What size OB motor do you use?

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Lanealoha
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What size OB motor do you use?

Hey all.  I'm interested in learning what size motors people use for their tinders.  I'm interested in having some power for scooting around but being that I'll mount it to a bracket on the stern rails I dont want it to be too heavy.  I'm thinking min 6hp but would really like an 8hp  but I'm concerned on the weight issue with that type of mounting.  Thoughts?

Dave

David Lane
S/V Grace
88' Catalina 36'
Oxnard, Ca
 

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pkeyser
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It all depends. If you don't have an outboard lift on the transom and plan to mount the engine on the rail by hand- a little 2-3 HP 4 stroke is about the max one could comfortably handle- and that's not going power any tender to scooting speed. We have a 3.3HP 4 stroke and it probably weighs 45+/-pounds and is best mounted on the rail with a lift. If you could find a reliable old stroke, 3HP would be an easy to handle feather weight, but still not offer fast propulsion. To move at a planing speed, you would likely need at least a 9.9HP. Now your in the 90 lb range. All depends on your tender too. 

Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B

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KevinLenard
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We started with a 9 hp 2 stroke which could get a soft or hard bottomed dinghy up on plane and it was JUST BARELY light enough for me to handle without risk of dropping it into the water over the stern, but it would have been difficult to manouever up onto the stern rail (we tow the dinghy everywhere).  For more pushing power (a concern I've had as twice we've had engine trouble in no wind that require me to push the C36 from behind for an hour), I switched up to the Mercury 9.9 hp 'Kicker' high thrust.  The propeller is larger and slower, but it still gets us up on plane on the new hard bottom 9 foot tender without too much difficulty.  About 13-17 mph is top speed. The new motoer IS A BEAST at 113 lbs (electric start with motorized tilt) and I cannot manage it without the use of the mast crane at the club.  The stainless steel guys I spoke with said they can build both a lift that will handle it alone, or even davits that will haul the dinghy WITH this motor up safely.  Just thicker SS and blocks. 

Kevin Lenard
"Firefly"
'91 C-36 Mk. "1.5" Tall Rig, Fin Keel, Hull #1120, Universal M-35 original (not "A" or "B")
CBYC, Scarborough, Lake Ontario, Canada

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Catboat Willy
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Dave;
 We use a 2 stroke Tohatsu 3.5 HP outboard to push a nine foot Hard Bottom Inflatable (HBI) around the harbor. We also use a Garhauer outboard motor crane to mount this light engine on the Catalina's rear pulpit rail and dinghy. It is certainly not the fastest dinghy in the harbor but, at 38 pounds, it may be one of the most manageable.
First, I think horse power of the required engine has much to do as to what type of dinghy you wish to push. An HBI or solid bottom type tender will be usually be easier to push through the water than a soft bottom inflatable and thus, requires less horse power to so.
Our 9 foot Achilles HBI is rated for up to a 9 HP, but moving and mounting a 100 pound 4 stroke engine would seem more trouble than the extra speed  is worth, even utilizing the motor crane.
The new 4 stroke engines are even heavier than the older (now illigal) 2 stroke engines and, of course, once you go over 6 HP, you will start into two cylinder models and again, add more weight.
Just for kicks: a five gallon pail of water weighs about 42 pounds. Fill one up and try moving that around the transom area to get an idea of what it would be like at double that weight.
So to conclude, I'd say weight is an important consideration and perhaps one that can be placed above speed.

Pictured below is how we rinse the salt water out of our little engine.
YMMV
Bill

Bill Dolan 1990 Catalina C-36 MKI - Hull #1041  'Williwaw'
Std. Rig, Walk Through, Wing Keel
M35, Oberdorfer Conversion,
Home Waters; Charlotte  Harbor & The Gulf Islands of Florida
'You are never out of work if you own a boat'

 

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TippingPoint
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Bill,

Just curious do you sail with Lowes bucket on the transom or is that stowed when underway?

Ed

Sorry just read the entire post, see you were rinsing.

Ed Dewsnap
Marion, MA
1984 Catalina

TippingPoint
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Posts: 46

Because It is hanging from Davits mounted on the tender we use a 5 HP Lehr propane with a 4 man AB rigid (aluminum bottom) the Motor I believe weighs 70 lbs and if I am alone and the wind is right I can get her on a plane.

Ed Dewsnap
Marion, MA
1984 Catalina

two-rocks
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Posts: 74

I have a 9.5' Highield and a 20hp yamaha - it flies.
I't's carried it on a weaver davit system and a weaver motor tilt mechanism so it stays as one. Typically for powerboats, whcih is what we had prior to the C36. Works very well.

