Whats the lowest powered STV that you have ever seen?

**JPEROG** · 05-13-2019, 09:55 PM

As the title says, I picked up an STV Pro Comp for my son as his next step in boating. I am going to rig it with the same 15" 115 optimax that he had on his 15' wahoo. Any idea what it should run with 2.33 and a 5750 limiter I know it won't be too crazy. His wahoo ran a best of 60 and my first pro comp with a carbed 200 ran 94 at 7K with a 1.87 turning a 30 chopper worked by Tillman (30 years ago).

Joe

**99fxst99** · 05-13-2019, 10:07 PM

I will guess about the same. My concern would be that the 115 wont make enough power to get enough air under the boat to overcome the drag of the hull and sponsons being fully immersed.
I am thinking of a good first boat for my 12 yr old. He is already a capable operator, and we are working on his boater's license at this time.
I wish I still had my 18 Talon to put a smaller motor on for a first performance boat. Keep us informed on how this project goes.

**JPEROG** · 05-13-2019, 10:11 PM

The good news is that he only weighs about 100 lbs so we will see. I have to clean up the rigging and make some changes before we hang the motor. It will be a couple weeks before its wet.

Joe

**kellytheaker** · 05-14-2019, 06:17 AM

Joe sounds like an exciting project for a father/son . I have seen your rigging sooo it will be interesting to see the finished hull with your input. I would suspect an improvement in speed . I think you will have a pretty trick tunnel seeking out 75 but looking like 90 . Have fun - whenever I hear of these projects supposedly for the kids - I always look at the parent and you realize it' for both of them in reallity . Those hulls are super neat just sitting still .

**JPEROG** · 05-14-2019, 07:02 AM

Well, its truly for him but it wouldn't happen if I wasn't here for sure. Don't get me wrong, I love seeing young guys get involved in our hobby and watching my son expand his experiences-its just much harder for them then it was in the 80s when I did it. I remember going into my credit union at 16 "with my dad" and getting a loan for a new motorcycle in less then 15 minutes-those days are history for young guys and if they have the cash then its the liability cost that stops them next. I am having a hard time insuring this pro comp with a baby motor as a fifty year old adult, yet when I was 18 they insured me on my first STV with no issue (there is some truth to "the good old days").

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Joe

**Euroski** · 05-14-2019, 07:22 AM

Average Euro with 200 may break 90. But have no idea with 115.

**David - WI** · 05-14-2019, 08:26 AM

If you just plonk a 100# driver and 115 Opti on a 19' Euro that was already entered into the Tunnelboat simulator, you get 63 mph top speed... for what it's worth.

**Capt.Insane-o** · 05-14-2019, 08:42 AM

Gear ratio is the killer. The 115 and 125 2s had a 2.07 might be worth looking into a swap later

**PaulR** · 05-14-2019, 08:51 AM

My nephew had a Euro with a mid 1980's 150 Merc on it. It ran 70-75 but that's right where it wanted to pack air so it hopped on the top end unless you headed into a stiff wind on some chop. My Drag motor is down right now so I think I'll put my 135 2L powerhead on my rocket and see if I can get 60 out of it! LOL!

**JPEROG** · 05-14-2019, 09:21 AM

I have a 200 waiting but I need to restrain myself and make him learn the characteristics of crossing wakes and stepping over them when he comes up on someone to pass ect. I told his mom that the 115 would stay on it for a year.

Capt.Insane-o

Spring!

Gear ratio is the killer. The 115 and 125 2s had a 2.07 might be worth looking into a swap later
--
We have a set going in it now.

Joe

**JPEROG** · 05-14-2019, 09:26 AM

Originally Posted by David - WI

If you just plonk a 100# driver and 115 Opti on a 19' Euro that was already entered into the Tunnelboat simulator, you get 63 mph top speed... for what it's worth.

My original guess was 65 which will be perfect. I think that a big ear chopper or an ET is going to give him the ability to trim it up and learn at a reasonable speed.

Joe

**mach351** · 05-14-2019, 11:47 AM

I ran an Xr6 150 for years on my STV. Best speed was 110, but it would run upper 90’s everytime it went out. We also rigged a mirage ski racer with a 2.0 150 and it went 96. Never messed with anything smaller than a V6, but I agree rpm is going to be your issue. Gunna need a bunch of pitch.

**XstreamVking** · 05-14-2019, 12:04 PM

Wasn't there a vid of an stv with a 150 4s honda on the web? A 115 opti with a small blade 24p trophy should go at least 60.

**JBS** · 05-14-2019, 05:23 PM

I'm thinking 60s too?

**home made tunnel** · 05-14-2019, 05:40 PM

Originally Posted by XstreamVking

Wasn't there a vid of an stv with a 150 4s honda on the web? A 115 opti with a small blade 24p trophy should go at least 60.

Yes there was, but that guy with the Honda had a crappy prop, and I think it topped out at like 30mph haha.

If your son does 65mph with that boat, that's great. I'm lucky to hit 65 in a headwind with chop with my little 500lb tunnel with a 115 Pro XS on it. 23p through hub cleaver, 2.07 gears. And mine's hopping on the top end.