Nik in prop...how big is too big?

[ccyoder]

1989 Glastron Sierra 195ss
4.3L Mercruiser 175 hp
Alpha One
14.5x19 3-blade aluminum

I boat in a relatively shallow lake. I hit a stump (I think) last weekend while idling through a no-wake zone. Boated over to a beach and checked the damage. I have what looks like two nickles missing from one of the blades and a dime size chunk off a second blade. No vibration or performaced loss to speak of, though I know that's not the green light to keep running it.

When I notice a prop has nicks, I just replace it as I don't want to risk damage to the engine or drive. This will be the second prop I've switched out this summer. Am I overreacting or is this the way to go? Are there any guidelines as to an "acceptable" amount of nicks in the propeller blades?

And no, boating in a deeper lake is not geographically feasible for me .

Thanks.

 

[Silvertip]

Re: Nik in prop...how big is too big?

Nickle and dime size pieces missing from a prop is an excellent reason to change the prop or get it repaired. Pieces that large can cause imbalance and other stresses and may even cause complete disintegration of the prop which is not a good thing when the pieces begin flying at a water skier, tuber, or wakeboarder. Are you trimming up when passing through shallow areas? If not you should be.

 

[ccyoder]

Re: Nik in prop...how big is too big?

I trim way up (above halfway) when coming off the open water into the no wake zones, which are the shallow areas.

So, to the broader question, is there a size threshold for these nicks e.g. 1/4 in diameter, or is any nick too much damage?

 

[Silvertip]

Re: Nik in prop...how big is too big?

I thought I answered that! But here it is again. A prop with a crack, nick, chunks missing, or any other damage has stresses that can cause the prop to disintegrate at high speed or under heavy load. Dime and nickel size pieces missing from a prop are sizeable and dangerous. Would you like to be water skiing behind a boat that threw a blade, or pieces of one at about 25 MPH?

 

[ccyoder]

Re: Nik in prop...how big is too big?

Any nick is too much damage. Gotcha. Thanks for help.

 

[hwkypuck]

Re: Nik in prop...how big is too big?

good stuff