F150 lower unit noise in idle

[bmurphy25]

Hi all,
New here and new to outboards in general. I've always had sterndrives. I have a new aqua patio tritoon with a 2013 f150 with less than 30 minutes on the hour meter. Was getting it loaded and ready to take to the lake this weekend and started it for the first time. Ran smooth when moving thru the RPM ranges without engaging the prop. When i engaged the prop at idle there is a rythmic knock that happens in both forward and reverse. If I move the throttle above idle the noise goes away. When the boat is in nuetral and i turn the prop by hand no noise. Any thoughts are welcome. If its an easy adjustment i'd rather just do it myself then haul it to the dealer and have to wait three weeks to get it back. Appraciate the help!

[TownsendsFJR1300]

Read posts #3 and #5 specifically :

http://www.yamahaoutboardparts.com/f...k-th22482.html

.

[RayBersch]

Read posts #3 and #5 specifically :

http://www.yamahaoutboardparts.com/f...k-th22482.html

.

Which is to say if it ain't broke, don't fix it - at least not at this stage, the motor is brand new. I am going to assume that all testing was done in the water although one could imply from your post that it was not, in which case I will also assume that you had supplied water to the engine via muffs on the lower unit not the flush hose. Don't play with the prop or the rpm out of the water, ain't good for nothin, and don't run up the rpm in neutral - doesn't even make nice motor sounds with this motor. Do break in the motor according to Yamaha specs - its easy, especially in a toon - go ride the lake for two hours or so to get the most important break-in behind you then go enjoy the boat. The other 8 hours of break-in pretty much mirrors normal use.

Good luck.

Ray

[Bilge Rat]

Common noise on that motor with SS props.

[bmurphy25]

Ray, Scott, rat,
Thanks for the quick response. Talked to the dealer and they explained the same issue is common with ss props. Seems odd as the prop is a yamaha reliance. They told me that if I can't live with it they would swap with a turbo prop. FYI. Yes I had it hooked up to muffs and was just moving thru the gears to ensure they engaged before I dunked it in the water for the first time. Love the site and again thank you for the help!
Brian

[TownsendsFJR1300]

I have a NON Yamaha SS prop on my 06 F150 but have never had the sound mentioned. I have replaced the water pump several times over the years.

Last time was done by a Yamaha Master Tech as it needed at least one seal (under the SS flat impeller plate-drive shaft) replaced (they did both seals((back to back seals))and pressure checked it)

I do flush the engine running on the muffs out of the water and at the power head hose hook up, NOT running. Never had a noise doing either.

I could stick it in gear on the muffs out of water, nice and quiet. Maybe I got lucky

[madharchod]

you have to understand this SS props weigh about 5.5kg and its about 5times heavier than the aluminum prop so if it is making noise run it till your gear box gives up and take it to the dealer for warranty repair lately a lot of gear box related issue have been coming up with Yamaha since they started using nearly the same seals in nearly most of their gearboxes
cheers