Engine losing power at WOT and taking in water

[TSTitans]

Hello everyone! Just registered on here after a few weeks of reading tons of your posts and learning an immense amount about a boat we recently got. I'm well and truly stuck now, so I thought maybe you could help me. Completely new to boats and engines, so a little background on the repairs over the last 2 weeks in case I messed something up.

We have an 88 Mercruiser 3.0L with an Alpha One Gen 1 sterndrive on a 17ft Chris Craft Cavalier. We had an engine that after a season, winterized, wouldn't start well, and when it did, would stall when putting into forward or reverse. Replaced fuel filers, lines, cleaned the carb with cleaner, it idled a little better, still stalled when shifting into gear. Replaced spark plugs, wires, distributor cap, and rotor, reset the points gap (who knew all this even existed?!) now the engine runs smoothly, but still stalls in gear.

After much troubleshooting, and taking the outdrive off (that was intense), found that the shift shaft wasn't turning well, which in turn had damaged the shift cable, and the cut off switch was getting stuck . Replaced the shaft, the lower shift cable, shift plate assembly (had to move it off the engine since the old switch wasn't available any more and the new plate/kit couldn't mount there), and now it goes into and out of gear smoothly without triggering the cut off switch! Voila, we're running. Put the outdrive back on (hopefully correctly, it was tough going). Now we're running in the water! It was glorious.

So, we were on the lake for a full day, mostly tubing. Everything goes well, we take the boat out onto the trailer overnight, unplug, only a bit of water comes out.

Day 2, we launch, go to the marina and fill up. We smell horrible smell from the engine area as we run, not the normal slightly fuel like smell, but best described as the smell of steaming artichokes. About 10 minutes into tubing, the engine loses power at full throttle, like I'm backing off on the throttle but I'm not. We stop, turn off/on, it gets better for a bit, then again gets really weak and slow. We unload everyone and limp back to the launch to get out of the water. This time, when I pull the plug, the plug looked a bit damaged on the end, and lots of dirty, brown water comes out. I hadn't looked in the bilge before this, but the water just pours and pours. We pack up and drive home.

So, now I've checked the bellows, can see anything wrong. I'm almost sure the water inlet seal o-ring was on when we put the outdrive back on, since it kept wanting to jump out during the reinstall and we were watching it, and it wouldn't explain why we didn't have any problems on day 1. There is no leak into the boat when using a hose on the muffs, whether the engine is running or not. There is a small hole above the lowest of the 3 starboard bolts that mount the outdrive, I can't remember if it was plugged or covered by a washer before... We're a few hours from a lake, and the experience of removing and reinstalling the outdrive was a nightmare for me by myself, so I'm hoping I'm missing something simple that you guys could point me to before I do anything drastic again or have to drive a full day just to test it out in water.

Thanks in advance for your help and for reading my wall of text!

 

[Maclin]

What did the temp gauge show at that time? Almost sounds like a core plug or two rusted thru and finally let go, that would dump (rusty) engine cooling water right into the bilge. Did you look in the engine compartment while it was running?

 

[kenny nunez]

If you are wondering about the rubber ring my advice is to pull the drive . If it is not where it should be you will definitely get water in the boat. It is imperative to use a good grade of glue to hold that ring in place. Before you remove the drive either make a platform to support the drive or raise the tongue where the drive is supported on the ground or use a floor jack. The best way of course is with a shop engine hoist but I realize that not everyone has one. If water got into the bellows try to re grease the gimbal bearing to flush out the water as well as the universal joints.

 

[TSTitans]

Thanks for the replies!
None of the gauges are working at the moment. We got it launched into a local lake for a bit of running today. It had no leak for a time, but eventually started as we ran it for awhile, I think as the engine just generally got warmer. No leak, even at WOT for the first 15 minutes or so, then we saw water leaking in along the back wall of the boat, above the plug hole but from below a black plate on the wall... I'm not sure of the terminology, uploaded a picture here:
https://drive.google.com/open?id=0B3...hPZ2t3b2lQaHUw

 

[TSTitans]

Ok, got the down drive off. Can't tell if the O-ring wasn't in place to begin with or if it fell off during the removal of the drive, but when we could see in there with about 1" of gap, the O-ring wasn't in place and had dropped into the bell-shaped area. We'll fix that putting it back on.

Also, tried pouring water in various spots to see if we could find a leak. Only place we found was if we pumped water into the mid-sized bellows (behind the bell-shaped hole and the shift shaft), we got it pouring out drive from 2 holes near the boat. See this picture:
https://drive.google.com/open?id=0B3c0tUmL3OwNSHNGdkI3cFBzWjFzYmRlRHlzMk41Szc2REJR

Not sure if that's supposed to happen. Hopefully, it is, because otherwise it's not a seal or leak, it's a major hole.

 

[Benny67]

Ugh....looks like a transom leak. OR...your exhaust pipe has a hole in it...OR a leaking boot.

