Boat is 6 years old now and my prop has a couple nicks in it. It’s stainless, I’ve been careful but have ran ground 2 or 3 times over the years. It has some nicks and dings but nothing serious. This year I noticed I’ve lost about 2 mph at top end, used to be able to hit 40 but now top out at 38. So question is at what point should I be considering fixing or replacing?
Boats & Motors
When to replace prop
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How are you measuring your speed? If it's not using GPS, you may have a restriction or crack in your water line or pitiot tube. A few minor nicks in your prop blades won't cost you 2 mph. Chunks missing, a rolled blade edge or bent blade might. But not a few idle speed nicks. Are you getting the same WOT RPMs?
If it is a stainless prop, it is worth having it reworked. If it is aluminum, keep it as an emergency spare and buy a new one. Most prop places charge $50-80 to repair an aluminum prop and you won't have it back for 4-6 weeks. My time on the water is worth a few extra dollars. We have a shorter boating season in Wisconsin than most states. I'm not going to miss a third of it waiting for prop nicks to be repaired. I have 5 props for my boat...some are for different applications, but 3 of them are the same 13x21 pitch props so if I hit something and tweak a blade, I have spares on hand to get back on the water immediately.
My 40 hp tiller has hit sand bars, muck, and logs while river fishing. The prop is aluminum i can tell in the feel vibration on the tiller handle when the prop gets dinged or bent and yes I lose 1-2 mph usually. I always buy a new one cause the prop make alot more vibration when it's damaged which can lead to more problems. Then I keep the least damaged prop for a backup.
Motor is 90 hp merc and 1675 Lund impact. Only 3 times I hit anything was at idle speed and “found” a gravel bar and immediately went into neutral and trimmed up. Don’t really think the speed loss is a motor issue, she still starts, idles and runs like when new, just feel the nicks on the prop aren’t making it as efficient as it was as new
That's a personal thing. My props are almost like new, but I always have a spare prop. I don't know your boat, so hard to say, but at 40hp tops, I would purchase a new or like new aluminum prop then have your SS rebuilt. Once done, put the SS back on and keep Aluminum as a hot spare. I buy my props used off Bass Boat Central or scream and fly. Both cater to bigger motors but props for smaller motors do come up. Lots of guys buy a prop, find it is not right, then sell it for 30-50% off new with no dings. As a side note, 2 mph loss could be an engine thing and not the prop unless you just hit something.
Displaying 1 to 8 of 8 posts
