Motor vibrating on land

1

1989SeaRay

Recruit
Joined
Apr 22, 2009
Messages
4
I have a mercruiser 454 that I just finished rebuilding. I fired it up in my driveway and around 1500rpms the whole boat starts to shake. I do not have the drive engaged when this happens. Everything on the motor is basically new including the harmonic balancer. There is also a slight ticking that I haven't been able to track down yet. All of the cylinders are getting spark. Any suggestions on what could make the boat shake?
 
B

betayv

Senior Chief Petty Officer
Joined
May 13, 2008
Messages
706
Re: Motor vibrating on land

what about you the engine mounts are they new?. I will think about harmonic balancer but you said is new. check the mount.
 
BaileysBoat

BaileysBoat

Senior Chief Petty Officer
Joined
Sep 29, 2008
Messages
716
Re: Motor vibrating on land

Back to basics, but double check the firing order?
 
S

Shrub88

Seaman Apprentice
Joined
May 24, 2008
Messages
47
Re: Motor vibrating on land

1989SeaRay said:
Everything on the motor is basically new including the harmonic balancer.
Click to expand...
454 is externally balanced.

Did they give you a 427 balancer by mistake?

Was the flywheel changed?
 
1

1989SeaRay

Recruit
Joined
Apr 22, 2009
Messages
4
Re: Motor vibrating on land

It is a 454 8" O.D. Harmonic balancer. The flywheel was not in bad shape so I reused it.
 
Bt Doctur

Bt Doctur

Supreme Mariner
Joined
Aug 29, 2004
Messages
19,503
Re: Motor vibrating on land

double check the firing order by physically tracing each wire from the cap to the plug
Ask me how I know
 
deves3000gt

deves3000gt

Petty Officer 3rd Class
Joined
Mar 3, 2009
Messages
77
Re: Motor vibrating on land

I would have to agree with BT i did the same thing in my truck and at about the same rpm's it shook pretty good. and i only had two wires mixed up.
 
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