heavy mechinal vibration

[shipwreck]

1967 evrinrude 60 hp sport four

Back ground, carb rebuilt cleaned, engine di-caborned, new fuel lines, new prop,
-just took apart lower unit and checked ...ok


i had just rebuilt carb and have been adjusting low speed needles,
i got to where i thought was ok, idling, and shift ok
then i torn all blades off my prop, last week..... i replaced prop.
next week
new prop, close to old prop 10/1/18 x 11
put in water would start
need where set 4-1/2 turns out
i increased needles by slow adjusting
6 turns out
we took out
low speed heavy vibration, heavy or deep ... felt in driver set right up to stern of boat on bottom
we adjusted needles down little.
rough.. increased speed to work off high speed fixed jets
note : low speed needles are in good shape now wear
the boat ran pretty well
any thoughts?

what could this be?

 

[bgbass.1]

Re: heavy mechinal vibration

yor vibration could be coming from prop shaft possibly bent

 

[F_R]

Re: heavy mechinal vibration

At 4 1/2 to 6 turns out, those needles are set WAY to rich. No wonder it vibrates. It is slobbering on all that fuel. Beginning setting is 1 1/2 turns and you generally have to turn them in from that yet.

 

[Evinrude Boater]

Re: heavy mechinal vibration

Does it vibrate while sitting during fast idle or only while moving?

 

[shipwreck]

Re: heavy mechinal vibration

Evinrude Boater: vibration while moving

Fr: 1-1/2 that from needle all way seated?
then turn out or in from there?
i could get to start at 1-1/2 turns out - it start at 4-1/2 turns out for while
then would start we end up turn almost 6 turns from full seated to get motor to start.

??????????

 

[F_R]

Re: heavy mechinal vibration

That is totally abnormal. It should start and run at less than 1 1/2 turns out. I don't have any idea what's wrong with it, but something is.

 

[iwombat]

Re: heavy mechinal vibration

A leaky gasket would cause that for sure. So would a fuel line air leak. You can check for the gasket by spraying some premix around where the carbs mate withe the powerhead while running. If it perks up, you found your problem.

 

[shipwreck]

Re: heavy mechinal vibration

just found a rip in gasket on one side of carb only.

Can that make not start?
it is new gasket!

 

[Evinrude Boater]

Re: heavy mechinal vibration

If the gasket is ripped on one side then you're probably sucking air. Spray some mixed fuel on it like iwombat suggested. Is there fuel leaking out of the gasket already? Any air leak is going to make starting and running difficult since there's too much air entering the engine. Think of the carburetor as a mixing bowl of fuel and air. It's set up to precisely mix the two for proper combustion. If additional air enters the stream after the carburetor then that puts things all out of whack. No wonder you're cranking the slow speed jet out to make up for the additional air being sucked through the gasket.

 

[shipwreck]

Re: heavy mechinal vibration

While Thinking About New Plugs
Engine Has Ran In While 1-1/2 Oil Mix 50:1 And Half That
Plugs Are Oily After Running

Air Leak And To Much Fuel .....seem To Be Problem

It Did Run Pretty Good At High Speed 20-30 Mph

Dose Any Know Top Speed For This Model
1967 60hp Model 60733?

 

[shipwreck]

Re: heavy mechinal vibration

Anyone Here This Morning With Something Good To Apply
To My Learning?

 

[freddyray21]

Re: heavy mechinal vibration

top speed will depend on the boat you have it on. If you are talking rpms I don't have my manual with me but somewhere around 5500 I think.

While Thinking About New Plugs
Engine Has Ran In While 1-1/2 Oil Mix 50:1 And Half That
Plugs Are Oily After Running

Air Leak And To Much Fuel .....seem To Be Problem

It Did Run Pretty Good At High Speed 20-30 Mph

Dose Any Know Top Speed For This Model
1967 60hp Model 60733?

Not quite sure what all the above means. If it is fouling the plugs you either have too much fuel or not enough spark. Fix the air leak and see how it runs.