Blowout at around 69mph.

[skialot2]

My nose cone lower unit is junk. Carrier nut threads are stripped in the case. I went for a ride with a crappy lower unit that used to have a nosecone and has a big chip in its small skeg. I used a Bob's transom mounted water pickup. It is definitely faster than the nosecone lower by 4-5mph. But I think because of the chip in the skeg I had a major blowout. Boat made a really hard right. Nobody got hurt, but we did get a little wet.

[LakeFever]

Yikes

[sharpeye Mike]

I never had one this bad. Not even close.

[Aaronhl]

did you bump the trim up on the right blinker twice at :53 cuz it blew out right after that

[skialot2]

did you bump the trim up on the right blinker twice at :53 cuz it blew out right after that

Yup. looks like 1 bump up about 2 seconds before it blew out. But it wasn't trimmed very high. Transom was all the way up though. Propshaft level with the pad. Never had a blowout like this before. I always thought a blowout was that prop slip you get when you over trim. But that and this are two completely different things.

[donmac]

with the shaft that high, small skeg and no tamer, there's not much left in the water to keep the boat from crabbing and then not crabbing swapping ends. wonder where the CG is with with that much weight in the seats!

[DangerNewb]

Considering that skeg, all I can say is, "what did you think was gonna happen?".

[LakeFever]

Prop slip as you mention is cavitation. Fairly common with some props and set ups. Blow out? Well, now you know it’s a sobering experience to say the least. It’s a complete loss of grip from the prop and lower turning the hull into a skipping rock. I’ve had it when running perfectly straight and the hull just drops straight down just like you tripped down a step or something. Instant drop. Sometimes when it’s close to happening you will feel crab walk where the hull starts moving sideways instead of just forwards. When you have a good handle on how it all feels you can usually feel the prop/skeg getting a little rubbery just before it lets go. I had blow out and paddle wheeling a bunch of times on my first stream with a jack. I’m very sensitive to that rubbery feel now. Props too make a huge difference I don’t like those loose ones that push and don’t hold the hull. A good prop rides tight and holds with confidence. Anyways seems a good lesson here for anyone else who stumbles in this thread. Don’t run sub par props/lowers for high speed stuff.

Thanks for sharing this skialot2

[rock]

I had n STV with a modified 260 blow out at 117. Scared the crap out of me. Once I regained control of the boat I looked down at my trim gauge and seen it maxed out. Either it stuck or I hit the trim button inadvertently but either way I was lucky as hell it blew out before it blew over. Never had an issue with trim before this incident or after so I assume it was strictly driver error. It's easy to muck things up when you are approaching the boats limit and too much trim will definitely lead to a blow out condition.

Rock

[LakeFever]

Jacked to max speed height, trimmed to speed level can run straight just fine but turn too much and look out. Blowout happens easy this way

[skialot2]

I have been running all year with the nose cone lower unit jacked all the way up. Too much trim just caused unmanageable chine walk. No problem with cavitation except in the tightest of turns. Until now, I thought cavitation and blowout were the same thing. The sudden loss of grip of the prop along with the sudden change in steering torque and direction. Just didn't think I was going fast enough for it to matter.

[LakeFever]

I can relate to your shock of this event. I had no idea what was happening either it’s a very unique experience to the uninitiated. Probably didn’t have issues before because the hull was still wet enough to hold course, and the extra bullet length with the cone. It’s when your aired out good n proper things get wild. So, seems your hull reaches that zone around 70mph which is certainly humming along. There’s not a lot of boats out there that can run 70, that’s definitely fast boat only arena

[Jimboat]

I went for a ride with a crappy lower unit that used to have a nosecone and has a big chip in its small skeg. But I think because of the chip in the skeg I had a major blowout. Boat made a really hard right.

Your nosecone and skeg damage can certainly contribute to the speed where the onset of blowout occurs. Higher the speed, the more sensitive the 'trigger' of blowout can be. Note that 'cavitation' is not 'blowout'. Here's an article on Gearcase/Propeller Blowout. [more articles here: aeromarineresearch.com/performance_articles.html]

[skialot2]

I know there was a good bit of corrosion on the nose (all) of this gearcase. But I don't remember there being this big a divot. It seems to be bigger and now there is a shiny spot. Maybe I hit something? I did go out a few days before by myself. I went a little faster that day (1 MPH) and nothing happened. Boat drove great.

[AlliStan]

I hit a submerged log in the river Sept. '23 at around 65 mph in my '87 Allison XTB. Never saw it, sun low and in my eyes causing bad glare. She fortunately hooked left which kept me in the driver's seat but it was violent enough to throw me into the side of the boat and dislodge my foot from the Hotfoot. The hook killed the boat's speed significantly but it still hit a mass of tree roots on the SC bank with enough speed to break the 'glass on the front left side of the "nose" and destroyed the rubrail. My passenger was sitting behind and to the left of me and was thrown violently into the right side of the boat, hitting her head against the top edge hard enough that she awoke the next morning with a concussion. There was a small patch of blood on the boat near where she impacted it.

Absolutely no damage to the nose cone, skeg, or prop. I saw the log bobbing just after hitting the bank.

Hooks are nothing to take lightly.