Suzuki DT15c Short or Long Shaft?

Skook

Seaman Apprentice
Joined
Apr 8, 2009
Messages
47
Recently, I purchased my first boat (used 1995 Alumacraft V-14), and it came equipped with a Suzuki DT15c outboard. The previous owner used the boat in a shallow river, and so he raised the 15" transom to 20" to get the motor up out of the rocks a bit.

A friend of mine who is familiar with boats and motors looked at it and told me that the transom was too high for that motor, and so we spent the better part of a day undoing what the previous owner had done and lowered the transom back to its original 15" height.

After doing that, I was thinking that the motor was too long. I looked around on the Internet and found a few sites that showed me how to measure the shaft length. According to my measurements, the shaft length is something like 17" or so. I was under the impression that short shafts are close to 15" and long shafts are about 20".

So do I have a short shaft or a long shaft, or neither? With the D-I-Y 20" transom, the motor would not have been low enough in the water; however, with the 15" transom in place, it looks a bit too long.

I guess too long is better than too short, but it just makes me wonder what shaft length this is. I'm thinking about a mini-jacker, but I don't know if it's necessary. Any thoughts?

Also, any other thoughts on the DT15c that I should know about?

Thanks.
 

Whoopbass

Chief Petty Officer
Joined
Jun 29, 2006
Messages
649
Re: Suzuki DT15c Short or Long Shaft?

Sounds like you have a longshaft since it would be impossible to raise the transom 5" and still get a shortshaft to work.

The cavitation plate on the outboard should be even with the bottom of the boat.
 

Skook

Seaman Apprentice
Joined
Apr 8, 2009
Messages
47
Re: Suzuki DT15c Short or Long Shaft?

That's the weird part. I measured the raised transom before I lowered it back, and it was 20". However, the cavitation plate was above the bottom of the boat by an inch or two or three (don't remember exactly). Even to a noob like me, it just looked too short. That's why my friend said it needed to be lowered back for that motor. The previous owner admitted that the motor's performance was somewhat degraded after his fix, but he said it worked fine for him in the river.

However, with the transom back to 15", the motor seems a bit long. It's almost like it's an intermediate shaft, even though one does not exist that I know of.

I'll try to add a pic, but I'm not too good at this computer stuff.

odossey002.jpg
 

James R

Commander
Joined
Feb 1, 2007
Messages
2,664
Re: Suzuki DT15c Short or Long Shaft?

Measure from the point that the motor hooks on to the transom to the centerline of the prop shaft. If you have a short shaft, that is a 15 inch, the measurement will be about 24 inches. The measurement from the top of the transom to the bottom of the hull determines the length of the shaft, ie 15, 20 or 25 inches. I any event the level of the anti cavitation plate should be close to the bottom of the hull.
 

Whoopbass

Chief Petty Officer
Joined
Jun 29, 2006
Messages
649
Re: Suzuki DT15c Short or Long Shaft?

How it is set up in the pic looks right to me. Your outboard looks like a short shaft.
Does the boat perform well how it is?
 

Mas

Lieutenant Commander
Joined
Oct 3, 2006
Messages
1,656
Re: Suzuki DT15c Short or Long Shaft?

It's hard to tell from the angle of the picture, but the horizontal cav plate directly above the prop should be even or slightly below the bottom of the hull. If the motor is above it, you'll suck a lot of air and your motor will over rev.

MAS
 

Skook

Seaman Apprentice
Joined
Apr 8, 2009
Messages
47
Re: Suzuki DT15c Short or Long Shaft?

Thanks, everyone. That picture was taken by the previous owner before I bought the boat, and it shows the D-I-Y transom at 20". It's tough to tell in that picture, but the cavitation plate was above the bottom of the hull before I lowered the transom back to 15".

I no longer have the motor attached to the boat, and so I can't easily take a better picture. IIRC, at 15", the cavitation plate is below the hull. I guess below the hull is better than above the hull.

If you look closely, you can see the line on the transom where the extra 5" was added. I now have it back to the original 15", where the line is. Imagine the motor mounted where that line is, and you can imagine that it would look a bit long.
 

ebsworj

Petty Officer 2nd Class
Joined
Mar 7, 2005
Messages
173
Re: Suzuki DT15c Short or Long Shaft?

Hi I just bought a DT15C. I haven't run it yet since I don't have the fuel connector and the "emergency kill switch lanyard" is gone too.

Mine has this wire comming out the the front of the motor and it's be cut off. I don't know what it is. Is it for a charging system? Could that be what teh "C" stands for? I know it dosen't have electric start.
 

ebsworj

Petty Officer 2nd Class
Joined
Mar 7, 2005
Messages
173
Re: Suzuki DT15c Short or Long Shaft?

Hi I just bought a DT15C. I haven't run it yet since I don't have the fuel connector and the "emergency kill switch lanyard" is gone too.

Mine has this wire comming out the the front of the motor and it's be cut off. I don't know what it is. Is it for a charging system? Could that be what teh "C" stands for? I know it dosen't have electric start.
 
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