20 hp with excessive Vibration

MKD

Cadet
Joined
Aug 21, 2011
Messages
9
Just bought a new 2013 20 hp electric start Tohatsu and it seems to have a great amount of vibration. The dealer said he prepped and started the motor and found nothing unusual. I took it home and run it the river and the vibration can be felt thought the whole boat. Has anyone else had this kind of problem or am I just expecting a four stroke to run smoothly.

Thanks
 

WN2712NJ

Seaman
Joined
Jul 17, 2010
Messages
65
Re: 20 hp with excessive Vibration

Hard to say what is excessive... I have the same motor (08 vintage) and it is reasonably smooth, particularly at speed. On my 14 foot tinny, there is a definite resonance somewhere around 1500RPM and you don't want to stay there long. But that might be the boat as much as the motor.

Close to idle, it's ok, but not as smooth as my 1956 Evinrude Lightwin 2 cylinder. But that's not surprising given you've only got half as many spark plugs firing per rev of the crankshaft.

If you really want to feel rough, try any single cylinder 4 stroke kicker.

-dm
 
Last edited:

Sea Rider

Supreme Mariner
Joined
Sep 20, 2008
Messages
12,345
Re: 20 hp with excessive Vibration

Probably the sliding load of the steering is very light, check, adjust lateral bolt. Load should be adjusted bit heavier for engine to run straight at fast idle when you release hands from tiller. Other issues : engine clamp screws not adjusted tight, stern's bracket rod & bolt slighty loose, check.

Happy Boating
 
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