prop chatter when going into gear?

[Eye owa]

New prop, love it, but concerned about what it does when I shift into gear. It chatters like it is only halfway in gear. I can get that to stop after a couple of attempts but it shouldnt be doing that. I sometimes can hear the SS prop knock at idle but that is different from the chatter. What is going on or what do I need to change?? Maybe take up golf instead?
TIA for replies

[Ltrain]

If it's prop chatter and you're using a flo torque 2 hub you can go to a 3 or 4 to stop the chatter, that's what they were designed for.

[TomP.]

The early flo torgue hubs needed to be torqued to 100 ft lbs that would stop the chatter. Check tighteness

[KPKyllo]

I have a Merc 115 4S CT with a stainless prop and I had prop chatter until I installed a Flo-Torq IV hub kit.

[Eye owa]

Originally Posted by ltrain

If it's prop chatter and you're using a flo torque 2 hub you can go to a 3 or 4 to stop the chatter, that's what they were designed for.

Thanks for the advice. One thing that concerns me is that everything I have seen/read says the IV kit is for the 135-200HP Verado. Any problems or issues running it on my 90 HP 4 stroke? Affect warrranty?

Thanks, Terry

[Snowking]

They make the flo torq 3 for the smaller engines. https://www.quicksilver-products.com...-iii-hub-kits/

I think they should by torqued to 55 ft pounds. It has instructions in the kit. Little advice. Next time you post a motor question. You should say what motor right away. Same goes for boat questions.

[REW]

Eye,
I expect that you know the answer, but you have stated you hear prop chatter.

Are you sure that it is prop chatter, and not lower unit gear chatter from less than complete gear shifting when going into gear.

i.e.
If you put on a completely different prop that has been good for you in the past, do you hear any chatter of any kind at all?

[Eye owa]

Originally Posted by REW

Eye,

Are you sure that it is prop chatter, and not lower unit gear chatter from less than complete gear shifting when going into gear.

i.e.
If you put on a completely different prop that has been good for you in the past, do you hear any chatter of any kind at all?

Good thought! It sounds like the chatter from "old" motors when they weren't fully shifter into gear. If I shift in and out a couple of times, it usually goes away until next shift, either forward or reverse. Was there something I might have overlooked when installing the SS prop?
Thanx for the suggestions guys>

[KPKyllo]

It sure sounds like prop chatter to me, especially with it starting when going to the SS prop.

[staylor]

It does sound like “prop knock” which occurs often on 4 stroke outboards using SS props.....but....you should check your shift linkage first to make sure that the chatter going into gear is not being caused by an out of adjustment shift cable. This check can be done on the trailer with a helper or you can have the dealer check it if you don’t want to do the adjustment yourself.

If the shifter is set up correctly then you can turn your attention to the prop and install one of the cushioned hubs. On my 150 4S I had to readjust the shifter cable after about 20 hours use because the shift cable appeared to have stretched a bit. I also had significant prop knock with a SS Merc Tempest Plus prop. In my case I also had a Merc Trophy Plus SS Prop in my prop box which is smaller in diameter than the Tempest, lighter in weight, and on the 150 4S runs as an over and thru exhaust hub. All prop knock vanished with the Trophy Plus so I then picked up a Trophy Plus in the proper pitch for my rig.

If your 115 has the standard gearcase then your best option to fix prop knock is a cushioned Flo-Torque Hub kit. I don’t know of any prop mfg offering an over and thru hub for the 115 4S which limits you to the cushioned hub.
Doug