Engines smoking but running well

[Seif911]

Hey All,

So I finally got the boat out. It worked rather well however it was smoking quite a bit. I kept a close eye on the temp and the oil pressure, but both were consistent and good.

I did have 5 year old gas in the tank so that may be my whole problem, just not sure. Anyone have any ideas?

I also found I have a alternator problem on the port engine but there is no rush to fix that.

[waybomb]

White smoke, blue smoke, or black smoke?

White - steam
Blue - oil
Black - running rich

[Seif911]

It's all white smoke. There is water coming out of the pipes a the pumps look good. The temp on both engines are extremely consistent. I can't remember if it was 160 or 180 but looks good.

Maybe the centrifugal advance in the distributor is hung up? Got me?

[waybomb]

White smoke is steam. You may have a blown head gasket. You may have a cracked exhaust manifold, riser, or a bad gasket between the riser and the elbow.

You really need to find where this leak is. If it is in the exhaust, the very worst thing that could happen is water could leak after the engine is off, pour into a cylinder that has an exhaust valve open, you crank the engine, and something bends, like a rod. Time for new engine.

I would start at the exhaust manifold, riser, elbow. It's not that hard to do. Make sure you use high quality 6 point sockets on this project; rounded off exhaust bolts really, well, suck. You'll see the water trails/evidence after the assembly is disassembled.

With these leaks, the indicated temperature would be completely normal, since the leak is after the engine.

Exhaust parts are not that expensive, as compared to other things on boats, as they are a high replacement item.. Right now I can;t think of the name of the high volume outfit that sells them reasonably, and not China junk. I'll post later if I can remember it.

If you are not sure what you are looking for, google it and I'm sure you'll find pic, discussion, videos.

[waybomb]

Maybe the centrifugal advance in the distributor is hung up?

This would have nothing to do with smoke. But, it is easy enough to check.

You'll need a timing light. You'll also want to get some white paint, and paint the line on your balance and on the timing legend corresponding to your base timing.

With engine idling at whatever rpm is stated in your manual, first make sure you timing is where it is supposed to be. Consult your manual, and there will be a spec for total timing at a certain rpm. Have someone bring the rpm up to that spec, and with you and your timing light, see if the timing mark moves further away from TDC. Your legend probably wont go up to 30 degrees advance, but you can approximate it. If the mark isn't moving, you have stuck advance weights.

[Seif911]

Do you think it could be the bad gas making it smoke? I just pulled the water separators to mount new ones and they Have some nasty looking gas in them. Some varnish type and maybe a little water yet. I added some enzyme stuff to help the gas and water but I'm not sure how much it is helping. If the engines are still running, I will try to burn it up. I have to get rid of that 5+ yr old gas somehow.

[waybomb]

I think if there was that much water in the gas to smoke, the engines would not run.
But maybe the varnished gas, etc could.
Let's hope so.

There's no additive for gas that will bring it back. Don't waste your money.

If after the gas is gone, and you have fresh gas in there, it still smokes, I could loan you my borescope. You could remove the exhaust hose at the riser, and you could snake it down and look for signs of a leak or a crack without taking everything apart.

Good luck!

[Seif911]

Thanks Fred. I appreciate it. I put the new water separator/fuel filter's in tonight. I had to play around with the mounts but it's all good now. I also put the new fuel sensor in. It is really nice to see the gas level.

I checked the water coming out of the exhaust again, it is streaming well. That does not really show me if there are cracks or not, just that it is pumping well. At least we known that.

I'll keep a close eye on it. I would suspect that if it is the gas, you'd think it'd get better soon. I did put 97 gallons in, I doubt it mixed evenly, but probably sit on the bottom.

[CYO Admin]

I really doubt the gas being the issue. If it is white it is probably steam, and it's doesn't always mean a crack or leak. The cold waters of the lake, and the hot exhaust water will make steam as well. If it's similar on both sides that could be it just that. If it were me I would keep investigating but would hold off on tearing things apart just yet.

[Seif911]

It is very consistent on both sides. It seems something common to both or they both deteriorated at the same time. I checked the water coming to the engines and they each have their own thru-hull. It's weird. I can't remember for sure, but I thought it smelled kind of fuely. Like my new word?

Anyhoo, I will gather more info sometime this week when I run it again.