convert a tohatsu 90hp from 25"shaft to 20"

[mattsaks]

is this possible on a 1996 90hp tohatsu? what would be required in parts etc? it appears to have a 5" spacer plate. can i remove and get a shorter driveshaft?

 

[TOHATSU GURU]

Re: convert a tohatsu 90hp from 25"shaft to 20"

Easy enough to do. You would need a driveshaft, watertube, shiftrod and engine base gasket.

 

[mattsaks]

Re: convert a tohatsu 90hp from 25"shaft to 20"

so does this mean you have to take the powerhead off?

 

[TOHATSU GURU]

Re: convert a tohatsu 90hp from 25"shaft to 20"

Yep, the watertube has to be replaced from the top.....Of course you could just cut off 5 inches(that was really hard to write) off the tube that is already there. That would save the cost of a new tube and basegasket as well as the labor to pull the head.

 

[mattsaks]

Re: convert a tohatsu 90hp from 25"shaft to 20"

a guy here reckons that you could just cut the driveshaft and re-spline it. any thoughts on that?

 

[TOHATSU GURU]

Re: convert a tohatsu 90hp from 25"shaft to 20"

I do not think that it would be cost effective, but there's no harm in getting a quote from a machine shop.

 

[mattsaks]

Re: convert a tohatsu 90hp from 25"shaft to 20"

sounds like it might be a go. does the d/shaft come out with the lower unit or do you have to pull it down out of the power head?

 

[TOHATSU GURU]

Re: convert a tohatsu 90hp from 25"shaft to 20"

Comes out with the LU

 

[mattsaks]

Re: convert a tohatsu 90hp from 25"shaft to 20"

The other thing i have heard is that there is an extension on the shift rod that can be removed. This is getting easier with every post!!

 

[TOHATSU GURU]

Re: convert a tohatsu 90hp from 25"shaft to 20"

No, the shift rod is a single piece.

 

[mattsaks]

Re: convert a tohatsu 90hp from 25"shaft to 20"

Ok. Thanks for all your help Elvin!! Will let you know how it goes...

 

[mattsaks]

Re: convert a tohatsu 90hp from 25"shaft to 20"

Also, what is involved to pull the driveshaft out of the lower unit?

 

[TOHATSU GURU]

Re: convert a tohatsu 90hp from 25"shaft to 20"

You have to pull the bearing carrier and then remove the nut from the bottom of the drive shaft. Its a little harder than it sounds.

 

[mattsaks]

Re: convert a tohatsu 90hp from 25"shaft to 20"

Ok. So I now have the lower unit off. Two questions: I have removed the bolts on either side of the prop spline (and the prop)but the housing will not budge. I'm not sure how much force to use on it as i dont want to break it! Any tips?<br />Also, how crucial is the angled cut on the water tube? Will i need to cut the tube the same when i shorten it? or will a straight cut do?

 

[TOHATSU GURU]

Re: convert a tohatsu 90hp from 25"shaft to 20"

On the carrier: tap it sideways to turn it so you can tap it from the reverse side. A little force goes a long way so don't brutalize it. The angled cut is important as it determines how the water is put into the pump.

 

[mattsaks]

Re: convert a tohatsu 90hp from 25"shaft to 20"

No, shes not going anywhere!! looks like i'm stuck with a longshaft... Hopefully i can at least change the propshaft seal in place?

 

[TOHATSU GURU]

Re: convert a tohatsu 90hp from 25"shaft to 20"

Anything is possible, but you really need to get that carrier out.

 

[Salmon Tub]

Re: convert a tohatsu 90hp from 25"shaft to 20"

Matt, if the lower unit is drained of oil, remove the drain plug so that you are not pulling against a vaccuum. Also, there is an O-ring there, you may want to have a fresh one handy just in case. Good luck.