Prather Tunnel

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normlee

Well-Known Member
Joined
Feb 13, 2015
Messages
579
Does anyone have any setup tips for this old girl please? It has a K&B 7.5SS on the back. We got it to turn ok now with a fin installed. Seems to be very flighty in the front, where should the CG be?

Thanks guys.

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Typical CG on most model tunnel boats is 1/3 forward from the transom. Seems like I remember guys who ran that boat had 4 - 6 oz. of stick on lead at the sponson tips.

JD
 
Normlee i used to have the same tunnel years ago with a 7.5..

I cut a small opening on the tips of each sponson and poured 4oz of lead soup in each sponson total 8oz and it ran very well..(chopped lead and epoxy)

where did you find the hull kit?

David
 
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I just bought a used Prather II 27" going run it Brushless . I had a 7.5 K&B would like some conversions photo if possible. Also what Servo would I use . I have new 1/4 scale servos .

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my first boat was a lap cat 2 with a red head 7.5 , too much motor for the hull, was upside down more than anything. a stock 7.5 would have worked much better. my opinion this was a 40 mph boat, start to push it over 40 and that old hull design starts to get cranky. stuffed it so many times that it split the seams all the way back. bought a b/m leecraft and it was a different animal. I am not saying it wont work but you will master flushing water out of that motor every time you run
 
It was a great play boat first boat i owned a Lap Cat2 had a stock engine ran well for me just learning but didnt stay on the water all the time.
 
Have too mod bilge area , the lips the cowl sits have drill umpteen times . Reinforced with wood >> done poorly << now going get lightweight aluminum angles that will epoxied and squeeze riveted on to replace the lips >> squeeze riveting << is a aircraft process .
 
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My old mate Benny's Prather, he loves the old tunnel hulls and K&B engines. I scored this new 7.5 Pro in a deal and Benny was the best man for it. If you need a boat painted and/or blue printed here in AU I can pass on the details.
 
My old mate Benny's Prather, he loves the old tunnel hulls and K&B engines. I scored this new 7.5 Pro in a deal and Benny was the best man for it. If you need a boat painted and/or blue printed here in AU I can pass on the details.

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Getting down to plumbing now . On the K&B the water feed side for cooling , mine has a nipple and what looks like a small tube just below the ride plate . Would it be better to plumb in two new pick ups . One for ESC and one for motor ? and one more question should I inlarge the hole at the top of engine cover and lower the cowl . Thanks Paul
 
Is there a web page I could look at that shows how the motor cowl,is mounted that I could look at . I know I am not a regular poster just want to buy another if I don't like how it looks . Paul
 
What ever happened with this Prather ? My first nitro R/C boat was a Prather 36" ( I asked the hobby dealer for a 32" but he gave me the 36" , never realized it ) with a KB 7.5, the boat was fun with the orignal prop it would cavitate, you'd back off the throttle, then back in and the boat would leave the water, very very entertaining, had so many laughs with that, and yes flipped over a few times. After that a Prather S/S 230 and ran the heck out of it for years and years, she's a dust collector now but still looks good!
 

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