1970 Sportster Sportline Build Thread

[trav2210]

OK, after my last failed project, I finally have a new start. Its a 1970 Sportster Sportline. 17' with a 140HP Mercruiser and what appears to be a pre-alpha outdrive. Floors seem solid and ugly (carpet) and motor is...well...the head has been sitting off for a bit....

I hope to get this thing out on the water this summer (its already June) so I will be doing the interior mainly, and a quick restore on the motor until the season is over. Then it comes out to get a full rebuild... if it works out that way...

 

[trav2210]

 

[trav2210]

 

[trav2210]

 

[trav2210]

Got the carpet pulled today. There is a little damage to the floor around the ski locker, but very minimal. I can most likely get it out without tearing up the deck. Bilge area is oily, but very solid. Looks like I lucked out with this one.

 

[trav2210]

measured for carpet today. I will be looking at using the Home Depot "special" which is an Indoor/Outdoor carpet in light grey. Anyone use this stuff? I'm wondering if it will get hot with direct sun. It seems pretty thin and will be easy to apply. We'll see how long it holds up.

Started working on those rusty cylinders too. I poured some motor oil in to begin the process of getting these pistons to move. I took a brass brush to the cylinder walls to get the major gunk and rust out of the way. I need to move the pistons out of the way to throw a ball hone in there to really clean it up, but with no front crankshaft nut and a starter solenoid that just failed, I have no way to make this puppy turn over.

I know, I know, I should be pulling this motor and doing it the right way. And I will , it just needs to get through summer vacation beginning in the next 3 weeks or so. No time for a complete tear down, hone and decking...

 

[Bondo]

I know, I know, I should be pulling this motor and doing it the right way. And I will , it just needs to get through summer vacation beginning in the next 3 weeks or so. No time for a complete tear down, hone and decking...

Ayuh,.... Yer only foolin' yerself, if ya think that motor is gonna run,....

Pull the drive, then the motor, 'n rebuild it or replace it,....

Yer drive is an MC-1, 'n should be 1.98:1 ratio,....

 

[briangcc]

Started working on those rusty cylinders too. I poured some motor oil in to begin the process of getting these pistons to move. I took a brass brush to the cylinder walls to get the major gunk and rust out of the way. I need to move the pistons out of the way to throw a ball hone in there to really clean it up, but with no front crankshaft nut and a starter solenoid that just failed, I have no way to make this puppy turn over.

I know, I know, I should be pulling this motor and doing it the right way. And I will , it just needs to get through summer vacation beginning in the next 3 weeks or so. No time for a complete tear down, hone and decking...

You can with the motor out of the boat. You'd use this to do it: https://www.summitracing.com/parts/sum-900178

And since it's out it really should go to a machine shop for a dip, probably bore & hone, and check the head surface - all that looks mighty rusty and unlikely to seal properly. Running it without doing that work is just asking for trouble.

 

[trav2210]

I wish I had the time.

I'll be slowly moving the pistons down in the bore to see how far the rust travels. If it stops at the current piston line, I'll drop the piston down low enough to hone out the rust. Definitely a redneck fix, but it will get by for now. This motor will eventually get a full teardown for bearings, boring and decking in the winter.

I've already cleaned up the block deck and checked with a machinists straight edge and have almost no warp or low spots. I guess the pictures make it look a little worse...

The head had some low spots. Since it’s off, it’s going to the machine shop for a complete head job and mill.I'll probably have the intake/exhaust mating surfaces milled as well.

No question about it, this motor will run. Just a question of how big I will need to bore the cylinders after summer vacation is over...ugh

 

[trav2210]

Thanks BONDO for the heads up on the drive model and ratio. I got lost in all of the serial number searches to know if i'm right or not.

So far I've obtained parts manuals through these guys.
https://www.mercurymarine.com/en/us/parts-and-accessories/parts-catalog

This has been a decent source so far. I hope all of the part numbers are relevant to the rest of the old interweb.

Anyone know of where to get an actual manual for the boat. I know Sportster MFG CO is out of California, but literature seems to be non existent...at least for boats.

