Logo

Strange growl at certain bandwidth range

ezymeat

New member
I have a DF90A with about 70 hours work on it. Started gettimg a loud 'growl' from the motor at 3200rpm which disappears at around 4000rpm.

Doesn't happen all the time - for example I can run at this rpm band for 30 mins with no noise, then I stop in idle for 5 minutes and take off again and the noise comes in at 3200 and it'll stay until I hit around 4000.

Next day I can go all day without the noise.


Tried to replicate the noise on the trailer with the muffs on but can't. I played a recording to my Suzi dealer to prove I wasn't delusional. He certainly noticed it but he can't work out the cause.


Stainless prop is in as new condition and other than the growl there's no noticeable change in the behaviour of the motor. There may be a little bit more vibration, but it's hard to say.


Any thoughts would be most appreciated.
 
Last edited:
Back
Top