What is this YS?
 

I picked up a old Sig Mustang 450 and it had this motor with a tuned pipe. The side says YS 45 FS the other side says Made In Japan. The carb is really weird in that you can not see a rotating barrel. The 2 nipples went to the fuel tank, I think and I have no idea what that screw is on the bottom. Any info would help and any guess as to the value would also be appreciated. The piston and sleeve look like it was run very little if at all.

Thanks

One of the best two stroke glow engines ever produced

Info about it here. YS-45FS

1QwkSport2.5r,, look at the Prop/RPM numbers for that engine on 10% Nitro with a muffler, that's a wow for 1988

Jim

That YS .45 turns 16,400 on a 10x6 using 10% nitro and a standard muffler. That's about 1,000rpm over the average sport .45/.46 of the day using a tuned muffler like the red Jettstream.

Love mine

A friend had one in a World Models Rockwell (all yellow Bob Hoover) .46 sized P-51 and it really hauled it around nicely...

Another friend had one in 40 sized Kaos...

A nice Sport engine...Sport-Pattern...