Rattling sound 1984 Evinrude 50hp

[Bailey_B]

I’m a novice with outboards but enjoy tinkering if pointed in the right direction. Cruising back to the launch last Fall going about 3/4 full speed and all of a sudden loud rattling sound occurred. Fired it up back at home. First video: Idle shows rattling at idle. Second video: Low RPM seems to make the rattle go away when running on low RPM. Any ideas?

 

[jimmbo]

Welcome to iboats

You need to make a few more Posts before you can upload Pics or Videos

 

[Bailey_B]

Sorry, not sure what that means. Ask questions and I can try to provide more detail on my problem.

 

[jimmbo]

You claimed to have posted Videos. You can't do that until you have posted/replied a few times

 

[Crosbyman]

just click on his blue lettered words idle and low RPM

 

[flyingscott]

Pull the lower unit off and see if it goes away

 

[jimmbo]

just click on his blue lettered words idle and low RPM

I click, get a picture with a Play Arrow, click it, and Blank Screen...

 

[stresspoint]

back in the days of my experimenting with 2 stroke timing , my 55 did that just before it spat a rod out the side of the block.

 

[Crosbyman]

I click, get a picture with a Play Arrow, click it, and Blank Screen...

works fine for me....

 

[jimmbo]

It doesn't for me. God Damn Windows 11

 

[Ronniewhite]

It doesn't for me. God Damn Windows 11

Click on the down arrow at the top of the page and download it to watch it. It was doing the same thing to me but after I hit that arrow and downloaded it I could watch it.

 

[jimmbo]

Still no play. What Ever...

 

[Bailey_B]

Did a compression test. 130psi top cylinder, 100psi bottom cylinder. Checked the gear oil too. Oil was replaced in fall before winterization and is slightly milky already.

 

[racerone]

Motor needs work.-----Remove cylinder head for inspection.----Lucky you if it is a blown head gasket !!

 

[Bailey_B]

Took cylinder head off, bottom piston has some play in it. Bottom piston’s top dead center position is about 1/16” less than top cylinder. When I jimmy the flywheel back and forth when the bottom cylinder is in TDC I can hear slight clanking. Top cylinder in TDC looks and sounds good. Something messed up with the bottom cylinder connecting rod?

 

[racerone]

Your motor needs repairs.----Take it apart.