 

[ezmobee]

Anyone know of where to get an actual manual for the boat. I know Sportster MFG CO is out of California, but literature seems to be non existent...at least for boats.

Typically they don't exist. A factory service manual for your specific motor/drive are the best you can do really.

 

[trav2210]

Copy That.

Drive will be coming off today or tomorrow. I filled the exhaust pipe with water to see what kind of condition that system was in, and I'm pretty sure I've got at least 1 cracked bellows. Might as well do them all while I'm at it. That should allow me to inspect the U-joints, shift cable and everything else while i'm in there.

Do you guys know the bellows kit PN for this drive? I'm looking to put a new bearing in there while I'm at it and would like to find a kit with it and all the bellows gaskets and clamps.

 

[trav2210]

With the carpet up, I've been working on scraping the deck clean of any carpet glue or remnants. I plan to fill the old seat holes with 5200 and then paint the entire deck. Then I will follow up with carpet on top of that. Any issues in my thought process?



Also, started looking at the transom assembly and noticed I've got a few wires that have seen better days. Specifically these two that enter the transom. What are they?

 

[briangcc]

Not sure but that looks like bare copper wire to me that's been exposed to a lot of moisture. Trim maybe??

Better question though - what's with the white extension cord (bottom of your engine bay pic, just above the green wire)? Is that tapped into your wiring harness?? If so, you may have a much larger project on your hands as that certainly looks like redneck engineering to me and I wouldn't be putting 12V to the boat until I knew the wiring was good.

**I had Christmas tree light wire hacked into my classic Trans Am so I know all too well about redneck engineering.

 

[trav2210]

I wouldn't doubt that being extension cord. I've yet to even dig into wiring, but after seeing the exposed copper on those wires and others, I figured I'd start putting part numbers together and get them all at once.

On a bright note the head went to the machine shop today. Should have it back in a couple days. 160 for cleaning, pressure test, mag, valve job, seals and guides as needed.

I picked up the carpeting too and am finishing up sealing the deck prior to it going down.

This weekend I will be working the cylinders over...

 

[trav2210]

Well boys and girls,

After finding quite a bit of water in the oil pan, I've come to my senses and decided the motor is coming out. I've pulled the remainder of the wiring harness, and pulled the two rear motor mount bolts. Stern Drive came off, actually easier than I thought. Definatley some wierd stuff going on there. As far as the cause of water in the engine, I was thrown for a loop as this is a southern California boat that has never seen salt water or freezing tempurature. After looking at the head, the exhaust ports had a lot of rust in them. This lead me to the manifold. After looking further at it, I can tell its a pile of junk. Same with the riser. You can see a small hole in it.

MANIFOLD









RISER

 

[trav2210]

My plan going forward (besides the rebuild) is to not pull the front motor mount. I'll pull the 4 bolts that connect the motor mount to the front of the engine. Therefore not needing to go through the alignment process again with adjusting the the front mount. Engine should be out in the morning once I get off from work (nights).

Anyways, heres some pictures of the drive as it came off. Looks pretty good with the exception of that white stuff. I believe that is the water inlet, correct? U joints look good, bellows look good. Any way to easily inspect these for leaks? Bearing seems fine as well. Let me know what you all think as I've clearly been delusional about the motor to begin with...

 

[trav2210]

I've also just realized I've got a steering wheel that won't turn... More problems

I took off the bracket that connects the drive to the end of the steering cable and the drive moves just fine. No hold up there.

It must be the cable but this thing has a pretty old adjustable column. I believe it to be rack n pinion. Anyone have any input?

 

[trav2210]

Engine is out and on a stand. Doesn't look horrible. Probably could have gotten away with my original plan of attack, but it was so easy to pull anyways.

I throw a quick hone on the cylinders to see how they turn out. Rings were definitely stuck in cylinders 3 and 4. I couldn't drive them all the way out with wood, so a ratchet extension was used. It mar'd up the back of the piston a little.

That being said, this is and will stay with std pistons, but with the above condition after removal, and the Rings stuck in the pistons, I will just be putting new in since they come in the rebuild kit.

Is it true that you can use sbc pistons? I'm looking at rebuild parts and trying to maximize the dollar.

 

[trav2210]