Just mounted new 15hp yamaha 4stk on my 79 H27. I reinforced transom with angle iron bracing running forward and tied in to several areas forming a "box" structure the whole thing is rock solid and 0 flex at transom. The motor is remarkably quite and smooth easily pushing my boat against strong wind,current,and chop to hull speed at about 2/3 throttle in NY harbour. And no engine racket . HOW COME a small,quite,compact motor such as this one as not been adapted for inboard use? I realize traditional inboards gas/diesel have to power an alternater which robs a lot off power under load but the charging system from outboard should be plenty for medium sized boats. cheers frank
outboard puzzle?
- Thread starter fnuttersny
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Frank, Got to think it is nothing more then marketing. Years ago OMC had a outboard engine that was converted to an "inboard" using a sail drive. Was not very well accepted by the "spending" public. Partly because of the 2 stroke vs 4 stroke I suspect. With the exception of Honda engines the small marine four stroke is relatively new. Also got to believe the general public has a unwarranted fear of gas vs diesel. These small engine you refer to are all vertical shafts vs most inboard applications are horizontal shafts. Not a bad idea on your part just don't think it would sell to well.
Marketing and public acceptance are the issues. Two or 3 cyl gas engines can be strong and quiet and can be made very safe but I doubt the public would go for it. Don't underestimate the durability, fuel stability and infrastructure available for diesels.
Hey Frank,
That's a lot of power for a 27!!!! LOL
Is the stern squatting when you got the motor cranking? Are you getting any water coming up through the scuppers?
If you got any pictures of the transom reenforcement would you mind posting them? I bought a new mount to accomodate the extra weight of our new Honda and I want to beef up the transom. I'm looking for ideas.
Thanks,
Manny
That's a lot of power for a 27!!!! LOL
Is the stern squatting when you got the motor cranking? Are you getting any water coming up through the scuppers?
If you got any pictures of the transom reenforcement would you mind posting them? I bought a new mount to accomodate the extra weight of our new Honda and I want to beef up the transom. I'm looking for ideas.
Thanks,
Manny
Hi Manny, Boat does not squat and no water in scuppers. Motor weighs no more than your Honda. I think the 15hp is a jacked up 9.9hp almost no weight diff. I got a great deal on "garelick 71090" bracket and 09 hardley used motor from friend who lost boat . I coudn't pass it up for 1500 bucks. I placed bracket same place as yours but lower. The bottom right sticks about about 3 inches below transom radius. The bracket is rock solid with no play and easily lifts motor up with spring. The 15" throw unit would have been better for height placement but would also have placed moment/weight to far out plus it came with motor. Bracket came with 3x2x12 inch hard ruber spacers and I made 3/4'" plywood backing plate with 4 5/16ss bolts. I made a bracket from 1/8 angle iron that sits on protruding 5/16 studs from motor bracket inside and one braket with flange "looking" at stern on fiberglass stiffener located about 2' from stern. I then bolted 2 angle iron braces to the flanges distributing the load to stiffener. I also placed angle iron bracket from lower motor bracket bolt inside to cockpitside at 45deg. angle. I used my boat a lot in my first season and often "making passage" was impractical under sail and 8hp in my waters (Hudson river NYC area) left me motionless to often against ragging tide and wind. I well post pics soon....cheers frank
For me reliability would be the main issue comparing a diesel to any gas engine. It may be unfounded, maybe a gas Honda in the larger size is a reliable engine. I have two smaller ones, both 4-cycle, and they are crap. And I know all about clean gasoline, running them dry, etc. Gas on the boat is more than a minor thing also.
Ed,I know that some of the small 4stk outboards aren't that great, many are aircooled with automatic transmitions and I agree crappy. My new 15hp Yamaha, however, is beautifully built , highly rated and sofisticated in desighn. It starts first pull is dead quite and smooth like sewing machine. As for gas I'm not a big fan either or propane for that mater but it is as safe as you make it. Also Manny's set up and mine are a compromise at best and is a temp. solution. I think we and others sometimes have difficulty justifing a diesel upgrade on a 27 footer because we can get away with outbard. On our boats ratio of boat value vs engine is about 50/50. On larger boats it drops way off and you have no practical option either. I know we are both keeping an eye open for a realy good deal on replacement. In my case I think I would move up to a fully upgraded 37 or so first. ...cheers frank
Believe me, I do understand the financials associated with your choice. Having made the trip from Lake Erie to west Florida though I cannot imagine anything but a reliable diesel. I would not have appreciated that had I stayed on Lake Erie where all I needed was ten minutes to clear the lighthouse. I used to think electric was the answer. Just depends on how you use the boat. I have a motor for my Highlander but generally sail off the dock and paddle back. Now that's quiet!!
Considering the boat was originally powered by a low rev, 6.5 hp diesel auxiliary does not surprise me it takes a 15hp gas powered outboard to do a similar job.
Actually Benny the 15hp yamaha does a bit more than similar job. It lets me plan my trip regardles of tide and wind. NYC (120 miles roundtrip) will be an easy weekend get away. For us it is a nice option...cheers frank
Hey Frank - thanks for the description. I think I follow what you described but I'm not sure about the fiberglass stiffener... Do you mean the shelf under the lazarette or the reinforced center section of the transom where the ladder is? Oh by the way - good deal on the motor and the bracket! I picked up the same garelick but in the longer throw, i think it is the 71091. The weather hasn't been to good for me for installing the new mount yet, I want to make sure I properly reinforce the transom first. I finally got the old one off and epoxied the holes up, used a mockup out of cardboard to get an idea of what I can & can't do. I'm actually considering removing the swim ladder and mounting the outboard there...
