Advice please - boat started shaking while driving

[Kight & Christine]

Took our R20 out yesterday and once we got to about 5 mph the boat started to shake really rapidly, almost like it was shivering or chattering. As soon as we got above 10mph it stopped and drove normally. We had it summerized a few weeks ago and have taken it out probably 4-5 times prior to this weekend with no issues. We haven't hit or damaged the prop at all and it looks completely normal. Any ideas on why this just started happening?

Thanks in advance for any advice!

[dingleberry]

Did it act this way repeatedly yesterday, or just once?

[Tault145]

Did it sound like the engine was running rough?

[houstonshark]

Maybe something got tangled in the prop and it cleared up when you went a little faster?

[rensink]

I'd check the prop just double check it's tight and for summarization did you do it yourself or a dealer?

[Kight & Christine]

It happened probably 90% of the time yesterday. The engine sounded completely normal, and we didn't feel or hear anything else abnormal.

We had it summerized at the Nautique dealer. We'll check if the prop is tight in the next day or so - we inspected it but didn't actually check if it was tight so maybe that's it.

[rensink]

It happened probably 90% of the time yesterday. The engine sounded completely normal, and we didn't feel or hear anything else abnormal.

We had it summerized at the Nautique dealer. We'll check if the prop is tight in the next day or so - we inspected it but didn't actually check if it was tight so maybe that's it.

Yeah it could be something simple as that, or it could be that the key in the prop slid over the winter or something moved just enough for it to start making vibration.

[tnvolgrad]

I had a similar experience last year - the issue was that I got a stick lodged in the first tracking fin. When I went above 5mph the boat started to shake pretty bad and slip like the transmission was going to fall out. It freaked me out and when I pulled it out of the water low and behold there was a large stick that got stuck.

I know it is a bit different from what you are decribing, but my dealer gave me some good advise. If you put the boat on the trailer/in the water and give it some throttle (clearly don't ram into the bow stop) you can try and immulate the vibration. I was shocked that a little stick caused that much impact on the boat and was reluctant to put in back in the water after the incident.

Agree that something may be lodged in the prop or was stuck/got unlodged while you were out. Hopefully that helps and nothing serious has gone wrong.

[Nobody]

Maybe something got tangled in the prop and it cleared up when you went a little faster?

Nobody got tangled in the prop and my sinuses are cleared up now.

[rensink]

The other thing is like seaweed or weeds if getting into shallow water. When this happened to me I just reversed fairly quick and fast to get it off.

[brett22i]

Im assuming you have the PCM engine in that boat. On my Marine power engines I will/have noticed a harmonic bounce/vibration at @ 1800 rpm. This is all very standard as this is when all of the moving parts sync together and create a slight vibration.

[Bruizza]

Have you checked the flux capacitor?

[91Terminator]

Have you checked the flux capacitor?

lol

[brett22i]

Good idea guys... it might not be running the proper 1.21 gigawatts

[What she said]

Check prop, shaft, and nut one more time.