Unfourtunatly, I'd bet on the transom being the culprit. The age of the boat and the fact of the water leaking below the mount itself would make me believe that's the problem.

If you get lucky it could be the exhaust pipe or a bad bellow. But for the fact that you said that when you run it on muffs there is no leak would make me rule out a bad exhaust pipe.

There is the possibility of the u joint bellows or the shift cable boot being bad...however, the photo you show LOOKS like it's leaking from the bottom of the mount.

Meaning, if the leak was anywhere else it would be leaking above the mount...not below it.

Wiggle the outdrive and look at the transom mount from outside the boat when it's out of the water. If it's bad...well,I don't have to explain what you will see..it would be apparent.( the transom mount would wiggle against the transom)

 

[Benny67]

your engine issue is probably not related to the leak...

 

[Benny67]

also... it looks like someone already knew about the leak. In the last photo you showed with the hose in the exhaust port there is silicone caulk around the drive.

also, the holes that the water is leaking out of is the exhaust relief ports...it's to be expected to have the water pour out of there.

 

[TSTitans]

Thanks for the feedback! We found that the drive shaft only had one O-ring on it, and I think there are supposed to be 3 since there are 3 seats and what manuals we can find that match our parts seem to show 3 as well. Added the other 2 from a kit we had. We also fixed the inlet o-ring pretty securely this time.

Hopefully it's not the transom mount or the exhaust pipe/bellows either, since watching videos makes me think those repairs are bit out of my league I'll try the wiggling.

Let me know if you think of anything else.

 

[Grub54891]

Sad to say, but I think the transom is shot also. it will leak when under power from the torque of the drive pushing it forward. The sealer around the outside should not be there, it leaked before you bought it.

 

[Rick Stephens]

Thanks for the feedback! We found that the drive shaft only had one O-ring on it, and I think there are supposed to be 3 since there are 3 seats and what manuals we can find that match our parts seem to show 3 as well. Added the other 2 from a kit we had. We also fixed the inlet o-ring pretty securely this time.

Hopefully it's not the transom mount or the exhaust pipe/bellows either, since watching videos makes me think those repairs are bit out of my league I'll try the wiggling.

Let me know if you think of anything else.

Of note, those o-rings on the drive shaft do not keep water out of the boat. They should always be in a dry area on both sides. So they are insignificant.

What keeps water out of the boat -

*a good transom seal (this appears to be your main problem)

*a good gasket between drive and bellhousing

*a properly placed water passage o-ring (use grease to keep it in place while you install the drive)

*a good set of bellows, both drive shaft and shift cable.. (exhaust bellows is wet inside and out)


*everything else properly working without holes and corrosion.


The big square o-ring inside the bell housing is not supposed to keep water out of the boat. It only comes into play if one of the other gaskets or o-rings fails.


Sounds to me like you have both engine work to do and a transom inspection. Poke and prod with a screwdriver, even drill test holes in the wood to see if it is solid. You can fill test holes with 3M 5200 if the wood shows as dry and solid. It is NOT safe to run a boat with a rotten transom and or stringers. You can sink pretty quick with a failure there.

 

[Benny67]

Sad to say, but I think the transom is shot also. it will leak when under power from the torque of the drive pushing it forward. The sealer around the outside should not be there, it leaked before you bought it.

Good point...if you are on the early stage of it being shot THIS is when you would see it leaking. It might not be as apparent when there is no load on it.

 

[TSTitans]

Is the transom the back wall of the boat? Sorry if that's a dumb question. If so, and the wood is rotten, that seems like some major work. I'll look into it.

An update on what seemed to be related: we took it back out after working on all the o-rings and gasket and redoing the lower drive install with more support and care. We also added an automatic bilge pump. The boat ran great for a full day with a small seeping leak around the same place, but the leak was slow enough that after about 8 hours on the water, it still wasn't enough to get the bilge pump going and had only a small amount of water in the bilge. Seemed like that was it, but second morning, after a few hours of wakeboarding, we took her in to fill up on gas. Within about 15 min, then engine died and wouldn't even turn over. We ran the pump and it pumped out brown dirty water again...couldn't tell what the brown was (maybe oil...does gas make water brown?)

After a break of about 30 min, tried again to try to take it back to the launch to put on the trailer. It started up fine and got us to the launch, but within a few minutes, it died and wouldn't start up again.

So, seems there are 2 problems...an engine issue that seemingly only appears when the fuel tank is full, and pours brown water into the bilge from somewhere (the people taking the boat to the launch didn't watch to see where the dirty water came from), and the more continuous leak from the transom.

 

[Blueghost924]

Is the transom the back wall of the boat? Sorry if that's a dumb question. If so, and the wood is rotten, that seems like some major work. I'll look into it.

Yes the back wall is the transom. If your luck is like most boater's luck, soon you won't have to worry about the engine because you boat may sink from the transom housing failing all together. I wouldn't continue to run it in the water with an issue like this going on.