Ed - I would love nothing more than to put in a nice smooth 2 cylinder diesel in the boat. Franks right about the cost ratio, even used it would probably cost more than the boat did... I'm on my second Honda... The first one (8 Hp) we bought used and was 11 years old by the time I overcooked it by letting idle while in some weeds. Up to that point it ran like a brand new motor. Started on first pull just about every time. I had a lower pitch prop on it and it was plenty of power for the 27. Even after the "event" it would still run perfectly but I found evidence of water in the oil... The admiral wanted a motor with electric start so we bought a new 9.9 hp. It doesn't really push the boat any faster but it's quieter and has a 12 amp alternator which is plenty for us. My wife and I took an almost two week cruise on the Chesapeake this past fall and it handled everything we encountered with ease. Had the roughest weather I ever experienced on a boat and pushed us through no problem. Also got us out of the mud a couple of times LOL.
Manny
Ed - I would love nothing more than to put in a nice smooth 2 cylinder diesel in the boat. Franks right about the cost ratio, even used it would probably cost more than the boat did... I'm on my second Honda... The first one (8 Hp) we bought used and was 11 years old by the time I overcooked it by letting idle while in some weeds. Up to that point it ran like a brand new motor. Started on first pull just about every time. I had a lower pitch prop on it and it was plenty of power for the 27. Even after the "event" it would still run perfectly but I found evidence of water in the oil... The admiral wanted a motor with electric start so we bought a new 9.9 hp. It doesn't really push the boat any faster but it's quieter and has a 12 amp alternator which is plenty for us. My wife and I took an almost two week cruise on the Chesapeake this past fall and it handled everything we encountered with ease. Had the roughest weather I ever experienced on a boat and pushed us through no problem. Also got us out of the mud a couple of times LOL.
Manny
Manny, below stern side edge of stbd. cockpiit locker lid I have a glassed in diveder/stiffener jutting out from outer hull and bottom torwards cockpit..like mini bulkhead parralel with stern...and about 2ft from stern towrds bow. I ran bracing between there and stern structuraly boxiing in the area from stern forward directly behind motormount. I also braced back of mount not to lader area but stbd side of cockpit in laz. My boat has a well behind rudder post structure and is very solid back there with plenty of places to bolt stuff on. BTW I you are right motor may be over killl but I can reach hull speed at less than 1/2 throttle. Kind of nice to have more power than needed than the other way around...I thought about moving setup to center but like keeping stern open plus easier to service motor dockside..cheers frank
I'm still kind of lost about the divider... It sounds like my setup is different. My starboard lazarette has a fiberglass shelf that my diesel tank sits on and then a ply "bulkhead" from the shelf to the cockpit floor. It does not run the full length of the shelf and if memory serves it's just screwed in.
Manny
Thats the one Manny and yours is different. It holds up shelf and mine is also wood but glassed in all around and stops short about a foot from lazz. ld. but runs down deep into hull bottom. The top of that piece is about even with top bolts of engine mount in my case. So I just basicaly bolted the top of that piece to the back of engine mount bolts at backingplate using 1/8 angle iron pieces to suite....thats all.... it immediatley took flex out of stern. In fact I stood on extended mount with motor and bounced up and down and saw no movement. You should be able to something similar. I actually got idea from your post in archieve discussing fiberglass fatigue and someone recomended bracing/tying in stern to rest of hull to distribute push from behind load which is real isssue not up and down or shear load on whole set up.
Manny I forgot to mention that I also ran a a couple of 2' pieces forward of "little bulkead" at angle to tie in to cockpit side about 4" from cockpit floor so transom is now totaly intigral . Also, did you ever change prop on honda for more torque at given RPM? It was suggusted for sailboat where speed is not issue....frank
Hi Frank - On my old 8 hp outboard I found that Michigan Wheel had a lower pitch prop which I put on. It did make a noticeable difference. I haven't looked much for the new outboard but I am thinking of doing the same thing if a prop is available. Its already the power thrust model so the pitch is lower, but the engine can't get to full revs with the prop now so i'm not getting full advantage of the higher hp in the engine.
I really would like to see pictures of your transom reinforcement, I'm trying to envision the angle pieces you just mentioned.
Manny
I really would like to see pictures of your transom reinforcement, I'm trying to envision the angle pieces you just mentioned.
Manny
Manny, I may be down there this weekend so I'll take photos then. I just tied in bracing from top of stiffener going forward then bending it towrds center of boat untill it lands against cockpit side about halfway between lazz lid and floor top to bottom. My boat is tiller so my throttle quadrent is forward of where I tied in bracing. So to clarify..If you where facing forward looking down at plan of boat I just baically ran parallel struts from top motormount bolts forward to stiffener (little bulkhead) and continued on other side of it with more bracing bent left to cockpit side. It doesn't mater much where you tie in because all your doing is tieing in transom in way of motor mount to rest of boat and so on any where you can depending on your set up. Anyway I'll get pics as soon as I can...cheers frank
Thanks Frank - I didn't realize yours was a tiller model so I'm sure there are few differences, but I think I am starting to understand what you did. I picked up some angle iron yesterday and I plan to try installing the mount using some of your ideas this weekend. I'll try and take some pictures also. Since you have a tiller, is your cockpit still T shaped? Not to change the subject but how is the tiller feel, is it pretty heavy when sailing? With the amount of weather helm the 27' has you might get a good workout!
Manny
Manny
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