A few things

[timharper89]

First off, not sure if this is all in the correct subtopic. Sorry about that. I recently acquired a 1987 four winns sundowner 4.3 merc. I noticed it taking on water and found a tear in the drive bellows. I think I can figure out how to replace that from YouTube, but I found a few other issues. One is the screws holding the swim platform (only the two closest to the ladder) do not stay in. One catches and tightens, but it keeps unscrewing when weight is applied to the platform .The other (bottom screw) one just spins and seems to be stripped.
​​​​​​Second is I saw pink fluid in the bilge. Upon investigating, I traced it back to the trim tab reservoir. Not sure where it is leaking at the moment, but the area under it had lots of fluid. Any suggestions where to start? Tab motor is a bennett v351

Third is I found a pair of small (think speaker wire) red and black wires on the port side by the battery that don't connect to anything. I was able to trace them all the way back up to the dash area. They just went with all the other wires. The temp gauge doesn't function at the moment, and I wondered if that might be why. I'll attach pictures.

Fourth, I have a slight fuel (I think) odor coming from a small compartment to the bow side of the fuel tank. There is no odor in the engine compartment. I just cleaned the bilge as best as I could with dish soap yesterday. There doesn't seem to be fuel pooling anywhere at the moment. Any ideas here?

Fifth, last time I had it out, it started perfectly fine on the first crank very quickly. It then died idling. I started it a few more times, which were hard starts, and then it died idling again. This happened 4 times before I gave up and just put it back on the trailer. Started it again yesterday ,and it fired right up. It was in my yard, so I didn't let it idle (didn't have a hose but was just curious). Fuel filter? Pump? Should I run some Seafoam through it?

Sixth, power steering pump doesn't seem to work (pretty hard to steer). There is fluid in the pump JUST under the full line. Does this mean tth pump is bad?

Finally..not really something broken (I don't think). I have trouble getting out of the hole with a full load (we have to send people into the cabin to put the bow down). Motor is trimmed all the way down, trim tabs up (have tried many configurations, but this seemed to be the most successful). Max speed was around 40 on the Speedo with 3 adults. Max rpm was about 4200 this is WOT. It is less (32mph 3800rpm at WOT) with a full (6 adults) load. I'll post a pic of my prop. I'm wondering/hoping it is prop related. I believe it's 23 pitch. I'm new to this, so I'm not sure what it all means.

I'll attach pictures of other things as well. Thanks in advance for the help!

 

[Scott Danforth]

you need to have a mod move this to the Mercruiser forum

 

[timharper89]

I wondered where to post it since it has so many things from different areas

 

[Bt Doctur]

swim platforms are usually thru bolted not screwed , loose screws may mean a rotted transom
the bennet has a plastic res and 2 lines out the back, loose or cracked plastic hoses
red and black paired wires usually power something
test the temp wiring by grounding the wire st the sender, should go full scale
if you can smell it, its a leak. check all hoses, clamps, sending unit
check all fuel filters, fuel pump, anti-syphon valve
may need to grease the steering where it goes thru the guide tube, corrosion make it tight
prop is too large of a pitch if its actually a 23P, check the number on the prop

 

[timharper89]

Grounding the wire? Just put it to the block and the temp gauge should read full hot?

 

[timharper89]

Also definitely a screw..at least the one that tightens. I pulled it all the way out. I'll check the one one and in the inside to see if it goes all the way through

 

[timharper89]

It says "23p" on the prop ,so that's why I guessed it was 23 pitch. What pitch do I need on this boat? General purpose, we ski/wakeboard, just cruise ,etc. I'll check on all this and see what I come up with. Thanks for the input. As for checking for leaks ,there are no hoses near where I smell the odor. There is no odor near the hoses and no fluid that I can see. Should I put paper towel or something around the hoses and run the boat to see if fuel is leaking?

 

[Bt Doctur]

Grounding the wire? Just put it to the block and the temp gauge should read full hot?

If the wire goes to the gauge and the gauge is in working condition, Yes

Depending on your activity for that day, either a 14 x 17P or a 14 x 19P

 

[Bt Doctur]

If you can smell it, there is a leak. gas odor does not just appear .could be very old hose permeating thru the rubber

 

[timharper89]

Is this the temp sensor? If not ,can you point me in the right direction?

 

[timharper89]

Also, this is attached to the end of the red and black wires. Any way to tell what they went to if not the temp sensor?

 

[Rick Stephens]

Depending on layout, you may be able to replace the platform screws with bolts, or long machine screws and put a washer and nut inside.

The fact they are stripped begs the question if the wood is rotting in the transom. It might be worth the effort to drill a couple test holes into the wood from the inside. Don't drill through the fiberglass, just drill into the wood, lower down the better, and look at the shavings that come out. You can permanently fill those holes with 3M 5200. Any dark, wet or punky wood will tell you how the transom is faring after 30 years.

If the motor is running well, then the correct pitch prop is the one that allows the engine to come up to the correct RPM at WOT. I believe on your 4.3 that is 4400-4800 RPMs.. So you are a bit over propped at the moment and should bring it down as stated. I'd probably start at a 19 inch 4 blade Solas Aluminum from iBoats for the type of use I use my boat for - pulling wake boarding kids. Choosing a prop has a lot of factors, and there are a lot of choices. No one can answer the question exactly as to which prop you should get. Do read the stamp off the side of your prop and post it back. It will help a lot in getting better answers.

 

[timharper89]

Definitely not thru bolts on the swim platform. I see the through bolts for the tow rope loop, but nothing otherwise .Is there a way to fix the lose screws without a major job? The boat is old ,so I don't want to invest a ton into it. Just hoping it'll last a few years. On the gas smell, is there a good way to check where it might be? I see no obvious weak areas. Hoses don't look cracked, fittings are dry and tight.

 

[Bt Doctur]

Is this the temp sensor? If not ,can you point me in the right direction?

Yes, look for a tan wire up front. ground it to see if the gauge pegs

 

[timharper89]

I uploaded a picture of the prop stamp. It reads "48 7S124 A40L 23P. I'll see about drilling the transom tomorrow. If I find it is rotted, I guess what does that even mean? There is no flex in the transom when applying pressure to the outdrive. I'm doing want to dump money into this thing, and transoms are a big expense from what I've read.

 

[JASinIL2006]

Drilling holes like Rick suggests will tell you if your transom is intact or not. Tapping with a hammer or standing on the outdrive will not necessarily give you the information you need. (If your transom flexes when you put weight on the drive, the transom is REALLY gone.) Drilling some holes will either give you peace of mind or a realistic picture of what sort of problem you might be facing. In cases where safety might be a concern, knowledge is good, no?