Wiring nightmare,

[Mpersicke]

Hey guys,

Morgan here, I’m out visiting my father in law Who lives on the west coast he’s got an old mercruiser ( unsure of the year ) serial number 4000493 according to the sticker on the valve cover. 165 hp 3.7L (230ci) straight six. serial number off the gimbal housing ( I’m assuming that’s the one for the leg ) is 55894.

looking for some wiring schematics, a service manual, and overall some insight.

Heres a break down of whats going on/happened.

de-winterized the boat a bout 3 weeks ago, was running well for three trips out crabbing/prawning. Since then we’ve been plagued with issue after issues first it was the carb issues, we pulled it apart cleaned it reset choke, was running real nice on land, then tried to go out fishing again just to have lack of power/stuttering at full load. 2500rpm was great, 3000 rpm and it dies out and acts like starving for fuel.

brought it home found the fuel filter clogged with crap, flushed the lines, new filter flushed again. Everything was working as it should. Before we headed out again, noticed the temp gauge not working, went ahead and bought a new gauge and sender, and installed.

Took the boat out, launched it, had no tach, no fuel gauge and no power to the trim tabs, lowrance or Radio. Continued to test the motor out for about 30mins, and once warm it starts dying out at full throttle again.

Now, we’re back home, mama bears not happy. And now our leg will come up but not go down.

hopefully someone has some insight on a service manual for this thing so I can start re-wiring it and hopefully not be hung by the mother in law.

thanks,
morgan

 

[alldodge]

165 hp 3.7L (230ci) straight six.

If its a 250 cu in is 1970-1981 is 165 hp
If its a 230 cu in is 1964-1966 is 150 hp

The manual is number 1 and can be found here
http://boatinfo.no/lib/mercruiser/manuals/mercruiser1.html#/0

 

[Scott06]

Check your fuel filter again, I suspect you will find it with debris again. You said you cleaned the lines , but Likely you have to drain and clean the fuel tank again.

power to the gauges would suspect when you wired up the temp gauge you interrupted 12 v supply to the other gauges. Typically these are all wired in series, likely something down stream didn’t get connected back up.

here’s a typical merc dash harness, this is generic by no means specific to your boat. Given the age and added components hopefully you are good with a volt meter. Typical issues are loose and corroded terminals, and poor wiring of added components.
https://www.perfprotech.com/blog/art...ness-schematic


Trim pump basic schematic https://forums.iboats.com/forum/engi...im-pump-wiring

i think this is the correct one for the age of your boat but year may help- older ones have single solenoid like an old ford start solenoid on the fender well , looks similar at least ...

if it is a later model year and has two solenoids the one in this thread is generically correct
https://forums.iboats.com/forum/eng...636454-wiring-diagram-for-motor-trim-solenoid

 

[Mpersicke]

It’s a single solenoid setup, I appreciate the heads up and the schematics.

the tag on the back of the boat says 165hp. So that’s my hope, I’ll look over the manuals shortly.

thanks everyone

 

[Mpersicke]

Thanks to you fine folks, the wiring is less of a mess, managed to get everything working for the most part.

it seems now that our down ram for the leg has decided to start spewing oil from the body

has anyone got a rebuild diagram for it?

what would cause the leg to go up but not go down? We have good motor works, found a broken wire off the motor which is why it wasn’t working before.

 

[nola mike]

If you have 2 solenoids then typically that or the wiring to one is suspect. Although "spewing oil" doesn't sound like it's going to help anything

 

[kenny nunez]

Exactly where is the leak on the ram? The tube may have a pinhole due to corrosion.

 

[Mpersicke]

It’s a single solenoid set up. As best I can tell the motor is running the way it should. We did have to replace the hydraulic lines that went from the pump into the gimbal housing a few days ago, but we bled the system and moved it up and down. Perhaps it’s got a bit of an air lock?

the oil isn’t spewing per say. But it’s leaking from the base of the ram body up through the threads. I’m assuming it’s blown a seal.

 

[Mpersicke]

Alright.

so the solenoids was good, replaced the leaking ram with a known good used one. Replaced ground wires, and now it’s much better.

as far as the motor, I’m at my wits end.

In the drive way, muffs on, the boat runs like a champ, I can bring it to 2500rpm without hesitation, and back down and it idle and runs fine. we launched the boat this morning, idles great in gear, once out of the harbour and give it the juice in gear, it stumbles and stalls, and surges.

what would be causing this? It’s got the bimetallic choke spring, I’m just on my way to get an electric one to replace it, as I think that’s causing the majority of the issues under load?

I’m not sure, any insight would be great.

 

[Bondo]

we launched the boat this morning, idles great in gear, once out of the harbour and give it the juice in gear, it stumbles and stalls, and surges.

Ayuh,...... Welcome Aboard,...... Sounds like a fuel delivery issue, could be anything from the tank, to the carb itself,.....

I usually start the diagnosis at the fuel filter, 'n go from there,......

 

[Mpersicke]

Thanks for the welcome, we replaced it about a week ago. Still having the same issues. I can’t see lm to upload the video.

 

[Mpersicke]

Ayuh,...... Welcome Aboard,...... Sounds like a fuel delivery issue, could be anything from the tank, to the carb itself,.....

I usually start the diagnosis at the fuel filter, 'n go from there,......

Wouldn’t it still stumble and surge on land at the same RPM if the fuel system was the culprit? It sounds 10000% different running on land then it does in the water.

beyond frustrating.

 

[alldodge]

When you run on land the motor needs very little fuel to rev high. IN the water the motor needs a lot of fuel to move the boat.

As Bondo said, start at the fuel filter and dump contents into a clear container to see if there is anything but clean gas.

If that's good, see if your getting 3-7 psi fuel pressure at the carb at idle and under load.

If that's good rebuild the carb

 

[Mpersicke]

When you run on land the motor needs very little fuel to rev high. IN the water the motor needs a lot of fuel to move the boat.

As Bondo said, start at the fuel filter and dump contents into a clear container to see if there is anything but clean gas.

If that's good, see if your getting 3-7 psi fuel pressure at the carb at idle and under load.

If that's good rebuild the carb

We’ve dumped the filter, a little bit of crud floating inside it, found a brittle fuel line, replaced that, sucked and blew through the vent line, that’s good.

picking up some clear line to check to see if it’s getting good flow, I have a vacuum gauge, so I’ll be testing the fuel pump at the same time.

 

[Mpersicke]

God. If it isn’t one thing it’s another with this damned boat.

blew another trim ram, this time it was the opposite side.

also, fuel pump took a crap too.

just can’t win.

anyone wanna buy a boat.

 

[alldodge]

What part blew, the seal or casing?