These items are above the recommended HP for the dinghy (only a recommendation) and the engine weaver-leaver mechanism. YMMV.

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Chachere
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FWIW, with our Achilles dingy with the high pressure inflatable floor (i.e., not the best for planing), over the years we've used 3 different outboards (thus far):

1) Mercury 5 HP 2 stroke.   Would get it on a plane if no more than 2 passengers.  With a lifting bridle, we were able to stow it on the stern rail; our hoist was a simple snatch block hooked onto the frame of the bimini, which gave no mechanical advantage but allowed for some reasonable amount of control when lowering to the dingy or hoisting back aboard.   Significantly less weight, I'm told, than a 5HP 4 stroke (but significantly worse for the environment).  We still have this outboard, but its been sitting in the basement the past 4 years because I got tired of stripping down and cleaning the carb multiple times each season due to gumming up from ethanol.  

2) Torqeedo 1003 electric outboard.  Equivalent to 3HP.  Will get on plane with no more than 1 passenger.   Since battery easily comes off the motor for storage, I can unload or load this motor onto the dingy with one hand; its that light.  We store on the aft rail or in the aft lazarette.  This is our main outboard now, recharged generally from our boat's solar panels when we're cruising, no need to carry gasoline on our boat, no starting problems.  More than adequate for tooling around harbors; not great for "scooting around" too much (since running it wide open uses up the charge pretty quick).  Ours died near the 4 year mark this summer (we had an extended warranty from Westmarine, so they replaced it).  

3) Yamaha 2HP stroke.  Picked up as a temporary solution while cruising this summer when the Torqeedo crapped out.  Very easy to handle and store on the stern rail (no need for a hoist) and will get you where you are going, but if there's any chop building up in the harbor its a very slow ride.  Tip: prior owner advised using the ethonol-free pre-mix 2 stroke gasoline they sell in hardware stores in order to avoid carb issues; that does seem to work but it rather pricey.
 

Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY

dpower
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Posts: 231

I believe it depends on your needs and intended usage.  If you are going to use it to go from boat in an anchorage to a dinghy dock, you can get by with a small motor that you can easily lift. However,if you need or want to go greater distances within a short time frame, you need something that will get your dinghy up on plane.  We have a Yamaha 9.9 two strike that weighs, I think, around 80 pounds.  With it, our dinghy easily gets up on plane and goes fast enough that it scares me.  We do have a Garhauer engine lift and a bracket on our stern rail.  This is a must, particularly if trying to remove or mount the outboard in choppy waters. My wife often states it is the best improvement we made to our boat.

David S. Power
Two If By Sea #1687
Burnt Store Marina
Punta Gorda, FL

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Chachere
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Of course, "if you need or want to go greater distances within a short time frame" one might eschew having  sailboat in the first place...   Given that when under power we have only our stock Universal M25 (which is rated at a whopping 21 HP) to push around the 19,000 pounds of our C36, it somewhat jades our view, perhaps, of how much HP our 50 pound dingy needs.  
On the other hand, we've had a few guests who wanted to get ashore pretty quickly after enduring a long slow sail (or worse, a long slow motoring)!

Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY

Lanealoha
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Thank you.  

David Lane
S/V Grace
88' Catalina 36'
Oxnard, Ca
 

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pkeyser
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A great fuel for small 4 stroke engines is Mogas. It contains no ethanol or lead so doesn't gum up carborators. It's primarily used for aviation but is legal to run in vehicles too. It's available at small airports. It does cost a premium vs. gas station ethanol blended grades, but is much cheaper than buying the ethanol free gas at garden centers or Home Depot/Lowes.  I've used it for four years and never had to rebuild a carb. I use it in both our outboard and snow blower. The equipment starts with the 1st pull, even after sitting idle for a season.

Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B

McFly
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Dave, this is a great topic.  I think the answer lies within the question of what kind of dinghying you do?? How big is your dinghy, how many people are in it? Are you dragging it? Use davits?  Motor lift vs muscle, etc. 

My philosophy is to have the smallest dinghy that I can get away with.  Our boat lives on a mooring, so we use the dinghy every time we sail, but its usually just me dinghying out, then I swing back by the fuel dock to onload the family and all our crap.  So I can get away with an 8' roll-up dinghy and a small Honda 2.3Hp four stroke.  The motor only weighs 29 lbs so its still light enough that I can manage it (so long as I don't blow out a shoulder!).  I also added a motor strap/handle, which is VERY handy.  There are only a few times per season where I am left wishing I had a bigger tender, but those are fleeting and we seem to make do. 

