Running rough, starter working hard

CascoBay

Petty Officer 2nd Class
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Mar 13, 2010
Messages
194
2000 Volvo Penta 5.7L GS

I pulled the motor this past winter and replaced the starter, spark plugs, manifolds, risers, and drive coupler. I just got the engine back in the boat this week and I have the following problems:

Starting the engine is difficult. By that I mean the starter struggles to turn the engine over. Batteries are fully charged, and I had them tested (less than 2 years old also) and they came back fine. All electrical connections seem good. Sometimes the engine turns over normally like it always used to.

The other problem is the motor stumbles and idles roughly. I did a compression check while I had the engine out and all cylinders were right at 180 psi. Cap and rotor were replaced last season. I checked the firing order as well. The engine revs up very well it is just the idle is rough- it used to be smooth.

Thank you for any and all help.
 

Bondo

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Messages
71,082
Re: Running rough, starter working hard

2000 Volvo Penta 5.7L GS

I pulled the motor this past winter and replaced the starter, spark plugs, manifolds, risers, and drive coupler. I just got the engine back in the boat this week and I have the following problems:

Starting the engine is difficult. By that I mean the starter struggles to turn the engine over. Batteries are fully charged, and I had them tested (less than 2 years old also) and they came back fine. All electrical connections seem good. Sometimes the engine turns over normally like it always used to.

The other problem is the motor stumbles and idles roughly. I did a compression check while I had the engine out and all cylinders were right at 180 psi. Cap and rotor were replaced last season. I checked the firing order as well. The engine revs up very well it is just the idle is rough- it used to be smooth.

Thank you for any and all help.

Ayuh,.... Unless you removed, sanded, 'n Cleaned the wirin' ends, Seems ain't to good,...

The rough idle is probably the carb/ choke adjustments,...

Have ya set the Timin',..??
 

CascoBay

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Mar 13, 2010
Messages
194
Re: Running rough, starter working hard

I went around with a multimeter and checked the wiring. I am getting the same voltage at the starter as i am at the batteries.

Now the engine wont even start. Once I get it to start, I will check the timing with a light.

If I can figure out the starter laboring so hard problem (it may be the batteries- only showing 12.5v with no load) my understanding was I should be at 13-14.4v. I bet with a load it drops to 10 or 11 volts. Working on this right now.
 

Bondo

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71,082
Re: Running rough, starter working hard

I went around with a multimeter and checked the wiring. I am getting the same voltage at the starter as i am at the batteries.

Now the engine wont even start. Once I get it to start, I will check the timing with a light.

If I can figure out the starter laboring so hard problem (it may be the batteries- only showing 12.5v with no load) my understanding was I should be at 13-14.4v. I bet with a load it drops to 10 or 11 volts. Working on this right now.

Ayuh,... Yer checkin' Voltage, not Amps delivered,...

Did ya remove, 'n Clean the connections,..??
 

CascoBay

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Mar 13, 2010
Messages
194
Re: Running rough, starter working hard

What connectors are you speaking of? When I had the motor out the main harness pins are clean. The starter connections were clean when I replaced the starter. The battery terminal connections were clean when I pulled the batteries for testing. The ignition switch terminals are clean.

Not sure what else you mean?
 

CascoBay

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Mar 13, 2010
Messages
194
Re: Running rough, starter working hard

I will also mention that the ground lugs on the rear of the engine are new.
 

Maclin

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May 27, 2007
Messages
6,761
Re: Running rough, starter working hard

The starter may be experiencing kickback if the static timing is set too hogh, this is one of the reasons Bondo asked about the timing.

Can you describe the procedure used to time the engine?
 

CascoBay

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Mar 13, 2010
Messages
194
Re: Running rough, starter working hard

Understood. Cylinder #3 TDC on compression stoke, rotor pointing at #3 cylinder on cap when the distributor is dropped into position. I have not had a timing light on it yet (and my harmonic dampener has no markings) but I did have factory markings on the distributor which should get me ball parked.
 

CascoBay

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Mar 13, 2010
Messages
194
Re: Running rough, starter working hard

Timing was the problem. I set it while running and the starter no longer fights. Ran great. 2 hours later it wont start. I have not dug into it yet. Coil feels like it has oil all over it.
 
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