Prather Piranah???

[Colin]

Is anyone familiar with the Prather Piranah outrigger? I was just wondering how it performs. I started building one about 10 years ago and lost interest in it. It's been in my closet for a long time, but now it's finally almost finished. I'm very excited, but also very nervous that it won't run right. It's my first boat project.

Also, any advice for a first timer on operating or tuning?

Any help would be great!

Thanks,

Colin Hayden

 

[MikeP]

Colin,

I have one, I ran an OS 46 VRM in it. I think you will be just fine. What motor is in yours? The only thing to watch is all the screws that hold the motor mount and sponsons on need to be checked after every run they tend to work loose. If you run a 45 motor you need to keep it up on speed in the corners or the inside front sponson will dig in. Nothing serious but they corner better the faster you go, it's a pretty heavy boat. Runs really well in choppy water.

Keep us up to date, as always pictures are great.

-MikeP

 

[Colin]

Mike,

Thanks for the reply. The engine I have in it is an O.S.61 MAX marine engine. I'm hoping to finally test drive it for the first time tomorrow. What kind of fuel do you run? Tower Hobbies said the highest nitro they had was 30%. I bought the Trinity 30%.

Do you think this boat will go over 50-60mph. I'm so excited and just don't know what to expect.

As for pictures, I don't have any yet. I painted it with the Lustrekote paint( metalic plum) It looks good, but I need to get some stickers.

I still need to balance my prop. That should be a bunch of fun to, I've never balanced a prop before either.

Hopefully everything will go well!

Colin

 

[MikeP]

Colin,

Make sure your fuel has 18-20% oil content. I am not sure how fast you will be going. I think at least 40 and faster as you start tuning. If your motor is new you need to get some running time on it. You should start with a prop that is on the smaller side of what is recomended for the boat/motor. See how things go and adjust as needed.

Do a radio check for distance with the Tx antenna down and a water leak check on the radio box.

Mike

 

[Colin]

Mike,

My first test run went horrible! Remember I'm new at this. I started the engine backwards. When I put it in the water it started to go in reverse. Atleast it floats.

Next I started it I think in the right direction, but every time I went to give it gas it would stall. If I would give it gas really slow and slowly climb in rpm's until it was about half way it was fine.

Last, but certainly not least, my throttle servo has a twitch. I won't even touch the gas and all of a sudden it will floor. I have no idea why it's doing this. The radio is a brand new Airtronics. The batteries were fully charged. And all of this was in the pouring down rain to top things off.

Back to the drawing board!!

Any suggestions would be great.

Colin

 

[MikeP]

Colin,

Sorry to hear your first time out went horrible, But I am not to supprised. To me R/C boating is a fun challenge. If it wasn't I would of got bored and quilt.

Don't give up, soon a bad day will be when you could only get it to go 50 and not 65.

Here are some ideas on your radio problems.

Is it just the throttle and not the rudder that glitches?

Swap servo wires in the reciever see if the rudder does it

Does it happen just with the motor running?

I usually launch my hydros 2/3 throttle and a slight toss to get it moving on top of the water.

MikeP

 

[Colin]

It's definately a challenge! It keeps me coming back.

I'm not sure if it's only the throttle, or throttle and steering both. I had it running on my boat stand, and the only thing I noticed was the throttle because that was the very noticable one. It does only do it when the engine is running though. If I turn on just the radio and servos it's fine.

Thanks so much for the help and tips so far.

Colin

 

[MikeP]

Colin,

Be carefull when running the boat with a malfunctioning throttle servo. Better disconnect it and secure the carb lever so you don't over rev it. If both servos are glitching check the crystall, wiggle and tap on things, make sure your reciever antenna is fully extended. Look for two pieces of metal vibrating against each other. Try moving the reciever around in the radio box.

-Mike

 

[Colin]

Mike,

I think I found the problem! Since it only does it when the engine is running, it must be a signal coming from that. My boat has no exhaust throttle, so I have a pushrod running all the way up front to the carb for the throttle. After looking at it I noticed that my pushrod is rubbing on my engine in certain possitions. I'm going to fix it and hopefully fix my problem!

Does this theory make sense? I hope it works.

I'll let you know.

Colin

 

[Mark Sholund]

Colin,

Just wrap the linkage with a piece of fuel tubing.It cannot

rub against the engine that way.Just pull a piece of small

tubing over the push rod.That was your problem I think.

Also make sure your receiver antenae is isolated also.I

cut small pieces of tubing and thread them on the wire.

That should help you out.Make sure you are rich on the

carb also,new boaters usually run too LEAN.

See Ya,

Mark Sholund