I got my build finished and finally got around to checking the CG. I used my GP CG Machine, and set it at 5 7/8". Balanced the plane on it, and the tailwheel is on the ground. Very tail heavy. I took a whole package of those GP stick on weights (still in the package) totalling six ounces, and with them sitting all the way forward on the prop the plane still hangs somewhat tail down (but with the tailwheel off the ground).

If it was nose heavy I'd know what to do, but it looks like it is gonna take 8-10oz way far forward to balance it. I wonder if maybe using longer standoffs for the engine might help?

Put a bigger engine on it!!

That's an O.S. GT33 with about 3.9HP. Probably enough engine.

Dead weight or usable (hp) weight your choice I'd use a 50cc and throttle control

Thanks. What if we pretend for a moment that I will continue using the GT33. Any helpful ideas about how to move weight forward to cure the tail heaviness? I am thinking some 5" Dubro inflatables and longer standoffs, maybe a spinner weight.

Originally Posted by Xpress..

Put a bigger engine on it!!

+1 ! :>)


Where are your batteries located ?

I attached a lot of weight to the back of the hatch under the nose. I have a DLE 35 and it flies great. It does 112 mph on a level pass.

Originally Posted by btomlinson

+1 ! :>)


Where are your batteries located ?

I only have one small one (LiFe 1800mAh, only weighs 4 ounces) and it is sitting under the wing, right about at the CG. I am thinking since 6 ounces added clear out on the spinner doesn't fix it, there is not much I can do by moving that light battery forward a few inches.

Funny thing is, I had bought the GT33 already for another project (GP Citabria) that I decided to not go ahead with, and I bought this plane to have a place to use it. It's rated for up to 35cc gas, and this is 33cc. Seemed like it would be a good match.

Right now the standoff setup has the back of the engine about as far back as it can be and still have that Pitts muffler clear the firewall (about 1/8" clearance). I am currently using about 1 3/4" of standoffs. I have some DLE 35 standoffs that are 2 7/8". It looks silly with those (but heck, it's a Stik, they always look silly!), but moving that engine farther forward might be just the ticket and it would not involve adding dead weight. I would just have to extend the throttle pushrod.

Oh, the ignition module is inside the front compartment. It is supposed to be at least 100mm away from the engine, so I don't want to try moving it forward. It doesn't weigh much anyway.

Space the engine out 1/2". That is the heaviest object, and you are not adding dead weight.

Originally Posted by Bunky F. Knuckle

Space the engine out 1/2". That is the heaviest object, and you are not adding dead weight.

That makes sense to me, thanks.

I have 2 giant stiks one with a bme 44 one with a bme 50 I have the fuel tank on the cg I spaced the engine out till the plane balanced.

Well they have lots of wing area. Adding some extra weight to the front won't really hurt anything. I needed to add lead weight to the front of my big ugly stick type of plane too. But as mentioned, you can go with longer standoffs for the engine or a larger and more heavy engine.

Years ago the engines had flywheel magnetos on them and weighed a lot more. I suspect that when the plane was designed, they planned for the heavier engines with the flywheel magnetos on them. But the design was not upgraded since then. That particular plane design has been around for quite a while too. Heck the manual for the plane shows them using a Fuji 32cc gas engine that has a heavy flywheel magneto on it too. It probably balances just right with the Fuji engine on it. But in thinking about it, I wonder what happens if you used a big glow engine, as the glow engine weighs a lot less than the Fuji 32cc engine does. I could see them putting a lot of extra lead weight on the plane to get it to balance.

Yeah, I noticed how dated the manual is when I looked up that Fuji engine. It has not been available for several years. Couldn't hurt to update the plane and the manual for what is available these days, but you know they won't do it.

Use longer standoffs. First use ply discs to establish how far forward the engine needs to be. Then buy longer standoffs once

Originally Posted by michaelnel

I only have one small one (LiFe 1800mAh, only weighs 4 ounces) and it is sitting under the wing, right about at the CG. I am thinking since 6 ounces added clear out on the spinner doesn't fix it, there is not much I can do by moving that light battery forward a few inches.

Funny thing is, I had bought the GT33 already for another project (GP Citabria) that I decided to not go ahead with, and I bought this plane to have a place to use it. It's rated for up to 35cc gas, and this is 33cc. Seemed like it would be a good match.

Right now the standoff setup has the back of the engine about as far back as it can be and still have that Pitts muffler clear the firewall (about 1/8" clearance). I am currently using about 1 3/4" of standoffs. I have some DLE 35 standoffs that are 2 7/8". It looks silly with those (but heck, it's a Stik, they always look silly!), but moving that engine farther forward might be just the ticket and it would not involve adding dead weight. I would just have to extend the throttle pushrod.

Oh, the ignition module is inside the front compartment. It is supposed to be at least 100mm away from the engine, so I don't want to try moving it forward. It doesn't weigh much anyway.

IMHO every ounce counts
I would move the engine out 1/2" and the battery if needed
Sounds like your close to having this resolved !

I have the same plane . When I get to it I will use a DA 50 or 35

Have fun !!

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