I bought a used Northstar with a 51 on it. Will this be enough motor to fly off the water? Will this plane slow down or will need full throttle? what do I need to look for on the first flight? should I use the manu. suggestions on the throws?I am flying a seamaster now.thanks for the help, Rick

I have an old OS 46SX on mine and it's a rocket!

One thing to look for is: The elevator pushrod comes up through the rear of the engine nacell - make sure that it can't flex at that point, or when you try to pull out of a dive, the airflow can push the elevator back down which greatly reduces the elevator's effectivness.

If it doesn't have any support back there, you can just glue a few balsa braces back there with a hole for the pushrod - so it can still move back and forth, but can't flex

I also have a .46SX in mine, flys great. I also hace the elevator pushrod support...

Instead of bracing the nyrod inside the nacell I run a piece of solid 2-56 rod from the control horn down to where the outer nyrod exits the fin inside the nacell. You can then pull the elevator pushrod out if you ever need to service the fuel tank.
Peter

That works too. You can do any number of things - just keep it from flexing

Where can I purchase a new Northstar? Are they kits or ARF?

TF

The Northstar plan was published by RCM (issue 3-86) as plan #pl-960

You could build it from the plan, or a kit made by Balsa USA

When you build it, I too recommend improving the elevator linkage like the others said.
I would also strengthen the join between the engine pod and fin, by filling the corner with balsa triangle and covering with light glasscloth/epoxy from the pod sides right down to the fuselage under the wing.

Another useful mod is to install two aileron servos and connect them as elevons, using a Tx mixer (as well as the usual elevator).

Check out the link: Northstar Mods, tell me what you think. I built a tray type of deal that goes in the back end of the pod behind the gas tank. It holds the elevator and throttle servo that has very short push/pull rods to the control surface and engine. Works very solid. I also recommend two servos for the ailerons. Run them as standard ailerons or mix them as mentioned before. There's plenty of room up front for it and you'll need weight up there anyway, might as well make it usefull.