New Here.. 1986 Sea Swirl Spyder Sport needs some love.

[Keaton]

Hello all,

So I bought a 1986 Sea Swirl Spyder Sport 178. It has a Chevy 5.7L with a OMC stern drive. Not sure if I have a Cobra or a King Cobra.

I need to rebuild the stern drive/lower unit. not sure what I OMC drive I have, after 29 years the sticker on the side is gone
story goes like this:
I took the boat to the lake, started it on the ramp made sure it would start, put the plug in, etc. I backed the boat into the water and it would start or even turn over. So I pulled the boat out of the water and got off the ramp (didn't want to block the spot). Once it was out of the water and in a parking spot we were messing with it. the starter was trying to turn the motor over but something was binding the drive line, the torque was moving the stern drive. we were playing with it, putting it in and out of F & R, trying to debug the problem. I hit the starter again and there was a bang and the motor turn over and started running. it would go into F & R and run fine, there is now a bad bearing noise in the lower unit and if i put my hand on the prop and spin it (and hand on the lower case) it doesn't feel smooth... so clearly something is broken... might be related to finding an unmarked rock and bending the brand new 4 bladed prop....


I want to add exhaust through the transom or side and not go through the bellows, help the motor breath. Is it as straight forward as it seems? what about losing structural integrity to the transom from drilling out 2x 4" holes? There is very limited room so that is why I was thinking going out the sides, but that looks like i would have to cut through 6-8" of side (guessing it is some sort of buoyancy adder).

it needs a few other things, new blower motor, find the lose ground that causes the instrument cluster to die then come back depending on what wave is hit, new throttle/gear selector/trim handle.

bigger long term things: interior & paint

 

[southkogs]

Welcome aboard Keaton: '86 was the last year for the full mechanical Stringers. Not sure if the Cobras were out just yet. What color is your drive? and do you have a big rubber boot on the transom where the drive passes through? Would kinda' look like this (not the same though, my drive is older):


If your drive was tilted up, the grinding noise you heard mighta' been your ball gear. But that depends on what drive you have.

 

[Keaton]

The drive is black, I know its either a Cobra or King Cobra not sure which one.

there is a big bellows for the drive shaft and a smaller one for the exhaust and a hose for the water pump

 

[bruceb58]

You have a regular Cobra

 

[Keaton]

Thanks, I just figured that out after poking around the forums and the stickies. where can i find the model number? So when i go to order parts i know what to get

 

[bruceb58]

Well, it originally was on a sticker on the thermostat housing.

BTW, you should read this site:
http://www.hastings.org/~stuart/cobra/

 

[jerryjerry05]

htthttp://www.boats.net/parts/search/OMC/SternDrive/1986/574AMKWB/parts.html
Here's a diagram and the parts break down.
The best bet is look for a lower unit for the 4.3 5.0 or 5.7 should be the same.
It takes special tools to fix anything on these. So doing it yourself is out.
There are some places that rebuild and aren't real expensive.
This site sells them.$3800 for the whole drive.
The unit you have is the Cobra.
The King Cobra was the big block in 87
Then they started putting the KC sticker on a BUNCH of motors.
Even the 2.3 4cyl got the KC sticker.

Drilling holes for the exhaust isn't that big a deal.
The stringer mounts and the transom are plenty strong and a couple of holes won't hurt.
Just make sure they aren't too low.

 

[Bayou Dave]

"I took the boat to the lake, started it on the ramp made sure it would start, put the plug in, etc. I backed the boat into the water and it would start or even turn over."

Did you start it on the ramp with a water hose ands muffs?

 

[Bondo]

"I took the boat to the lake, started it on the ramp made sure it would start, put the plug in, etc. I backed the boat into the water and it would start or even turn over."

Did you start it on the ramp with a water hose ands muffs?

Ayuh,..... I caught that too,..... Welcome Aboard Keaton,....

Boater Rule, #1,... Never start a boat motor, without supplin' Water to it,....

