Cylinder Full of Sludge. 93 SL750

[Spendit_on_polaris]

Hello everyone, new to this forum with a post. Tried trading through all the posts and couldn't find anything. I have our old 93 Sl750 I am trying to get running. Replaced all the fuel lines, pump, rebuilt carburetors and tried to fire her up to no avail. Found out I have 75-80 psi on the cylinders. I probably should have started with that but had no idea what I was doing and where to start. So now I'm here. ALL 3 cylinders had sludge (gas/water/rust mixture) in them. Where should I start now? Any advise or pointers would be appreciated.

[xlint89]

Welcome to the Hulk.

That's not good. Start with inspecting the crankshaft. If that's all rusted you're in need of another. More specifically, the crank bearings. If those are rusted, you're on borrowed time. They may last 3 years, or they may last 3 minutes. No one knows. But when it fails, hopefully it doesn't take out anything else.

That cyl looks to be rusted pretty good. I would guess there is pitting from the rust which will cause low compression problems. So you might need to have the cyls bored oversize and buy pistons to fit.

Honestly, I'd be looking out for a cheap replacement engine.

[Spendit_on_polaris]

xlint89,

thank you for that. I went ahead and pulled the engine out. I am going to pull everything out and try to salvage as best I can. The oil and inside the crankshaft that has the same color as the picture above. How would I drain the oil out? Also, if I drain it and take everything out, am I going to have to "set the timing on the crankahft when putting it back together?

[ZMANN]

Setting timing is not a concern for this motor
but if you see rust at the crank like at the head then you better figure on a crank rebuild and see if you want to even proceed

[ZMANN]

if you want to inspect further pull the jugs and split the case

it is one of the easiest pwc motors to work on IMO

[Spendit_on_polaris]

Thanks.

Is the crankshaft something I can pull and clean off? Here is a picture of top. Working on splitting the case now.

[Spendit_on_polaris]

[ZMANN]

Chances are high that the bearings have been compromised and running a crank like that will lead to major failure in short order

you can pull and inspect but you likely need to have it rebuilt or replaced

[Spendit_on_polaris]

Crankshaft rebuilt or replaced? Also, still trying to split the case. Is there a trick to it and there are a lot of bolts down on the bottom. Just start unbolting?

[xlint89]

Honestly, I'd look for a used engine you can drop in. Then use yours for spare parts.

It's going to cost you nearly as much to bring that one up to par.

You can still go ahead and tear it down if you want the experience of disassembling it, but it's going to be faster, easier, and possibly cheaper to go with another engine.

If you plan on doing it as a winter project, have the time, and want a like new engine, then go ahead and rebuild it

I guess the question is, what are your intentions at this point?

[xlint89]

Crankshaft rebuilt or replaced? Also, still trying to split the case. Is there a trick to it and there are a lot of bolts down on the bottom. Just start unbolting?

The trick to getting the engine coupler off is to lock the PTO piston so you can remove the coupler.

The same goes for the MAG piston to remove the flywheel nut. And then removing the flywheel.

After that, it's just bolt removal.

[Spendit_on_polaris]

I am going to try and rebuild the the engine myself. Gives me something to work and do something I have never done. So my next question is this. I have taken all the bolts off the block to separate it. But I can not get it to separate. Any ideas?

[Spendit_on_polaris]

What is the engine coupler?

[xlint89]

How about posting a pic of what you have?

There's a couple things that can be holding it together.

It will be much easier if the engine coupler and flywheel are removed before trying to split the engine case.