Hey guys I'm almost finished building my gp arf stuka. But, the engine mount has given me some probs. First, the screws that came for the mount against the firewall, they're the right ones, but the screws that came for the engine to the mount are the same ones for the firewall, hence, too big. I had the luck of finding some other screws I had from spare, and they fit. But after drilling the holes, and I started tapping them, my tap broke inside the mount!!! :'(. It says on the manual that the engine's front thing (behind the spinner) should be 4 1/2 inches i think from the firewall, but with my Saito 91 its 5 3/4 or so. Also, the engine mount is positioned at a left downward 45 degrees, (diagonally down), and I have to cut the cowling to accept the engine, I'm thinking about making new holes on the firewall and installing new blind nuts so the engine's upside down, or with an angle where I dont have to cut the cowling. If someone has had this or these problems please let meknow and how u worked it out. I really apreciate it. Thanks

Sounds to me like you know what you want to do but need a little re-assurance from someone, you've got mine. If it was mine I would do the same and put the Saito inverted to keep it in the cowl as much as possible. The only reason for the 45 degree down is for 2-cycle mufflers to exit in a good place, I believe. You will want to keep the 4.5" measurement from firewall to thrust washer at 4.5" even with the Saito or the cowl will not fit. Probably end up with the Saito all the back on the mount with carburetor almost touching the firewall.
Tim

I understand what you are saying, but the engine, all the way back touching the bolts, exceeds almost an inch, thats the problem, and the manual says that you have to cut the cowl. But someone at my club didn't, with a 4 stroke. I would like some help on this matter, out there? anyone with a 4 stroke on their gp stuka???? :'(

Rot, I am building a GP stuka also but putting a ST .90 in it. But last year I brought my Platt Focke Wulf 190D-9 out of retirment and Had the same problems you are. What I ended up doing was buying Sig 60 size motor mounts (made of aluminum but with no cross member behind the engine. Then I had to dremel a hole in the pressent firewall to allow the engine to move back to a reasonable prop position. Once this was all done I made a box to cover the hole I made in the firewall.

I made the box by cutting a oversize peice of 1/8 marine ply (Bass) that fit over the hole very nicely. I used 1/8X3/4 Balsa stock to space the secondary firewall from the original, I ran the grain parallel to the firewalls (because it did not require any sanding that way). Once assembled I covered all the balsa on the engine side of the box with 1/64 marine play for strength.

Good luck!
Joe

thanx
ill check that out, sounds like a good idea, i think my LHS has those mounts, thanks a lot