You've no doubt burnt up the impeller, if you just stated the motor in the parkin' lot,....

 

[Keaton]

htthttp://www.**********/parts/search/OMC/SternDrive/1986/574AMKWB/parts.html
Here's a diagram and the parts break down.
The best bet is look for a lower unit for the 4.3 5.0 or 5.7 should be the same.
It takes special tools to fix anything on these. So doing it yourself is out.
There are some places that rebuild and aren't real expensive.
This site sells them.$3800 for the whole drive.
The unit you have is the Cobra.
The King Cobra was the big block in 87
Then they started putting the KC sticker on a BUNCH of motors.
Even the 2.3 4cyl got the KC sticker.

Drilling holes for the exhaust isn't that big a deal.
The stringer mounts and the transom are plenty strong and a couple of holes won't hurt.
Just make sure they aren't too low.

the link doesn't show up.
$3,800 is way more then I paid for the boat

if I do the exhaust out the transom it will be pretty low. that's the only open spot there really is. the power steering rack is in the way on 1 side. I will take pics and post them to get your guys feed back.

"I took the boat to the lake, started it on the ramp made sure it would start, put the plug in, etc. I backed the boat into the water and it would start or even turn over."

Did you start it on the ramp with a water hose ands muffs?

correct

Ayuh,..... I caught that too,..... Welcome Aboard Keaton,....

Boater Rule, #1,... Never start a boat motor, without supplin' Water to it,....

You've no doubt burnt up the impeller, if you just stated the motor in the parkin' lot,....

I didn't think about the impeller, I was more thinking the motor would be fine for 10-15 seconds without water in it. I was starting it long enough to make sure it would idle and stay idling then killed it. if I run it out of water for any amount of time I put the hose and muffs on it. The impeller dry starts even with the drive in the water, takes a few seconds for it to pull a vacuum and water up to it. I will inspect it

 

[bruceb58]

Don't run it all without water.

When the drive is in the water, the impeller is in the water. It never dry starts.

 

[Keaton]

numbers on the transom mount

whats the cut purple wire?

the back, the power steering is about there the rear swim platform is on the drivers side of the boat

 

[jerryjerry05]

The adding thru hull isn't really a help.
It just makes it louder.
You can add hoses and elbows to direct the exhaust to any place on the transom.
You can add mufflers to keep it quite.

 

[bruceb58]

Curious why you would want to do thru hull exhaust.

You are going to have your hands full getting the drive to work properly. Personally, I would tackle that first since you will be spending big $$ doing that.

 

[Keaton]

I want the through transom exhaust for that nice V8 sound and to help the motor breath. The Y pipe takes 2x 4" exhaust and brings them down to a single 2.5" then through the bellows and out to prop. pretty restrictive

 

[bruceb58]

Having a more open exhaust does not mean you will have more power. A properly tuned exhaust system actually has some back pressure.

 

[Bondo]

I want the through transom exhaust for that nice V8 sound and to help the motor breath. The Y pipe takes 2x 4" exhaust and brings them down to a single 2.5" then through the bellows and out to prop. pretty restrictive

Ayuh,.... The restriction/ choke point in marine exhaust is the Manifolds,.....

Until ya go to full/ true Headers, thru-hull is a waste of time, 'n money,.....

 

[Keaton]

I'm going to be removing my stern drive this weekend, doing a tear down to see whats wrong

any tips or suggestion?

if my lower can be saved i want to replace any component that will ware out (all bearing, thrust washers, seals, etc)

where is the best place to get replacement parts at?


I also want to do a gimble bearing & bellows, where is a good place to buy a complete kit?

here are some kits i found
http://www.amarket.com/imc1000.htm

http://www.sterndrive.info/transom_service_kit.html

 

[Keaton]

numbers on the transom mount

these numbers don't show up in the user manual anywhere

 

[Keaton]

I'm at the hardware store looking for the lifting eye bolt. The manual says 112x13 thread, but that's not a bolt here. Does anyone know the correct thread pitch for this