Using roundnose driveline in squarenose SJ?

[DBLOCK]

So, I bought a nice driveline off of a guy parting out a busted up roundnose. Got the parts (pump, driveshaft, midshaft assy) and they look really nice. I test fitted the midshaft assy to the bulkhead and the hole pattern is larger. I haven't tried the pump assembly yet.

Anyone else put the newer driveline into a squarenose hull before? I'd sure like some advice on how to shoehorn this in to my ski since I already have it in hand...

Thanks,
Dennis

 

[Crab]

Just add ball bearings.

 

[sjetrider]

The only problems you will have is the midshaft carrier if you sn is pre 93. Everything else will be ok.

 

[Crab]

Hey Dennis, bout time you come over to the wild side. You will find the answers here.

 

[WaveDemon]

sjet is right. the only differnce is the 650 squares (90-93)have a diferent bolt pattern for the mid shaft. everything else will bolt up fine.

 

[DBLOCK]

Hey Crabman!

Cool deal on your 650. Whatcha going to do to it? Put it into your standup hull?

I can't wait until this project ski is all put together. I haven't laid the glass yet - worked over the cracks some more tonight, cleaned the area out & washed it all up with acetone. It's drying out right now.

Maybe I'll mix the epoxy tomorrow.

Regarding the midshaft assembly - the hull is from a '91 650... I thought I had to match the midshaft assembly to the pump/driveline assembly splines - thinking this was similar to an old piston port js550 to SX conversion.

I won't be able to use the old midshaft assembly I have laying around - it's from a '95 hull. The '91 hull came to me bare. Guess I'm now looking for a pre '93 midshaft assembly?

 

[Crab]

10-4 good buddy, make it run and sell in the spring. Trying to get down to 2 or 3 boats.:banghead: :banghead: :banghead: :banghead: :banghead:

 

[DBLOCK]

I wonder how hard it would be to remove the bulkhead and swap it with the '95 bulkhead...?

Think I'll head back out to the garage to see it the parts fit & play with my heat gun...

 

[Matt_E]

It will be impossible, unless you cut off the top deck.
Trust me - it will be MUCH MUCH MUCH easier to just buy the right housing.

 

[Matt_E]

I think I have an extra housing for that year square you can have for shipping.

 

[DBLOCK]

I just got back in from the garage and think I agree with you - all that epoxy will take some doing to - undo...

If you can guarantee the housing is in otherwise good shape and it will fit the '91 hull, I'll take it... I think my email is enabled on this website - or send me a PM & we'll figure out how much this will cost...

Where in the PNW are you?

Dennis

 

[Matt_E]

I am in Eastern WA...PUllman area.
The housing itself is alright, but you will need bearings, seals, shaft

But hey, it's free. You might put a wanted ad out for a complete assembly. They usually go for around 75-125

 

[feartheride]

Hey I need a round nose one. I think I have a square If your interested I'll trade you and supply you with new bearings for housing and pump

 

[DBLOCK]

That's about what I paid for my complete, rebuilt midshaft assembly...

I wonder if I can swap the guts out.

I see feartheride just posted something about a trade. Matt_E has my full attention at this point until I figure I would be better off just trading for a complete assembly...

I am in Eastern WA...PUllman area.
The housing itself is alright, but you will need bearings, seals, shaft

But hey, it's free. You might put a wanted ad out for a complete assembly. They usually go for around 75-125

 

[Matt_E]

You would be better off trading the whole assembly. Otherwise, you'd have to press out the shaft out of yours, press out the bearings, and most likely get new seals (they're inexpensive though)

 

[DBLOCK]

Looking on the Yamaha parts catalog right now... There's a part number difference on the short shaft - Does anyone know what changed? The picture on the parts diagram shows the shafts looking different, but exactly what is different (besides what looks like a relief in the center) I can't tell. Anyone know what changed?

The local NAPA will pull the bearings off and press new ones on as a courtesy. No worries there.

This is making me wonder if I'm going to have problems installing the 61X setup into this '91 hull... Am I going to run into problems with spacing everything?

 

[Matt_E]

There is a difference. The 90-93 shaft has smaller diameter threads for the coupler.
That means you cannot put a newer style coupler on it or vice versa. It's not a big deal, as long as you stay consistent.
You can couplers for very little money (comparatively)

 

[Crab]

Go on Dennis, tell them its a 760-61X.....oops.

 

[DBLOCK]

Well, the midshaft assembly bolts right into the '95 hull - the bulkhead is correct for this assembly...

After thinking about it some, the bottom case half is the same between my 650 and this 61X setup (I'm pretty sure). I guess the only spacing issue would be the engine mount piece that I bolt to the rubber motor mounts. Guess If I had a problem here (using the 650 midshaft assembly), I'd just get the 650 engine mount? To much to think about right now.

I'll verify the pump assembly will fit onto the hull in the morning, then double check that it will mate up to my '90 650 midshaft assembly. Lots more to do before I'm done.

 

[DBLOCK]

Oh yeah! 760 big bore...

Guess I don't want the entire 650 assembly then & probably even want to go with billet couplers...?