Drilling Holes in Old Prop

[Gearyg]

I want to ask to see if anyone would have any comments on what I am about to do/try. I have a 210 with a Yamaha 115 4-Stroke. Every once in a while (once a year), I have an itch to go to a lake called Irvine Lake. The only problem is that the lowest speed I can achieve is 2.5~2.7mph and I need to get down to max 1.9mph or below.

I have an old prop, kind of nicked on the ends, wrong size for max speed etc...and I was thinking of drilling holes -or- cutting down the ends to slow my boat down (note that the max speed on the lake in 5mph so I would not need the speed or power)

My only concern is how many and how large of holes should I drill? Or how much should I shave off the end of the prop? Which would be the better option? Would this have any damaging effects on my engine, ie not enough torq etc...?

I know I can always use drift bags to slow down, but they are alot of hassel it seems like...plus I alredy have the prop and would have to buy drift bag(s)

Has anyone else tried this? Thanks for any input or comments.

 

[NCangler]

I would be very hesitant to drill holes in my prop. I assume that it could affect engine performance but it would also compromise the strength of the prop. Drift bags are the more elegant way to do this but you could take a 5 gallon bucket and rig it with a rope, toss it off the side of the boat to create some drag to slow down the speed of the boat. Don't put them off the transom as they will get in the way of your trolling lines. One on each side should keep the boat from listing to one side or the other. You may want to cut some holes in the bottom of the buckets to allow water to go thru them but so that they can still slow the boat down by creating some drag. The standard metal handles will probably not "handle" the stress of the drag so you'll probably need to rig the ropes directly to the buckets.

 

[NCangler]

BTW I did a quick search and found some interesting info related to slowing down the trolling speed.

Slow, Slow, Slow Your Boat

propeller pitch and trolling speed - iboats Boating Forums

 

[Gearyg]

Very cool information, thank you NCangler

 

[Push&Pull]

You can get a device called a trolling plate, that attaches to the cavitation plate and flips down to block most of the trust from the prop, slowing the boat considerably. Then flip up for normal operation. Should do the trick.