Maiden voyage is a fail, ideas?

[ourlee]

Hello,

Took my new AP 240 SL out for the first time yesterday [150 Yamy 4 stroke]. I have a vibration with the motor at 2200 rpms and also at 3000 rpms. My experienced boater friend and I replicated the problem 6 or 7 times. He thinks it may be trim related. It manifested itself the first time when I played with the trim for the first time. RPMs were around 2500 and jumped to 3300 and the vibration started. I'm breaking the motor in [now at 2.7 hours] varying rpms now maxing at 4000 rpms for the next hour or so. This did not happen during the test run at the dealer of course!

Debris is not the issue, propeller is clear.

Obviously I'm waiting for a call back from the dealer but I wanted to run it by you good folks too. Also, the dealer is 2.5 hours away. I have a local dealer but he did not have the boat I wanted in stock. He'll take over warranty but I want to make sure this isn't an initial set up problem before I hand it off to the local guy.

Thanks,

Rick

[lakerunner]

Trim position could be causing a harmonic vibration at certain RPM's. I have one at 900, not 800 or 1000. The only thing that it could be is that as computer showed motor was performing smoothly.

[jrolin1]

My boat will have a little extra vibration at certain trim setting around 2500 rpms. If I trim it down a touch all is smooth. At higher speeds it does not. Also the load of the boat seems to matter. If I am alone it does not do it at all.

[ourlee]

My service rep said basically the same thing guess i'm I little jumpy being a newby and all. Thx crew.
Rick

[bassn386]

I've got that harmonic vibration at 1000 rpm. I go down a hundred or up a hundred and it disappears. I guess it's the nature of the beast, but I don't remember experiencing this with my Optimax on my bass boat. Of course, I don't run at slow speed very often unless I'm pulling away from docks or the shoreline and then I'm up on plane and scooting to the next spot.

[playcat]

Every boat has a "critical speed" where everything sort of falls into place and sets up a vibration that can be felt. Even large ships have one or two engine speeds that cause a vibration that can damage bearings, gears, etc. We always avoided running at those speeds - just the nature of the beast, as noted previously.

[Red555]

When you have the 20 hour service done, they can read the codes in the motor's computer and tell if anything tripped a code warning.

My 20' with a Yamaha 90 has a low rpm (1600~) vibe, but it goes away at any other rpm.