Mercruiser 3.0 starting problem

hunter530

Cadet
Joined
Sep 16, 2010
Messages
7
Hello fellow iboat members! I'm desperately in need on some advice.
Ok so here's what's going on. I just recently purchased a 19ft Bayliner with a 87-89? 130hp Mercrusier 3.0 2.5 liter I/O. With the weather warming up here in alaska, decided to get her up and running for fishing season. Problem is it doesn't want to start up. I have gone through the troubleshooting steps in the adults only section and have replace with brand new battery, spark plugs/ wires, slave solenoid, starter, fuel pump, oil, oil filter, fuel/water separator filter, Fresh gas in tanks. It now cranks and attempts to start. After a few turns of the key I could get it to run roughly for about 5-10 seconds before it stalls out. Checked carb and getting 2 strong fuel squirts for every throttle pushed but refuses to start. I'm thinking I should probably take out the carbs for a good cleaning but wanted to get some opinions before hand. Any thoughts, tips, would greatly be appreciated. Thanks in advance
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Mercruiser 3.0 starting problem

Are you using the throttle only button on the helm control, pumping the throttle a time or two before cranking and leaving the throttle up to about 1/4 to 1/2 throttle to start?
 

hunter530

Cadet
Joined
Sep 16, 2010
Messages
7
Re: Mercruiser 3.0 starting problem

Are you using the throttle only button on the helm control, pumping the throttle a time or two before cranking and leaving the throttle up to about 1/4 to 1/2 throttle to start?


Thanks for reply. I'll give that a try when I get off work today. Now is that the proper way to start these motors? This is my second boat and I'm learning as I go.
 

Don S

Honorary Moderator Emeritus
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62,321
Re: Mercruiser 3.0 starting problem

For carbed engines yes. They don't start like your car/truck EFI engine.
 

hunter530

Cadet
Joined
Sep 16, 2010
Messages
7
Re: Mercruiser 3.0 starting problem

For carbed engines yes. They don't start like your car/truck EFI engine.

Ok so tried what you said and it'll run for a few seconds then die again? What should I look into next?
 

grarrsmi

Seaman Apprentice
Joined
Jul 18, 2009
Messages
32
Re: Mercruiser 3.0 starting problem

Have you replaced both fuel filters? 1 going into carb and 1 at the bottom of the fuel pump.
 

hunter530

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Sep 16, 2010
Messages
7
Re: Mercruiser 3.0 starting problem

Have you replaced both fuel filters? 1 going into carb and 1 at the bottom of the fuel pump.

I didn't replace them but have taken them off for a visual inspection and both looked fairly new and not clogged. I took off carb to clean last and inspect and looks like new parts in there with little debris. Will put it back on the boat today and give her another go.
 

Don S

Honorary Moderator Emeritus
Joined
Aug 31, 2004
Messages
62,321
Re: Mercruiser 3.0 starting problem

Is the choke working? You have to leave the throttle up to 1200 to 1500 rpm for about a little while for it to warm up so it will idle. Are yo doing that or just going to idle position after it starts.

Here is a page from an owners manual.

start carb.jpg
 

hunter530

Cadet
Joined
Sep 16, 2010
Messages
7
Re: Mercruiser 3.0 starting problem

Choke is workin correctly had to make a little adjustments but looks good. So here are my steps that I took to start it. Any thing I'm doing wrong please correct me.

1. Press button on throttle only move it forward to the first stop, ( before engaging gears I suppose) then give 1-2 full throttles
2. Return throttle back to 1/2( this meaning out of gear)
3. Turn key to start
4. Engine cranks and starts
After i get it to start I just leave it at 1/2 and it will run for a few seconds rough then dies.

Am I doing something wrong here? Missing a step?
 

fishrdan

Admiral
Joined
Jan 25, 2008
Messages
6,989
Re: Mercruiser 3.0 starting problem

1. Press button on throttle only move it forward to the first stop, ( before engaging gears I suppose) then give 1-2 full throttles
2. Return throttle back to 1/2( this meaning out of gear)
3. Turn key to start
4. Engine cranks and starts
After i get it to start I just leave it at 1/2 and it will run for a few seconds rough then dies.

Am I doing something wrong here? Missing a step?

2. Return to 1/2 throttle, carb opened 1/2 way, 1/2 way between neutral and wide open. (EDIT: not in neutral)

After it starts, immediately back the throttle down to 1200-1500 RPM and let it warm up for a few minutes, then back it down to idle.
 

hunter530

Cadet
Joined
Sep 16, 2010
Messages
7
Re: Mercruiser 3.0 starting problem

Ok so got it to run. But now... It'll run for about 20-30 seconds when I lower the rpms but then it'll pop and die. I'm thinking maybe timing is either off or running to lean. Suggestions?
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Mercruiser 3.0 starting problem

Put a timing light on it and see.
 

fishrdan

Admiral
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Jan 25, 2008
Messages
6,989
Re: Mercruiser 3.0 starting problem

Ok so got it to run. But now... It'll run for about 20-30 seconds when I lower the rpms but then it'll pop and die.

How long was the engine run to warm it up, only 20-30 seconds then it pops and dies when backed down to idle. (sounds like normal symptoms for a cold engine backed down to idle too soon) If so, let it warm up longer, several minutes.

If the engine is warmed up and it pops and dies after 20-30 seconds at idle, sounds like it needs tune-up stuff, possibly carb or fuel issue. What's the engine idling at for those 20-30 seconds, should be 650-750RPM?
 

hunter530

Cadet
Joined
Sep 16, 2010
Messages
7
Re: Mercruiser 3.0 starting problem

How long was the engine run to warm it up, only 20-30 seconds then it pops and dies when backed down to idle. (sounds like normal symptoms for a cold engine backed down to idle too soon) If so, let it warm up longer, several minutes.

If the engine is warmed up and it pops and dies after 20-30 seconds at idle, sounds like it needs tune-up stuff, possibly carb or fuel issue. What's the engine idling at for those 20-30 seconds, should be 650-750RPM?

It was idling at about 1000-1200 rpms, dropping it caused it to stall out every time. At first it seemed like it was starving for gas but kept stalling out with no pop. After a few tries the "pop" starting happening and after that, didnt matter what rpms it was idling at as soon as it pops it just dies immediately. I have never used a timing light before in my life( embarrassed to say but true) so ill go look up some youtube videos to see how it works and will try. The gentlemen i bought the boat from did say i needed to adjust the timing to get her running right so ill look into that next. If all fails, ill probably get a carb kit and see if that helps out. Really don't want to take it to the shop but in the end if that's what will get me on the water i suppose i will. I just think its something really simple that i am crossing over and should be a simple fix. thanks for all your inputs and help, i do really appreciate it.
 
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