Squeeling noise after installing new prop

[mrmamiller]

I switched from a Yamaha 13 x 19p SS 3 blade prop to a 13 x 15 aluminum 4 blade solas prop. When throttling back quickly, I hear a squealing noise, never had this before. Boat is a 17' CC with a Yamaha 90HP 2 stroke. Package weighs about 1900#. I dropped to 15 pitch because of two reasons, a) needed better hole shot and b) was over propped to start with. No squealing if I throttle back slowly. Hope I'm not doing damage. Any ideas?

 

[jestor68]

Re: Squeeling noise after installing new prop

Where is the squealing sound coming from?

Any time you order a Solas prop, you should order the Solas thrust washer to go with it.

If you order a Rubex, you get the thrust washer as part of the hub kit.

Did you tighten the prop nut to the torque pecs called for in your owner manual(25 lb ft)?

 

[mrmamiller]

Re: Squeeling noise after installing new prop

Jestor, I sent a message to Solas through their website inquiring as to whether I needed THEIR thrust washer, never got a reply. So, most of what I read on the forums indicated that my Yamaha thrust washer was OK, which is what I used.

On the torque, I tightened to make sure everything was well seated, then backed off for the castle nut. Never checked torque, but I can. The prop nut was probably tightened as much as on my previous Yamaha prop.

 

[mrmamiller]

Re: Squeeling noise after installing new prop

Update: Have been in contact with Solas. Torque to factory spec did nothing to improve symptomatic noise. Solas is covering prop under warranty, reason...."harmonic balance noise".

 

[Texasmark]

Re: Squeeling noise after installing new prop

My Merc prop torque is 55 ft-lbs for 90 hp.....good and tight. For reference, one could torque to say 65 and back off to say 55 to get the pin in the Castle nut I would think.

Squealing could be one of 2 things in my mind.

1. the prop contacts the gearcase or is loose on the shaft.

2. The overrun clutch, I guess Yammie has one like Merc does, is rattling on you. The overrun clutch presence can be checked in F gear, engine off, if the prop doesn't turn in one direction (ccw on mine) but ratchets and clicks in the other while being turned. This "overrun" function allows the prop rpms to overrun the engine rpms and continue to spin in the water decelerating at the rate of the boat speed reduction. When you decelerate rapidly, there is a large differential between the two rpms and you could hear the noise. It doesn't hurt anything but it can be annoying. Different prop characteristics affect the audibility of the function. If it weren't for this function and the prop was locked to the crankshaft, when you cut the throttle, the prop rpms would follow the engine and you would wind up with your teeth in your windshield if you have one.

Hth,
Mark