Time to start.

Need some help. I have a "old OS 108f sr (Bx1). Still in the box, brand new 15 years old or so.

Is it up for the job?

I ran one of these for 10 years on a 9.5 lb. Goldberg Ultimate. Great engine but BARELY adequate on the Ultimate. By todays standards I would consider it a dog. If the Yak is less than 9.5 lbs. maybe OK.

I never tried one but I hear a tuned pipe really wakes the 1.08 up.

Yes, the pipe does the thing. the airforce used that combo on the drones.

I also have a webra bulley 35cc gas from 1982......would it be a better engine? have a in fuse pipe for it too.

By the way...the bulley was in a cap 21...11.5kg!!! vsp 220. Built like a tanks.

Had a cmp extra 330l, byt lost it on the maiden due too engin failure. The only thing that was still ok after the crash was the wings.

The wings were stading next too the box with the yak in it....yup..an idea!!

The wings will fit on the yak with no problem. wingspann wil go from 1800mm too 1930mm with almost no extra weigh. Once again, im making a clone Extra yak 54

I think this wil go just fine!! Ordering covering tomorrow, and wil start the building. I wonder if i should "go large" with the engine too?

i have a nice litttle 50cc gasser twin. Wil it blend guys?

Thomas.

I have a brand new CMP Yak 54 1.40 sitting in it's box that I will tackle fairly soon.

There is no way the 1.08 will be enough for this plane.

There are plenty of threads on the CMP Yak 1.40 here, where people have gone with the largest recommended engine and found it NOT to be enough for this plane.

I originally purchased a 1.80 Magnum RFS 4 stroke for this plane, after reading the forums I've re-though this.

I'm sticking a BGX-1 on mine which SHOULD do the job. This engine should outdo a 30-35cc gasser.

Hi!

I have read al tthe threads, and understand that the 108 will be a dog.

50cc too mutch?

The OS160 FX kicks ass on this plane