Help on 1986 merc inboard) 3.0 140hp

[Lee Emerson]

I took my boat in for service beginning of May to have oil changed, lower end and tune up. I got it back 2 weeks ago and this past Friday I tried running it hooked up to garden hose. After trying to start it, I heard a loud pop! From there it was down hill. Would not start or attempt to start. So, Sat I brought it back to the place I had it serviced and they called me back today and stated that the oil pump gear and distributor gears have basically broke. Now I have worked on car engines before and a boat motor is basically the same. The boat ran sluggishly before bringing it in for service because of the winter and supposedly the boat ran for the repair shop. Although when I get it home it breaks. I do not know if this dealership thinks I have a big "S" on my forehead, But I do not find it to be a coincidence that as soon as I get it home that this all happens instinantly. Any feedback would be appreciated because they are telling me that they need to replace oil pump and distributor and it will cost me $1200, although I feel that they are to blame because they would not even let me see the boat run before I left.

 

[04fxdwgi]

I took my boat in for service beginning of May to have oil changed, lower end and tune up. I got it back 2 weeks ago and this past Friday I tried running it hooked up to garden hose. After trying to start it, I heard a loud pop! From there it was down hill. Would not start or attempt to start. So, Sat I brought it back to the place I had it serviced and they called me back today and stated that the oil pump gear and distributor gears have basically broke. Now I have worked on car engines before and a boat motor is basically the same. The boat ran sluggishly before bringing it in for service because of the winter and supposedly the boat ran for the repair shop. Although when I get it home it breaks. I do not know if this dealership thinks I have a big "S" on my forehead, But I do not find it to be a coincidence that as soon as I get it home that this all happens instinantly. Any feedback would be appreciated because they are telling me that they need to replace oil pump and distributor and it will cost me $1200, although I feel that they are to blame because they would not even let me see the boat run before I left.

Engine is indeed basically an auto engine. That 3.0 (181 inch) actually started life as the old Chevy II Nova 153 inch 4 banger.

Pretty hard to give any advise based on "I heard a loud pop". Could be any number of things.
Does engine turn over (spin)?
Where did the "pop" come from? Starter? Carb? Metalic noise? (pop could have been thru carb, as timing went out the window if dist gear grenaded itself)
Pull dist cap off and spin engine w/ starter. Does the rotor spin when engine does?
Can you turn distributor rotor by hand with distributor cap off?
When engine spins, does it build oil pressure?

So many questions........ But, as you are doing, I would question what was done by shop and why engine does not run on first
try when getting it home. PS: It's not very common to have the distributor gear grenade itself on those motors. It's usually an oil pump
problem that causes them to self destruct... I've seen it happen a couple of times when something gets past a crappy pickup screen and jams the oil pump.

 

[Docksidemarineservices]

I don't think the shop you took it to is to blame. Sh#t happens. Those engines are pretty much bullet proof. They usually fail due to in proper maintenance or freeze damage.