short shaft to long shaft

[gaelforce]

Hi,

I'm looking at a couple of options for engine replacement and wondering how much of a job it is to convert a short shaft engine to a long shaft or even vice versa.
Is it just a case of adding some sort of mid-section and getting a longer shaft, or is it possible at all?

[Nos4r2]

On what motor?

Generally, it's prohibitively expensive to change shaft lengths on a motor.


There's a couple of exceptions, but they're from the early 70s.

[gaelforce]

Thanks for the reply. One of the options is a sizuki 70 longshaft that we hoped could be changed to a short shaft by maybe taking out a section and changing shafts to a short one. Just wondering would the bottom unit line up with the shorter mid section and are the shafts compatible at the ends?

[Nos4r2]

I don't think you'll find a short driveshaft for a Suzuki 70, and cutting lumps off the mid section isn't practical or safe really.

The only motors it's really feasable on are the old late 70's/80's 40hp Mariners that the RNLI used to use, and Johnson/Evinrudes from the 70's.

[Turbodiesel]

Its pretty easy to go from short to long or Xl there are kits for most common brands that will cost about £300-£400 for a kit.

[thomas]

I did a Yamaha a few years ago, quote an easy job and a good exercise to learn about gearboxes.

[EnglishLes]

I have aEvinrude 15hp in both short and long shaft versions. They are both from the mid 80s. They were both on e-bay as non-runners, I bought the 2nd to use as parts. They both run now but one is better than the other. The better one is long shaft,this seems to have an extension in the leg just above the gear box. My boat uses a short shaft.

Is it possible to swap the bottom bits around taking the drive shaft, gear change rod, exhaust and water pipes where they are different lengths?

Is there anything that locks these bits into the top of the leg/bottom of the engine?

I already know how to undo the gear change rod.

I will put new impellors in and change the gear box oil when I do this. Is there anything else I should do whilst they are in pieces.

Thanks Guys

[Downhilldai]

Originally Posted by gaelforce

Thanks for the reply. One of the options is a sizuki 70 longshaft that we hoped could be changed to a short shaft by maybe taking out a section and changing shafts to a short one. Just wondering would the bottom unit line up with the shorter mid section and are the shafts compatible at the ends?

What boat do you have that needs a 70hp shorty?

[Nos4r2]

Originally Posted by Turbodiesel

Its pretty easy to go from short to long or Xl there are kits for most common brands that will cost about £300-£400 for a kit.

Not the other way round though- he asked about making a long into a short.

Originally Posted by EnglishLes

I have aEvinrude 15hp in both short and long shaft versions. They are both from the mid 80s. They were both on e-bay as non-runners, I bought the 2nd to use as parts. They both run now but one is better than the other. The better one is long shaft,this seems to have an extension in the leg just above the gear box. My boat uses a short shaft.

Is it possible to swap the bottom bits around taking the drive shaft, gear change rod, exhaust and water pipes where they are different lengths?

Is there anything that locks these bits into the top of the leg/bottom of the engine?

I already know how to undo the gear change rod.

I will put new impellors in and change the gear box oil when I do this. Is there anything else I should do whilst they are in pieces.

Thanks Guys

Why not just swap the powerheads over?

[9D280]

As Nos says, 1960s/ 70s Johnsorudes used shaft extension pieces, so it;s "simply" a case of finding a spacer, and long drive shaft / Exhaust & water tubes.

More modern stuff tesnde to be the same innards, but has separate long & short shaft castings for the leg.

Depending which way you want to go on what engione there is a tiny chance I may be able to help, having threatened to scrap this lot but never managed to get round to the tip - sorry recycling centre with it in the car boot whn the place was open!

I have a Yam 50-90 Longhshaft leg off a mid 90s 2- stroke (may also have the exhaust tube, but can't remember), a Suz DT25/50 Longhshaft leg (Both for the cost of the postage) and if you want to stretch an Early 70s Johnsorude 20 I will swap a set of long shaft gear (LS drive / water &exhaust + spacer) for the short shaft drive / exhaust & water tube.

Pics available in the depths of the bits & pieces thread.....

[Downhilldai]

Hey 9D280: I'll take the DT25 midsection off you, if you can get a price on postage?

[9D280]

OK, will do.

Alternatively any ribnetters doing a Scotland - Wales trip?

Edit -
just noticed my fat finger moment. That sould read DT25/30 , not 50.

Let me know if that changes things!