https://youtube.com/shorts/ktbCN43qW2g

The engine only shakes like this when it's idling. When I hit the throttle, it runs fine. I changed gas filter, oil and lower unit fluid but it still shakes on idle. Going to change spark plugs next but wanted to get you guy's thoughts on this.

Soft motor mounts. Normal

Oh OK. It's just that it never done it before until recently. It's hard to tell in the video but I feel like when it shakes like this, the rpm is dipping. My tachometer doesn't work so I can't see it for sure if that is the case. Every few seconds, it'll shake and feels like the engine may cut out.

wont hurt one bit to pull those plugs and look for an oddball like a wet, dry, or oily plug. from the sound of it, almost sounds like backlash from a dead miss or something rattling

Thanks. I guess I was on the right track after all. Will try to get those plugs checked/changed. Hoping that will fix the problem.

I was finally able to get my spark plugs changed today. Found out all 4 of my spark plugs were loose. I was able to remove them without the use of a ratchet. Installed the new plugs and engine seems to be running smooth and not shaking like before. Even on idle. Didnt get to run it all morning to test it but ran around for 20 mins and it seems good as new.

Your report begs the question as to WHY every spark plug was loose. I've run outboards for over 40 years and can't recall ever encountering a single loose plug.

I wonder as well. I never touched the sparks plugs since I bought the boat 5 years ago until now. Previous owner said he got them changed out. The plug on the bottom was so loose that it came out with only a couple of turns of the socket.

i've seen it. yard equipment, motorcycles, boats, cars. yeah, it doesn't surprise me. my conclusion would be they just weren't tightened properly. at this point, just glad it turned out ok for you cigga

Yep, and lucky you did not spit one. Maybe it is only Fords that do that.

You change plugs every FIVE years? (lemme guess....whether they need it or not?) Have you ever checked any mounting bolt for torque in this 5 year period?

No. I only checked the plugs cause I was trying troubleshooting the excessive motor shaking. Changed it cause I already purchased the plugs. The old plugs looked fine. I really don't know how often plugs on a boat should be changed. Other than visually inspecting the mounting bolts, I have not put a torque wrench or tighten the mounting bolts. I will make this a common practice from now on. This is my first and only boat I have owned.

When you put a torque wrench on the transom bolts, do NOT let the bolt spin at all. If you let that bolt spin, you’ll break your waterproof seal, assuming it’s still waterproof anyways.