At the begginning of last season I added an Edson motor mount to the port side stern rail.  I found it used at a local marine salvage, saved a few bucks that way.  The rail spacing wasnt perfect so I had to drill a couple new holes to accomodate the catalina spacing. Other than that it has been great and I firmly believe has saved the wooden transom on our dinghy (West Marine/Zodiac RU260).  I have enclosed a picture of the motor on the mount.  

Good luck, 

Mike

Jackfish Girl, 1999, C36 MKII, Tall Rig, Wing Keel, In-mast furling, Monument Beach, Bourne, MA

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Sojourn
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I have 5 h.p. 4 cycle Nisson powering an 8' Mecury sport inflatable.  Perfect for a couple and 1 guest.  Might move up to 10' boat to carry 2 guests.  That halves thet rips a shore.  I wouldn't change the motor size.  

Note:  I Store the engine on the transom bracket and the dinghy on the bow.  I have a rig to lift the dinghy in and out of the water via the windlass.

Lou Bruska
 

Lou Bruska
Sojourn
1985 C-36 Mk-I TR #495
Eldean Shipyard
Lake Macatawa (Holland, MI) Lake Michigan
Rallyback@comcast.net

pierview
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Re the issue of the carb getting mucked up and the special fuel to avoid this, whenever I am not going to use the outboard for more than a few days I unhook the gas line and run the gas out of the engine/carb... never have a problem. This is on a 4-stroke... I understand that is not a good procedure for a 2-stroke because a 2 - stroke requires the oil in the gas for lubrication.

Chuck Parker
HelenRita 2072 Mk II
2002 Tall Rig - Winged Keel
Atlantic Highlands, NJ

Lanealoha
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Posts: 76

So I've purchased a 9' Inmar 270 TS with the aluminum floor board inserts.  I plan on mostly keeping it de-flated and stowed on deck till needed, if just doing short bumps to new anchorages I'll probably just keep it inflated and on deck.  As for the 'type' of 'dinghying' I plan on doing, mostly just standard getting to and from shore, around anchorages, however we are a family of surfers who will also be using it to get to and from surf spots that we cant readily paddle to from our anchorages, so having a little 'umph' to negotiate currents and swells is desirable.  We are pretty small fully grown adults (haha) with a fly weight almost 12 y/o.  Combined family weight is under 400lbs, probably more like 350 currently, I'm liking the idea of an 8hp for power; but weight, $$ and reality is telling me that a 6hp may be plenty.  Thanks for the input, I appreciate it.

David Lane
S/V Grace
88' Catalina 36'
Oxnard, Ca
 

pierview
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Posts: 582

Dave...

 I use a Tahatsu (sp?)  6 HP and have a Garhauer pully system on my radar mast on the stern. I can tell you if you don't have a system like that to raise and lower the motor the weight makes it very difficult to transfer the motor from the boat to the dinghy and back..... just fyi.

Chuck Parker
HelenRita 2072 Mk II
2002 Tall Rig - Winged Keel
Atlantic Highlands, NJ

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LeslieTroyer
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Sorry I'm late to the party.  I've had 9.9 and 2np 2 strokes in the past.  2hp was way too loud!  When the 9.9 gave up I went with electric start Yamaha 15 hp.  I usually leave on dink and pull up with Davits, but have put on stern with motor lift.  Electric start was for the wife.  9.9 wouldn't plane with me & wife in boat 15 will.  

Les & Trish Troyer
Mahalo 
Everett, WA
1983 C-36 Hull #0094
C-36 MK 1 Technical Editor. 

Commodore

 

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pkeyser
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Les-
What brand davits do you use? A 15HP must be 120 pounds of weight added to the dink.  We have  Garhauer heavy duty davits that support about 160 lbs of weight from the dink and mounted 3.5hp. Our 9.9hp would add another ~40+ pounds. Not sure how comfortable that would be, but would love to move faster.   

Paul & Wendy Keyser
"First Light"
Rye NH
2005 C36 MKII #2257
Wing, M35B

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LeslieTroyer
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Paul they are Martek 600 series - good for 300lbs each. 
111 lbs for outboard  180lbs for dink so even if all weight is on one it's "ok"   

 

Les & Trish Troyer
Mahalo 
Everett, WA
1983 C-36 Hull #0094
C-36 MK 1 Technical Editor. 

Commodore

 

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