Strange Vibration or Shuddering...

[azwakeboarder]

Hey All,
I have a '06 SAN. I have a strange intermittent problem that only occurs occasionally. The boat will make a strange shuddering or vibration sometimes. This occurred once before at about 50 hours, I now have about 160 hours on it. I took it to the dealer, the first time and the only thing they found was that the strainer was full of debris. This time I had seven people on the boat going 23 with Perfect Pass on and the stock ballast system full. It was pretty blown out and we were traveling through some rollers too. The boat basically started to shudder or vibrate pretty bad so I cut the throttle and turned off the boat. I check the strainer since that was the supposed cause last time and it was clear. I drained the ballast and started again and everything was fine. I later dropped three people off at the dock and filled the ballast system back up and the problem didn’t re-appear. Has anyone had a similar occurrence? I don’t want the dealer to think I am nuts when I take it in. I checked all the fluids, even the v-drive, what a pain, and everything is fine. The boat has the little ACME 381 prop on it that needs to go, could this be the problem, possible cavitation? We were traveling in a straight line and I’m not sure if the boat slowed down before I cut the throttle. What is everyone else using for a prop? I generally have about 7 people in the boat with full stock ballast. Top speed is not a big issue.

Thanks,
AZwakeboader

[BP22]

Is the Perfect Pass engaged everytime this happens?

[azwakeboarder]

No, I don't believe so. It was engaged this last time though.

[Pratt]

You are getting a piece of small debris stuck around the propeller. We ride in a river and this will happen from time to time. I have been in more then one SAN that has had this problem. To correct the situation, stop and rather agressively blip the throttle in reverse. Obviously, do not slam it into reverse and rip the transmission out.

I do not have the technical reason for why this happens. It has typically been a piece of grass of small stick, and this would go along with your strainer being full. I hope that this helps.

[azwakeboarder]

So has everyone experianced this?

[bkhallpass]

I've definitely had the weed thing that Pratt described. BKH

[Andrew]

first thing i thought of was engine alignment, but with it being an intermittent problem i don't guess that the problem. can't say i've ever noticed vibration from weeds, but i'm sure that my boat vibrates a little more than urs anyway lol

[Quinner]

We have weeds on our lake from year to year in the spring, not only will you get vibration but you may also notice the motor strain a bit, on my 206 if you pick up a large amount of weeds the wheel will shake also. Reverse will clear the prop, I just bump it in normally and give it a small amount of throttle, a couple times if you are really clogged up. Running through weeds is more of a problem at slower speeds, if you pass through them at slalom or barefoot speeds it usually just cuts through them.

[azwakeboarder]

Any suggestions on what prop to upgrade to? I have heard the 1237 is good for wakeboarding...also the 835.