Reply With Quote
Old 08-09-2015, 11:33   #8
Senior Cruiser
 
Cheechako's Avatar

Cruisers Forum Supporter

Join Date: Aug 2006
Location: Skagit City, WA
Posts: 20,664
Re: Dink won't plane

Sounds like you are marginal on HP. The long shaft an issue also. That's a heavy dink .... adding to the problem. The Honda 4 stroke is heavy too. It all adds up.
__________________
"I spent most of my money on Booze, Broads and Boats. The rest I wasted" - Elmore Leonard











Cheechako is offline   Reply With Quote
Old 08-09-2015, 11:38   #9
Registered User
 
S/V Illusion's Avatar

Join Date: Oct 2007
Location: Lakewood Ranch, FLORIDA
Boat: Alden 50, Sarasota, Florida
Posts: 1,866
Re: Dink won't plane

Quote:
Originally Posted by rastamon View Post
Old Boat US dink fiberglass RIB weighs 145lbs.
I think you just answered your own question.
S/V Illusion is offline   Reply With Quote
Old 08-09-2015, 11:52   #10
Moderator
 
a64pilot's Avatar

Cruisers Forum Supporter

Join Date: Oct 2013
Location: Albany Ga.
Boat: Island Packet 38
Posts: 22,324
Re: Dink won't plane

If it was used as a kicker motor for a much larger boat, wouldn't it probably have a very low pitch prop?
a64pilot is offline   Reply With Quote
Old 08-09-2015, 12:04   #11
Registered User

Join Date: Nov 2005
Location: 5 Mile River
Boat: Bristol 41.1 Keep on Dancin'
Posts: 625
Re: Dink won't plane

Might try something like Doelfins to get some lift, but 8hp is a bit light for a 10' RIB, plus it might be a high thrust prop.
keepondancin is offline   Reply With Quote
Old 08-09-2015, 12:47   #12
Senior Cruiser
 
Vasco's Avatar

Cruisers Forum Supporter

Join Date: Apr 2004
Location: Toronto
Boat: CS36Merlin, "La Belle Aurore" Ben393 "Breathless"
Posts: 7,353
Re: Dink won't plane

It's the long shaft. No way you'll get it to plane with that shaft.
__________________
Rick I
Toronto in summer, Bahamas in winter.
http://groups.yahoo.com/group/beneteau393/
Vasco is offline   Reply With Quote
Old 08-09-2015, 12:54   #13
Moderator
 
Jim Cate's Avatar

Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 13,500
Re: Dink won't plane

Have you tried changing the engine tilt angle? With the long shaft, the thrust is well below the WL of the dink, and thus the angle has a larger effect on the attitude of the hull under power.

And fwiw, we used to have a 13 foot soft bottom Zodiac (an old Mk 2) with a long shaft 15 and it planed easily with two up and a load of boat stuff on board.

Jim
__________________
Jim and Ann s/v Insatiable II lying Twofold Bay (Eden) looking for wx to cross to Tasmania
Jim Cate is online now   Reply With Quote
Old 08-09-2015, 13:47   #14
Registered User
 
rastamon's Avatar

Join Date: Nov 2013
Location: Ft. Pierce, Fl.
Boat: Irwin 38 MKII
Posts: 38
Re: Dink won't plane

Hey thanks for all the advice.
It is a "high thrust" engine and is revving up ok. I have adjusted the angles with same results. And figured the extra long shaft might be the problem. If ya see a "for sale or trade" posting, it's probably me!!!
Fair winds ⛵️


Sent from my iPad using Cruisers Sailing Forum
rastamon is offline   Reply With Quote
Old 08-09-2015, 14:23   #15
Moderator
 
Pete7's Avatar

Cruisers Forum Supporter

Join Date: Aug 2009
Location: Solent, England
Boat: Moody 31
Posts: 10,630
Images: 14
Re: Dink won't plane

Sorry to say this but you have completely the wrong engine. Mercury and Mariner have a sailmate engine with a high trust prop and lower gearing designed to move a small motorboat or yacht. I suspect you have the Honda equivalent.

Measure the transom from top to bottom of the V. It is probably 15-16" so you need a short shaft engine. 21-22" require standard shaft length. Ditch the Honda and buy one the right shaft length. then mount so the ventilation plate is 1" above the bottom of the V as a start point. Suggest a 2 stoke engine as weight seems a bit of a problem. If you can find a Merc Seapro engine they have extra stainless steel parts inside which will help, something like the old X10 engine.

Pete
__________________

Pete7 is offline   Reply With Quote
Reply

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
Getting my Dink to Plane chris95040 Auxiliary Equipment & Dinghy 16 18-08-2014 10:06
SSB - where can my ground plane be? esper General Sailing Forum 1 25-03-2009 10:25
Fossett's Plane Wreckage Found Ex-Calif Off Topic Forum 14 07-10-2008 06:05
Flare Gun, flares and smoke flare on a plane? sgtPluck Health, Safety & Related Gear 3 27-08-2008 18:16
Bringing an inflatable PFD on a plane disco192 Health, Safety & Related Gear 6 03-07-2008 17:29



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 18:21.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2018, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.