Boat Builder Central - Builder Forums

The long leg is the way to go for sure, and yes, this would require a transom mod.

Horsepower dreams? Do they even have 150 tillers?

Longer shaft typically requires higher transom if you don't want the prop lower. This adds more questions for Jacques in there...
1. if I raise the transom, do I need to add more glass/core?
2. do I still need the full height forward bulkhead in the motor well?
3. do I need to increase the hight of the knees (motor well sides)?

I'll run that transom height/modification by Jacques and see what he comes back with. I've only researched as big as 115hp tiller, but I know the motors are getting bigger. I'm leaning to a Yamaha, 70 or 90, but I see Mercury even makes a motor called a Big Tiller now - so they seem to be catering to a growing market.

big motors are needed for heavy boats. I would build the hull and get your base weight. You'll find you are MUCH lighter, even built heavy, than commercial all glass hulls.

The drive for bigger motors is really all about consumer ... silliness. Too much structure (center console, living room style seating) is the biggest one. Add the "no wood no rot" stupid driving to solid glass (no core). Then you have my favorite, the "more power" boys (thank you Tim). If you build the boat you are talking about, I think you'll be overpowered with a 90. The boat will handle it, you just won't need it.

I'm a grumpy old man who thinks 9.9 is oversized for my 24' sailboat. So take all that with a couple grains of salt.

As noted above, the Yamaha 70hp is only available in 20" shaft. Will have to go to 90hp to get a 25"shaft. That may limit my options if i truly do need to raise the transom to guarantee tiller clearance.

Toms wrote: ↑Wed Sep 21, 2022 11:05 am
One comment from TomW1 - about motor shaft length got my attention. if a 25" shaft would allow tiller clearance without modifying the rear bulkhead, am I correct to assume that it will require me to raise/modify the transom?

Thanks again - great stuff and quite helpful in wrapping my head around things!

Yes, that will need to be the case. But not the whole transom just the cut out for the motor will need to be raised by 5". But also check the plans that line may also be in them. No other changes are needed due to the strength of the transom.

Tom

TomW1 - your comment - Yes, that will need to be the case. But not the whole transom just the cut out for the motor will need to be raised by 5". But also check the plans that line may also be in them. No other changes are needed due to the strength of the transom.
Perfect, and I assumed that may be the case. I did look at the plans quickly and doing away with the "standard" transom cut-out, (cut it straight across or similar) seems it could easily solve the tiller clearance concern. Next problem is to see if this can be accommodated in production of a CNC kit! I'm planning on going the CNC kit route. It seems simple to me - but not sure if that little change would be a big deal when producing a CNC kit where I'm sure the design is already setup. I just don't know anything about that process...

5.5" there fellas...fyi is all

leg is 5" higher vertical, panel at 12 degrees is 5.5" more panel

TomW1 wrote: ↑Tue Sep 20, 2022 7:24 pm Two things you need to do is buy the long shaft motor which will raise the motor from 20 to 25" and then purchase a tiller extension so that you are sitting more forward in the C19….
Tom

25” is XL extra long; 20” is L long shaft.

I think this arrangement would be ultra utilitarian. Like a bigger version of the skiff here:
viewtopic.php?p=495727#p495727

There was an amazing 27 Rambo built with a tiller 150 and a mini console on the back of a central coffin box. I only have one grainy pic though. IMO what the CG thinks for power is irrelevant unless you want to carry passengers for hire. For bigger power a steering damper might be a good idea on longer runs.

I’d consider trim tabs to control pitch underway and help running through chop.

Please build it so we can watch and cheer you on!

Matt Gent wrote: ↑Thu Sep 22, 2022 11:08 pm

TomW1 wrote: ↑Tue Sep 20, 2022 7:24 pm Two things you need to do is buy the long shaft motor which will raise the motor from 20 to 25" and then purchase a tiller extension so that you are sitting more forward in the C19….
Tom

25” is XL extra long; 20” is L long shaft.

I think this arrangement would be ultra utilitarian. Like a bigger version of the skiff here:
viewtopic.php?p=495727#p495727

There was an amazing 27 Rambo built with a tiller 150 and a mini console on the back of a central coffin box. I only have one grainy pic though. IMO what the CG thinks for power is irrelevant unless you want to carry passengers for hire. For bigger power a steering damper might be a good idea on longer runs.

I’d consider trim tabs to control pitch underway and help running through chop.

Please build it so we can watch and cheer you on!

Thanks Matt,
All good thoughts and actually things I've already considered. I've heard torque can be pretty tough on these big tillers, so looking at options to tame that if I find I need it. Same with trim tabs... I'm hoping to build this boat and get it on the water and find out first hand if trim tabs are needed - but they are already in my head. Hope I can add these items after the fact if they are truly needed. Again - I'm set on a simple boat in design and function, with as few gadgets as truly required. The less there is to break, mess with and maintain, the more I like it! My current Mako sits in my driveway more than it's in the water, and still seems to cost me $ every other time I run it.
Thanks!