Securing a 150hp on 1974 Viper

[CJEhlers]

Just curious if anyone had imput on reinforcing a XR6 on a 1974 transom. The stern and transom of this boat are very secure and tight, however the 2000 Mercury is 400 lbs, almost twice as much as the original 115hp inline 6 that came with the boat. SO, I was going to use some wood and aluminum sheeting. Any input? I'd certainly appreciate it.
Thanks.
Chris

 

[redfury]

Re: Securing a 150hp on 1974 Viper

What is the HP rating on the boat? If you are putting too much HP on the boat, no amount of aluminum sheeting is going to help you, especially in the weight dept. That boat is going to be too heavy in the rear if it wasn't ever designed for that kind of a motor.

If you were to manage that motor, at the very least I'd want to add proper knee bracing from the transom to the stringers to handle the power, otherwise you might just find your new motor dangling from the boat like a very expensive anchor ( if you are that lucky )

 

[Chinewalker]

Re: Securing a 150hp on 1974 Viper

I capable hands, the Vipers actually respond well to lots of horsepower. That said, if the transom is original, I think I would consider a complete transom rebuild first, regardless of it's present condition, if you're going to put that much motor on there. Add a knee, or three, add thickness, add gussets, etc. to really tie it into the hull better. I've seen a few Streams with transoms torn out, not because of failed core material, but because there was enough flex that it tore the glass...
- Scott