1986 Mariner 3697- first spring launch/splash

[MrMojoRisin]

Thanks Viper, is there any good reference material/video's you could suggest on doing a raw backflush? Should i be doing that with the closed side too? Coming from outboards, these things are a bit foreign to me.

[bud37]

There are a number of marine grade products designed for fresh water flushing and being able to provide water so you can run your engines on the hard without damage. Many variations in quality and price so do your homework. Lots of videos nowadays.

You can even cobble some up if handy. Makes spring start up less stressful when you know the engines are tip top before getting to lift in....tune ups/impeller changes etc.

I installed fittings to achieve this on all my inboard boats.... when you get to lift in just hit the key, no surprises. ......

[Viper]

Source of the post Thanks Viper, is there any good reference material/video's you could suggest on doing a raw backflush? Should i be doing that with the closed side too? Coming from outboards, these things are a bit foreign to me.

I'm sure you can probably find something on YouTube. In any case, the end of the circuit will be at the exhaust manifolds. You can start there and it should flush through the raw water side of the heat exchanger and the U cooler and come out at the raw water pump. You'll have to remove the outlet hose at the pump. This might also flush out impeller pieces that might be trapped from a previous impeller failure if that's happened in the past but never followed through with a back flush. You shouldn't have to do the fresh water side (coolant/closed side), it wouldn't hurt to test the coolant and check it's condition/colour, rating though. They should have checked that at winterizing time but you might want to check it yourself with a refractometer and record your reading, then compare it to the reading you'll take at winterizing this year. If the reading worsens drastically, you may have an exchanger leak. This is also worth doing shortly after commissioning a couple of running hours later in case they didn't winterize her properly. Pressure testing the closed side will also tell you if there's a problem.

[MrMojoRisin]

Source of the post Do the sea cocks all operate freely?
All the fluids full?
Once it's splashed, check all through hulls and packings for leakage.
Keep some tapered plugs on hand in case a through hull fails.
Start the engines and make sure you have water flow or the exhaust. Same with genset. You may have to burp the strainers.

Sorry for all the additional questions but figured i'd lump them all into this general repair thread. I'm replying to Fred's post, as i know he has the same model as we do, but anyone is welcome that knows the answers.. We're making some progress but i'm having issues finding a few things.

1- Do you know where the fwd bilge pump is? I looked up front, below the front berth, but couldn't see much. Am i just not getting down in there far enough? Figure i should be certain both are operational before launch.
2- Wanting to confirm the fuel sender in the port/aux tank is functioning correctly, and check fuel level/quality but can't see it from the back deck hatch? Wondering if there is an access under the sofa that allows access to more of the top of that tank. Just ran out of time on our last trip and forgot to look on the way out. Also does anyone know the fuel capacity of each tank? The literature i have says fuel capacity is 274 gallons, but doesn't specify how much each tank holds.
3- Fuel guage selector switch on my boat is always in the middle. I can toggle it toward the port or starboard settings, but it springs back to the middle if i don't hold it left or right. Is it by default always in the middle, or is my switch bad?
4- On our short sea trial, the boat idled and ran great up till about 2600 rpm, but port motor seemed to bog, cough & sputter when trying to go any further. Previous owner said he thought the fuel filter needed replaced, which i have on the list to do, but I suspected it was a timing/advance issue. I confirmed it this weekend after pulling the cap & checking the rotor. Either the springs are broken or it's too corroded to allow it to advance. The big dollar question is, can that distributor be replaced without lifting the back deck. It looks like it might be close, but I didn't have a spare distributor to measure to double check.

Any insight on any of these items would be appreciated.

Thanks in advance,
Eric

[waybomb]

1) No forward bilge pump. Aft and mid. I installed a forward bilge myself since this boat leans forward a bit and I always had water. I jammed it in next to the fresh water pump just aft of the bed.
2) yes. Remove the cushions and you'll see the access covers
3) switch springs to center. Same thing was on my 2807 and 4207
4) yes you can pull the distributor no problem.

Also, you have 2 fuel filters. A cartridge near the back of the engine plus the one in the carburetor. I also installed two large racor had fuel filters ahead of everything else