jalers

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I just got a used 40" tunnel hull boat with a K&B 11cc outboard engine and the guy told me that it wants to fly. My question is what can I do to keep the boat from flipping and if the motor is to big? I have not driving it yet cause I want to clean it out and get some stuff done correctly on it. I also would like some ideas on the wtaer proof box or where I can go for some pictures to guide me. As you can see I'm new to R/C boats and can't wait. Thanks ahead.

wave waker

I think the hull size can handle the 11cc, just pay attention on the prop angle/height and CG,,as the prop position go higher the more lift same with prop angled up makes the bow lift tendency to blow over,,,,with cg the more back located the more chances os blowin over.

TIA

Yeah an 11cc is not going to overpower a 40" boat.

topfuel4430

Post a picture or two of what you have and we can give you a much better idea of what you need to do. The things stated above are a good guideline.

Most guys seal the radio box with "tape", but you may have an old design where they used to screw down the radio box lids.

~James

jalers

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Sounds like good ideas, I will have to look at the prop angle. Will post some pics later tonight. Yea the box is sealed with one screw and looks like it had tape and some kind of silicon. getting ready to make a clear cover and should I keep the screw and add one on the opposite side? Thanks

jalers

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The angle and CG looks kind of good , but I am not sure. Here is a few pics of it.

TIA

You might try mounting an adjustable motor mount and play with it a little bit. think I just saw one on ebay for $5

Little stick-up lead weights on the nose might help the plane as well.

wave waker

it's hard to tell the prop angle and height from the picture, if u can sit the boat on top of the table with the transom just on the edge of the table and let the engine hangin' that way we can see the prop angle in relation to the tip of the sponson...

btw, i just noticed the steering linkage looks thin for an 11 cc motor,,just for the safe side.

jalers

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I will try the lead weights and where is a good place to find the links for the steering or any other parts? Want to get it right before takeing it out, also where can i get a muffler for it? But here is a straight angle shot.

topfuel4430

The motor looks too deep, it may be just the angle from the picture, but? If you can set it on something FLAT, like your kitchen counter (make sure the wife/mother is not looking) and take a shot where the camera is level with the bottom of the boat. I would start out with the top of the prop shaft level with the bottom of the boat. You have to get it VERY close as a small adjustment can make a big difference. As previously stated, you should get an adjustable motor mount.

They dont make a "muffler" for the stock lower unit. The lower unit itself acts as a muffler. Those engine are VERY loud with the stock lower unit, you could always put a tuned pipe on it with an add on or built in muffler.

Now that i see the boat is a prether, there is no way the boat is 40 inches long. That may end up being too much motor for the boat. The stock K&B's make a fair amount of torque, and the Prathers have a tendancy to do weird things when up to speed.

As for your steering hardware concerns, www.towerhobbies.com has most of everything you could possibly need.

Hope this helps, James

jalers

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Helps out alot, I will try to get those pix later tonight.

jalers

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More pix on a table at different angles... hope this helps .

jalers

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The boat is 36" and with the boat it's 41"

wave waker

looks the engine set is low, maybe just the camera view angle.

btw, i got pics of my 7.5 showing the linkage n the prop/engine set-up,, i used 4-40 rod with carbon fiber tube, a ball bearing joint...the prop angle if u notice is negative, pointing down,,hope it helps in some way...

RK Racing

thats a prather lap cat 3 its a 36" tunnel its made for the 11cc try running the prop about an 1/8 below the transom with a little down


u need the adjustable motot mount that prather makes for that boat it let you adjust the pitch it not on your boat heres the part number no.5191 adjustable outboard motor mount [310]835-4764


if that boat is set up right it should run in the mid 50s to high 50s thats with a stock 11cc motor

jalers

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Thanks for telling me what it is, now I can research it a little better. Now I need to find an adjustable outboard motor mount. Can't wait. I really apreciate all this info and also wish I can find some local R/C boat action.

RK Racing

u can get the motor mount from prather it under 30 bucks there phone # is [310]835-4764