Long shaft vs short shaft

[Uncle Krusty]

I'm looking at buying a 12' Duroboat. I think the transom is 15", which puts in in short shaft territory, which is a hard used motor to find in my neighborhood. How bad would it be to run a long shaft? Would it be dangerous or just not perform as well? The boat seems to be rated for up to 20hp, but I'd probably be looking for a 15.

 

[MRS]

it would be to deep in the water and not work well at all. Why not get the right motor for the transom?

 

[ahicks]

I'm looking at buying a 12' Duroboat. I think the transom is 15", which puts in in short shaft territory, which is a hard used motor to find in my neighborhood. How bad would it be to run a long shaft? Would it be dangerous or just not perform as well? The boat seems to be rated for up to 20hp, but I'd probably be looking for a 15.

It would be different if you were replacing a motor on a boat you had sentimental ties to.

While shopping for a boat, keep looking....

 

[Sea Rider]

The cheepest Duroboat is the 12D model whcich is rated for a 15S shaft motor, the 12L is rated for a 15 L shaft but costs way more than the 15S.

Which 15 HP brand motor, assume a tiller one will you be looking for ? If a short shaft motor isn't available can always install a 5 inch transom metal mount to raise the L motor which should cost way less than going for the 12 L boat.

Happy Boating​

 

[Texasmark]

Since you are talking about 15 hp, you can add a 5" extension to your transom....BTDT. You can build up some quality plywood to the thickness required to match the current transom and cover it with sheet aluminum or if in fresh water, galvanized steel...probably easier to get....AC duct work fab shops a source. Use a single piece making an inverted U shape, as many layers as you want to get the thickness you want, through bolt it to the old and new wood with 3M 5200 sealer on the bolts.

Mount the engine and with a helper, engine down in the run position, pointed straight ahead, take your foot and put down pressure on the AV plate of the engine and check for rigidity. If ok, fine. If not add an additional transom brace between the engine clamps on the extension.

If you do it right you will also reduce your "water over the transom" that has always been a problem with tiller operated, one person boats with 15" transoms as it will have 20" to climb before coming in the boat.

A fabricated "splash well " type bracket attached all the way across the transom would be a super brace and would/could provide extra splash protection too....just leave a place for any captured water to drain back out.

 

[racerone]

Many Johnson / Evinrude models are simple to convert from long to short shaft.----Be less work than raising transom of your boat.

 

[Uncle Krusty]

This is what happens when you're both cheap and don't have a lot of money for the project. I haven't seen the boat yet, so I'm not sure what model it is, but at $500, it's as cheap a good boat and trailer as I'm going to find. Used SS motors are scarce around here. I'd love a new/newer 4 stroke, but can't justify the expense. I'll think about building up the transom, but I'm not very handy. It would probably fall off in the middle of the Columbia!

And, you know, I just looked at the pictures again and this boat doesn't have a cut out transom. It might take a long shaft after all. I gotta go measure it.
And I just sent a message to Larry at Duroboat.

 

[Sea Rider]

Seems a Long Shaft transom to me. Have seen short and long shaft boat's transoms without the middle transom cut. Find out the exact transom size and go from there.

Lower leg conversions from S to L it's usually expensive to go for unless buying scrap parts, second hand ones. Do you have in mind any particular 15 HP motor brand to look after ?

Happy Boating​

 

[Uncle Krusty]

Seems a Long Shaft transom to me. Have seen short and long shaft boat's transoms without the middle transom cut. Find out the exact transom size and go from there.

Lower leg conversions from S to L it's usually expensive to go for unless buying scrap parts, second hand ones. Do you have in mind any particular 15 HP motor brand to look after ?

Happy Boating​

I really want to hold out for a four stroke, reasonably recent year. Aside from Honda I don't have a specific brand in mind. Are there brands to avoid? Seems to me that how the motor has been maintained is more important than brand, but that's hard to determine. If I see it run, check the compression and the lower end oil and whether it looks like it's been abused, I guess that's about all I can do.

 

[JimS123]

Boats that are suited for a 15 HP motor more often than not are short shaft. Not always, but more often than not. In my neighborhood, finding a long shaft 15 would be a chore. I can't understand why a SS would be a problem.

OTOH, you say you're cheap and don't have a lot of money. In that case a 4-stroke probably wouldn't be in your future.

 

[Uncle Krusty]

Boats that are suited for a 15 HP motor more often than not are short shaft. Not always, but more often than not. In my neighborhood, finding a long shaft 15 would be a chore. I can't understand why a SS would be a problem.

OTOH, you say you're cheap and don't have a lot of money. In that case a 4-stroke probably wouldn't be in your future.

