Bracket Failure at WOT

[sludgeguy68]

Still trying to figure out the cause (I'm still new to boating). This is the first season I was able to take out my boat - 1978 inline 1400 on a CMC jack plate - the thumbscrews for the transom clamp don't match up with the jack plate nicely (they wind up resting on the tops of CMC bolts), so the PO placed blocks of wood in there, I guess for a better grip. Now I kick myself for not looking into that weirdness over the winter.

I suppose I hit something on the water (no one really felt a jolt or anything), the boat just felt weird. I checked gear shifting and went slow, everything seemed normal. I think this is when the wood blocks may have gotten knocked out. I eventually opened it up to go back home and it was pretty choppy out, hit a bunch of waves, no problems all sounded/felt fine. Then the motor suddenly tilts 45 degrees sideways at WOT and almost dumps us in the water. I'm really glad the boat didn't go under and the motor hung on.

The trim brackets snapped at the jack plate, and the transom clamps broke at the thin bottom piece where it also bolts into the jack plate. Also have a chunk of metal missing from the the LU fin (where it separates when you drop it to change impeller), and the lower cowl disappeared.

I suppose once the wood blocks were gone, there was this 2" gap behind the clamps, and that didn't properly support the motor from stress.

Looking for any advice on repairing this and inspecting for other broken parts (tilt tube?) The trim brackets don't look too difficult to replace but it seems like the powerhead will need to be pulled to replace the clamp brackets. Also going to try to inspect for damage to the transom once I can get it out of the water.

Thanks in advance

 

[GA_Boater]

Re: Bracket Failure at WOT

I don't know about a CMC jack plate, but their tilt n trim bracket has an optional piece for clamp on motors.

The cause was incorrect PO installation and subsequent operation by you. You're new to boating, you will learn. Mostly through your wallet. I'm guessing the motor is hanging by the TnT hoses, get her out of the water as soon as you can before anymore damage occurs. Like the hoses giving up and the motor going in the drink.

I don't think you need to pull the powerhead to R/R the clamp and swivel bracket, but you will have to lift the motor. Post more pics of the damage and some not so close-ups.

Sorry this happened to you.

 

[Faztbullet]

Re: Bracket Failure at WOT

Those are the trim shock brackets and can easily be replaced, the original PO did not install bolts thru clamp bracket into CMC plate.If you look at bracket you will see mounting holes below thumb screws and end of bracket...

 

[Chris1956]

Re: Bracket Failure at WOT

That motor should be mounted with six 3/8" bolts. Four are to hold the trim brackets on and two thru the transom clamp bottom. The thumbscrews are unnecessary.

BTW - you must have hit something very solid. I had the same motor and hit a rock at 30MPH. The motor popped up and then went back down. It cracked off most of the skeg, but did no damage to the transom brackets or PTT brackets. I also hit a sumerged telephone pole w/o damage, at 45MPH.