Merc 3.0L Engine Problems

[jregan5]

Hello All,

So I have a 1994 Bayliner Capri. Ive been having some problems with my boat for a while. They have been tolerable... up until now. The boat runs but she doesnt like to run at a low idle. I have the timming set at 8 degrees advanced. I tried to put it at 0 but it doesn't like that one bit. I have no idea how they have it set 1 BTDC. Anyways. When you give the boat gas it bogs down, and or shoots a flame out of the carb. I have the main jet set at 1.5. I tried goin both ways, from 1.25 all the way to 2.0. One of the problems we were having prior to this huge malfunction was it would stall when you would put it into reverse. Someone had tampered with the boat and I had noticed that they had set the firing order to 1-2-3-4. How long its been running like this, I have no idea. It is set back to 1-3-4-2 though. I also have always had the timming advanced. It ran pretty strong so I had no idea to check anything else. Do you think there is something wrong with the pistions or something internal to be causing these problems. I just dread having like a hole in my piston or something. Hopefully not, after all, it is called the Iron Horse.

I haven't done a compression check yet so I think thats my next step.

 

[Daddy5295]

Re: Merc 3.0L Engine Problems

Your book or top of carburetor should tell u the advance. For example 10 btdc means 10 degrees advanced. As for the wrong firing order I would start by changing out the spark plugs and looking at the distributor cap and rotor for corrosion and if cleaning doesnt help replace them.

 

[jregan5]

Re: Merc 3.0L Engine Problems

Thank you for the reply. Yea the top of the thing says 1 degree BTDC. Also i have changed the sparkplugs, rotor, cap, and ignition module. I wasn't getting any spark so I changed everything out. Still runs like scooter

 

[Don S]

Re: Merc 3.0L Engine Problems

Hello All,

So I have a 1994 Bayliner Capri. Ive been having some problems with my boat for a while. They have been tolerable... up until now. The boat runs but she doesnt like to run at a low idle. I have the timming set at 8 degrees advanced. I tried to put it at 0 but it doesn't like that one bit. I have no idea how they have it set 1 BTDC. Anyways. When you give the boat gas it bogs down, and or shoots a flame out of the carb. I have the main jet set at 1.5. I tried goin both ways, from 1.25 all the way to 2.0. One of the problems we were having prior to this huge malfunction was it would stall when you would put it into reverse. Someone had tampered with the boat and I had noticed that they had set the firing order to 1-2-3-4. How long its been running like this, I have no idea. It is set back to 1-3-4-2 though. I also have always had the timming advanced. It ran pretty strong so I had no idea to check anything else. Do you think there is something wrong with the pistions or something internal to be causing these problems. I just dread having like a hole in my piston or something. Hopefully not, after all, it is called the Iron Horse.

I haven't done a compression check yet so I think thats my next step.

After reading all that, is sounds to me like you have done absolutely nothing properly. Do you have an OEM manual, if not, here is one online you can use.
http://www.boatfix.com/merc/Servmanl/13/13covr2.pdf

Do the compression test like this
http://www.boatfix.com/merc/Bullet/97/97_25.pdf

Read the manual link I gave you and learn how to set the timing into base timing mode so you can set it properly.
When things are set up wrong on the 3.0L engines, they blow head gaskets, pistons, valves, crank shafts and basically destroy an engine.

 

[Daddy5295]

Re: Merc 3.0L Engine Problems

Well sounds like you have fixed most of what someone else messed up. I really dont think it would be something major. Sounds like a carb prob with all the other things you have already done. Especially with it back firing and the stall.

 

[jregan5]

Re: Merc 3.0L Engine Problems

I've done nothing properly? haha. It wasn't running at all, and now it is... I must be doing SOMTHING right. That first manual you sent me is just a cover page. I will buy a manual online tomorrow. That still doesnt answer my question though. When its timed right (yes i know how to time an engine) it runs like hell. Maybe I just have to do a compression check after all. Once i get that maybe I can get an answer. I doubt I bent a valve or blew a head gasket. I am worried about the pistons however...

 

[Don S]

Re: Merc 3.0L Engine Problems

That first manual you sent me is just a cover page.

Danged, can't even operate the link properly

Once you open the link, scroll down to the last page (manual outline) and put your cursor over the section letter you want to view. See the cursor change?
Click it and see what happens.

 

[jregan5]

Re: Merc 3.0L Engine Problems

Been a long day.... I got stuck on the river for 2 hours, cut me some slack.

 

[jregan5]

Re: Merc 3.0L Engine Problems

Hey what do you know.... doesnt work. It says bla bla bla.pdf not available

 

[Don S]

Re: Merc 3.0L Engine Problems

Well, you see the cover, and it works for me.
Good luck

 

[jregan5]

Re: Merc 3.0L Engine Problems

There I got it. It doesnt like Adobe Pro

 

[jregan5]

Re: Merc 3.0L Engine Problems

I always wondered what those 2 white wires were comming off the distributor were. haha. I am going to go through these steps tomorrow and let you know on the out come. Thanks!!!!