HI I'm building a kit sig 4* 60 and I'm to the point of installing the motor mount to the firewall and building the fuselage around it. the mount is installed by using hidden nuts type setup. the problem is, I wouldn't be getting the O.S 61 FX 2-stroke until Christmas Is there anyway I could continue building the plane without the motor? I would like to use the motor mount that came with the Sig kit. Also would this be the right motor for this plane? thank you

Yes, you can go on with your building... Just mount the fire wall and motor mount as per the instructions. When you put the blind nuts in place, glue them in. Put some petroleum jelly (Vaseline) in the blind nut to protect the threads from the glue. When you run the bolt in, after the glue is dry, the petroleum jelly will be pushed out. When you get your .61 FX mount it to the motor mount and check the balance of the plane. Just make sure your motor mount is for a .61 engine. You can tell some times by looking at the back of the motor mount. You will see something like 40-60 or 40-70 or 60-70 or 60-90. You get the point. If your mount is for a 40-60 size, you may want to take it to your LHS and ask to barrow one of the .61FX motors in the case to see if your mount is wide enough for the FX. The .61 FX crank case is just a hair wider than the other os .61 engines and it may be a tight fit. Most hobby shops will be more than happy to let you test fit your motor mount to a display motor.

I hope I was of help!

Good Luck, Happy building!

Hi Mikie, I am using a 61FX and APC12x6 with great results. I replaced the stock mount with a Dave Brown. I also have 2deg of right thrust built in using an Ernst thrust plate sandwiched between the mount and firewall. To answer your question : you can mount your engine mount on the firewall and continue with the rest of the fuse build. When you get the engine, find the best position on the mount beam to give you the right cg, and mark the bolt holes. Remove the mount for drilling. I have a 1400mah NiCd under the tank to get the cg at the rearmost position of the main spar without any additional lead weight. The 4*60 builds tail heavy. Search this forum for the many good threads on building techniques and color schemes for this popular kit

You can also go to the OS engines web site(osengines.com) and get the dimensions for the motor Santa is bringing you. That should tell you how far apart to mount the beams of your engine mount(I'm assuming the 60 size uses the same style of mount as the 40 size...two black nylon "T" shaped beams). You might want to hold off drilling the mount to accept the bolts for the motor until you get it... that way you can move the motor forwards/backwards a bit to help get the CG in the right spot