VIBRATION FROM MY 86 EVIN.

[CATKRAZY]

Hi guys i have a problem with vibration from my engine at low idle speeds. i have a 1986 60hp evinrude outboard. i thought it may be carbs in need of cleaning and maybe rebuilding but i was also thinking it may be my prop. The prop has a slight irregular bend on one of the 3 blades my engine seems to get up and go no bogging down or stumbling when yu get into the throttle but like i say when you are at idle it seems to vibrate. I am in the process on changing transom wood now due to rot some areas were even rotted into the area near one of the engine bolts, so i dont maybe that could have been part of the vibration being felt too. any thoughts as to what it would most likly be causing the problem and if anyone thinks its the prop being bent causing the vibration how do i know what prop to replace mine with. i checked iboats and they had over a dozen different ones to choose from it seemed like. im new to the world of boats so the muliple diameters and pitches that are avalible get confusing to me. any info on any of these problems would be helpful

 

[WillyBWright]

Re: VIBRATION FROM MY 86 EVIN.

Look for numbers on the prop you have. Many times they're hidden by the prop hardware. If the vibration comes and goes with shifting, it's the prop. A bent blade can do it. They can be rebuilt cheaper than the price of a new prop, roughly a third to half. I'd also check for a bent propshaft. With the motor off and in neutral, just give it a spin and watch the shaft center for wobble. If you can see it, it needs to be replaced.

 

[CATKRAZY]

Re: VIBRATION FROM MY 86 EVIN.

Look for numbers on the prop you have. Many times they're hidden by the prop hardware. If the vibration comes and goes with shifting, it's the prop. A bent blade can do it. They can be rebuilt cheaper than the price of a new prop, roughly a third to half. I'd also check for a bent propshaft. With the motor off and in neutral, just give it a spin and watch the shaft center for wobble. If you can see it, it needs to be replaced.

 

[CATKRAZY]

Re: VIBRATION FROM MY 86 EVIN.

Thanks willyB for the info is the prop shaft a hard thing to replace? I have a service manual for my motor coming in the mail real soon so i was thinking i could probably replace that also if there is a wobble to it like you had mentioned. also the main reason i was wondering about prop replacement is cause im not even sure if the guy before me knew what he was doing when he picked the one he put on the boat. ive heard prop selection is important on your motor and i just didnt want to put to much faith in what the previous owner thought or did to it.

 

[WillyBWright]

It's a hard enough job. You'll need that manual.

The correct prop is the one that allows your OB to run at full recommended RPMs at full throttle with an average load in decent conditions. Here, a Tach is a critical thing to have. But there are other ways of reading RPMs such as using a timing light with a tach readout.