4.3 MerCruiser vibrations 1000-1400 RPMs

K

konrad

Cadet
Joined
Jun 13, 2006
Messages
8
Hi everyone,
I just pick up a Larson with a 4.3 aplha one and even if I'm just using the throttle, I get vibrations from about 1000-1400 RPMs, same when it's in gear. Is that normal? My outboard had less vibrations than that. Any opinions will help,
Thanks
 
180shabah

180shabah

Rear Admiral
Joined
Mar 26, 2005
Messages
4,995
Re: 4.3 MerCruiser vibrations 1000-1400 RPMs

What year is is??

I believe it was '91 or '92 when GM added the balance shaft to this engine.
 
Don S

Don S

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Aug 31, 2004
Messages
62,321
Re: 4.3 MerCruiser vibrations 1000-1400 RPMs

93 was the first year Mercruiser used the 4.3 with a balance shaft. The old ones did vibrate like that.
 
K

konrad

Cadet
Joined
Jun 13, 2006
Messages
8
Re: 4.3 MerCruiser vibrations 1000-1400 RPMs

Thanks guys
so that's normal, I'm guessing.
Is there any grease fittings on the shaft?
BTW, it's an 89
 
180shabah

180shabah

Rear Admiral
Joined
Mar 26, 2005
Messages
4,995
Re: 4.3 MerCruiser vibrations 1000-1400 RPMs

Grease fittings on what shaft?

Balance shaft is internal to the block, so no fittings, But you have an '89, so no balance shaft.
 
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