The guy at Duroboat said it needs a long shaft. I'd part with 1500-2000 for a good 4 stroke. I think. I wonder how a 9.9 would do on this boat.

 

[Texasmark]

The guy at Duroboat said it needs a long shaft. I'd part with 1500-2000 for a good 4 stroke. I think. I wonder how a 9.9 would do on this boat.

Looks like a 20" to me too. On 9.9, what's your pleasure? You alone with tackle should plane out nicely if you distribute your contents to get some weight forward....tiller operated boats usually have a bow high problem when single occupant.....a fishing buddy solves that problem but git a skinny one if you opt for the 9.9. Grin. When I was a teenager and rented boats, I had a 10 hp because it was a HP-weight compromise...my lifting and all that.

 

[JimS123]

The best 15 HP LS online is $2735 with free shipping. You won't find a local dealer that will beat that.

Its just a little shallow 12 footer. If you look at the pic and try to scale the transom to the bunks (probably twobafores) or the trail lights, it looks SS to me. But that's just an unedumacated guess. OTOH how often do you find a guy that knows whats what? Drop a tape on the transom (do it yourself) and you'll have the right answer.

 

[Uncle Krusty]

Yup, I'll measure it, as well as go over the hull with a fine tooth comb. It looks to me like this might be the biggest 12' boat around, with very high sides. But I do wish it was a 14'...

 

[Texasmark]

Yup, I'll measure it, as well as go over the hull with a fine tooth comb. It looks to me like this might be the biggest 12' boat around, with very high sides. But I do wish it was a 14'...

I used a 10' Lowe brand Lake John for years with a 7 ½ Merc. For a 10' John, it was wider and higher sides. I chose 10' because of the car-top usage and confined spaces where I boated at the time...maneuverable easily with a paddle. The 7 ½ planed it out fast on the hole shot and a good clip up and running with me and tackle. I don't remember the rating. A 9.9 would have made it fly.

The comment here deals with what you said about what you are looking at in terms of it is a lot of boat for 12'. I have seen 14' Johns that I wouldn't get in and would take my 10' in those waters without question.

 

[Lowlysubaruguy]

Rectangular tube aluminum sandwiched between two pieces of 3/16” diamond plate aluminum over both sides of the transom and the full height and width of the outboards mounting area with galvanized bolts and lock nuts holding it all together would be my recommendations. aluminum cuts easily Looks good doesn’t rot. I’d use galvanized bolts not only because there stronger than stainless but cheaper stainless bolts break threads deform etc they have there place But i used stainless on my trolling motor bracket a few times it bolts on or off for different uses the stainless bolts fractured nuts seized up seemed like every time I took it off I had to replace half the bolts ive been using the same galvanized bolts for decades now. Myself I would weld it all and only have bolts in the transom but I have that for an option. Find a metal supermarket near you after you figure out what height you need your costs wont be that much.

 

[Uncle Krusty]

I used a 10' Lowe brand Lake John for years with a 7 ½ Merc. For a 10' John, it was wider and higher sides. I chose 10' because of the car-top usage and confined spaces where I boated at the time...maneuverable easily with a paddle. The 7 ½ planed it out fast on the hole shot and a good clip up and running with me and tackle. I don't remember the rating. A 9.9 would have made it fly.

The comment here deals with what you said about what you are looking at in terms of it is a lot of boat for 12'. I have seen 14' Johns that I wouldn't get in and would take my 10' in those waters without question.

If I buy it I'll post a pic. If I find a motor, I'll post a pic from the lake. That might take a while...

 

[Uncle Krusty]

Rectangular tube aluminum sandwiched between two pieces of 3/16” diamond plate aluminum over both sides of the transom and the full height and width of the outboards mounting area with galvanized bolts and lock nuts holding it all together would be my recommendations. aluminum cuts easily Looks good doesn’t rot. I’d use galvanized bolts not only because there stronger than stainless but cheaper stainless bolts break threads deform etc they have there place But i used stainless on my trolling motor bracket a few times it bolts on or off for different uses the stainless bolts fractured nuts seized up seemed like every time I took it off I had to replace half the bolts ive been using the same galvanized bolts for decades now. Myself I would weld it all and only have bolts in the transom but I have that for an option. Find a metal supermarket near you after you figure out what height you need your costs wont be that much.

Surprising that stainless hardware doesn't hold up. I wasn't aware there were differing grades. Do you boat in the salt? My boat has been crabbing a lot and the galvanized bolts are badly corroded while the stainless look fine.

 

[racerone]

Hopefully they use stainless bolts on those big multi engine center consoles.-----See them on those ---haulover inlet videos.-----You would not want those $35,000 motors to fall off.-----Not all STAINLESS is the same.

 

[Uncle Krusty]

I have seen those, pretty wild.