Viper Re-Power

[deathmachine]

TWO QUESTIONS:

I bought my first Hydrostream! WOOOO HOOOO
1977 Viper - everything I've read is that all Hydrostreams have rotting floors and transoms. Mine feels totally solid.
Q: IS THIS POSSIBLE?

It came with a Merc 115. I went through the carbs and put in a new water pump just because.
Second time out - the top cylinder cooked anyway. BOOOOOOOOOOOOO!
I'm going to repower with another Merc inline 6 and have a shop do the tune up this time. Several are available on CL locally.
Q: 115 or 150? Would the Viper/150 be a "Death Machine" without solid motor mounts, dual steering, jack plate, etc?

My wife already calls it the "DM" (see login name - I would put the 115 shroud on the 150) and I would never pin it with her in the boat - I promise!

[VultureNo2]

Welcome to the Forum Congrats on the Viper. Unless the person you got it from said that the CORE has been replaced. I would be very careful with the speed. Sometimes solid floors are put in and hide the fact that the core needs to be redone. The cores in Vipers are made of Balsa which has many good things about it like light weight and extremely solid when glassed together properly. The problem is that almost every stream sold used today has seen many years of use and 99.9% of them have had water touch the balsa core at one time or another. That could be as simple as someone screwing a seat in and slowly over time, the balsa gets wet. The downside of balsa is that when it gets wet, it turned to chalk and looses it's structural integrity. Without that support, while you are tooling along and all seems good, the bottom can delaminate back and cause the boat to possibly hook sink. Not a good day on the lake. I like your thoughts about an inline 150 merc. That is what a lot of the original Vipers were rigged with. They look real sharp and get the kind of performance that you want. To check the core is the hard part if the floor is solid. You would be best to cut back a piece of the floor in the back middle and then drill some small holes into the core and take some samples to check. Also, you want to check the transom by removing some of the engine bolts and poke in there with a screwdriver or something and see if that is rotted. I like your excitement, but do not risk safety. Take the time to make sure the boat is solid. Even if you have to wait a year, like me, it will be worth every minute you put into it, and you will have the piece of mind of knowing that DM is only the name of the boat. Sorry for the long winded answer. Post some picture and don't hesitate to ask lots of questions. Bill

[hydrostream76]

congrats on your purchase, mine's a '77 too
it's a light boat ....
i had a 150 XP Evinrude on mine ...
i'm going with a 200 merc next

[deathmachine]

Thanks VultureNo2, I don't mind wind. Pics next week

The boat looks untouched inside, but I'll have to dig & poke more intensely. I've heard of taking core drillings and thought about it to be know for sure what I've got.

Obviously your vote, hydrostream76, is: "Too much is never enough"!!!!

Am I wrong that the Viper was "rated" for 115 hp max?

[77viper]

The good thing about the older boats are the rating was only a coats guard recommendation. I have talked to the local sheriffs and MN DRN and they both said as long as it was built before 1984 overpowering was ok.

I'm also going to be running a '77 viper with a 200 and a little happy gas, this will be used mainly for racing but I'm sure it will get some lake use.

Once you get up past 65 solid mounts and dual steering will help control the chine walk, a low water pick up with raised engine height will also help a lot.

Welcome to the forum and check your core.

[Surface Scratcher]

TWO QUESTIONS:


I'm going to repower with another Merc inline 6 and have a shop do the tune up this time. Several are available on CL locally.
Q: 115 or 150? Would the Viper/150 be a "Death Machine" without solid motor mounts, dual steering, jack plate, etc?

About 1982 outboards changed the rating system from rating hp at the crankshaft to rating it at the prop. The transfer of power from the power head to the prop shaft is about 10% (seems like a lot,but...). So a newer 115 is simular to an older 150. Anyway, your Viper will handle a 150 inline just fine because that motor is the optimum weight for that boat.

BTW, since your gonna at least be re rigging, consider getting the solid mounts in there. Those along with a safe steering system, foot throttle, and kill switch will keep it from being a DT.

Welcome

[buddhaboy]

I have a 150 on my viper and its not a toy!! Me personally, think a 150 is the perfect motor for a viper. there will not be much you wont be able to . goodluck this is a 25 inch with jackplate , boat does about 70 but with some small changes should see a little more speed

[deathmachine]

Thanks to all.

I've decided to:

Check my core, and if good,
pick up a 150 (4 for sale in Twin Cities this week)
install solid mounts and add other handling/safety mods asap

I'm excited!

[77viper]

Sounds good, where are you from?

[deathmachine]

Live in Bloomington, MN

I run it on Lake Washburn, Outing, MN