Leak on my Engine Mount?

Last August i bought a 1991 bayliner capri with a 120hp force. I ran it for 2 months and ran very well, we had fun with no issues. When I removed it from the water in October I replaced the starter and had it "winterized". I have been working on getting it ready for this summer, as I baby most of my things, I put a new blower unit it, a dual battery system, replaced the lower exhaust as it had a hole, and changed the oil on my leg ( which had a leaky seal and water in it).

I went for my first water test yesterday and after a few attempts it started fine but didn't stay running long. I did have fast idling problems last summer and hard starting. I think I need to adjust the idle screw so I am not overly concerned unless someone thinks I should be?

My real issue I had was when the motor was running I saw water bubbling up from what appeared to be the engine mount and some smoke coming out of the engine compartment. I understand it's an old boat with a 2 stroke which will smoke.

Does this make sense? Does anyone know what the issue is? I don't mind spending some money on this but will only go so far as I bought it cheap hoping to get as many summers as I can out of it.

Re: Leak on my Engine Mount?

Smoke inside the hood is usually a bad exhaust boot. #27 in the diagram below. This will affect low speed performance, more noticeable at idle, as the carburetors are sucking in exhaust. At higher speeds, the exhaust goes out the bottom exit by the prop.

Mercury, Mercruiser, Force, etc. - DRIVESHAFT HOUSING - 120 H.P.

Just need to take off the lower unit cover item #22. Remove 8 bolts (4 on each side) that run up vertically on the cover, and 6 bolts inside the cowl. Pretty easy to do.

Hardest part is usually getting that darn spring clamp #29 that holds the boot on back on with the new boot.

Re: Leak on my Engine Mount?

I just went out with the diagram and had a look but it seems the diagram didn't match my boat. The model number on the boat is 120LD91B.

Any thoughts on the potential leak?

Thank You

Re: Leak on my Engine Mount?




These are 2 pictures of the engine compartment. The second, close up one, shows where I saw water coming out from when the motor was running.

Re: Leak on my Engine Mount?

You sir, have a Force L-Drive.

It is not an outboard, and it is not a conventional i/o.
They were only made for a couple years, then abandoned.

The engine itself is a force powerhead, almost all parts are the same as the outboard version, except the crankshaft.

From the powerhead down, it is all, umm, different, until you get to the actual gearcase.

Re: Leak on my Engine Mount?

L-Drive is completely different. Sounds like you may have to separate problems?? Exhaust leak and a water leak.

May be the gaskets on the exhaust cover. Items 31 in daigram below. Water circulates inside of the exhaust cover. Maybe a cracked exhaust cover?

Mercury, Mercruiser, Force, etc. - POWER HEAD - FORCE 1991 120 H.P "B" MODEL L-DRIVE

Or maybe a loose clamp or bad hose on one of the water lines. Items 11 or 12. Maybe a leak in the exhaust bellows #7?

Mercury, Mercruiser, Force, etc. - EXHAUST SYSTEM - FORCE 1991 120 H.P "B" MODEL L-DRIVE

Or bad gasket between the spacer plate and engine block. Can't find a diagram that actually shows the gasket but there is one between the engine block and the spacer plate, item #2.

Mercury, Mercruiser, Force, etc. - SPACER PLATE AND STEERING TUBE - FORCE 1991 120 H.P "B" MODEL L-DRIVE

Re: Leak on my Engine Mount?

You'll need to start it and make it smoke.
Then really start looking and find the spot.
There are 3 bellows and 2 hoses that can be leaking.
Also the adapter plate can leak.
Fill out the profile,location? You might be close to someone who can help.

Re: Leak on my Engine Mount?

Than you all for the input. I spoke to quite a few people and was told to run the boat as having it out for the winter dries out the gaskets. I put it in the water and ran it for a while and have left it in. I checked to see if there was water coming in while the engine was running and it seem to get a little better over time so I am going to see if it seals itself. Something for me to keep a close eye on I guess.

I did have my bellows exhaust replaced last September and noticed some water coming out of the connection into the engine when I had the earmuffs on in my driveway. I checked the clamps and they could not get any tighter. I was told if it isn't coming into the boat not to worry. Any thoughts on this?

Re: Leak on my Engine Mount?

JMyro said:

Than you all for the input. I spoke to quite a few people and was told to run the boat as having it out for the winter dries out the gaskets. I put it in the water and ran it for a while and have left it in. I checked to see if there was water coming in while the engine was running and it seem to get a little better over time so I am going to see if it seals itself. Something for me to keep a close eye on I guess.

I did have my bellows exhaust replaced last September and noticed some water coming out of the connection into the engine when I had the earmuffs on in my driveway. I checked the clamps and they could not get any tighter. I was told if it isn't coming into the boat not to worry. Any thoughts on this?

Click to expand...

Sorry, supposed to say Thank you all for the input.

Re: Leak on my Engine Mount?

"I did have my bellows exhaust replaced last September and noticed some water coming out of the connection into the engine when I had the earmuffs on in my driveway. I checked the clamps and they could not get any tighter. I was told if it isn't coming into the boat not to worry. Any thoughts on this?"

If you are referring to the short hose that goes between the adapter plate and the exhaust housing, this is the main cooling water supply from the water pump in the lower unit to the engine block. I would be concerned about any leak here. Leaks usually don't fix themselves, rather this could be an indication of a potential problem. If the clamps are tight, then either the hose or the fitting is probably bad. If the hose fails, the engine will overheat very quickly possibly resulting in a blown engine.

If it's the longer hose that is attached to the fitting on the exhaust tube, this is where the cooling water exits the motor. Not a big deal...like you were told...no worry as long as it doesn't come into the boat.

Re: Leak on my Engine Mount?

Mercury, Mercruiser, Force, etc. - EXHAUST SYSTEM - FORCE 1991 120 H.P "B" MODEL L-DRIVE

It is item number 7 leaking at item number 8. I think I was told it was the water exiting the motor.

Re: Leak on my Engine Mount?

You should be good to go!

Re: Leak on my Engine Mount?

Thank You!

Re: Leak on my Engine Mount?

I took the boat out today and everything ran fine. I parked it for a bit and then went back out. 5 feet from the dock on my way out the second time, the engine was stuck in neutral. When I tried to give it gas the engine just revved and we didn't go anywhere. We started floating towards the shore so I trimmed the leg up. We paddled to deeper water and then the leg wouldn't trim down. When I push the trim up button on the throttle it goes up but when I push the down button I just hear a click from the engine compartment. Does anyone know what is happening here!!!!!!

Re: Leak on my Engine Mount?

I do have a bit of water coming into my boat, it bubbles up by the engine mount. I think I need a new seal between the mount and the boat. It is a very negligible amount which I will monitor to see if it gets any worse. If it does I guess I have a big job on my hands....