Just got my new YS 70S from Hobby Barn. They have relocated the regulator aft mounted between the cylinder and the carb. The HSN actually goes through the regulator structure. Both fuel lines are pointing aft which I think is an improvement. The regulator cover is held on by two small screws and I think that is an improvment over the press fit used on the 63s. Otherwise, it looks the same as the 63/53 carb wise.

I am looking forward to using this spiffy new engine.

Chip</p>

Hi Chip...You're gonna LOVE it....Yes, the reg. is a complete new design...The inlet valve is now triggered with a "Rocker/Arm". the other end of which is activated by the diaphragm...Similar to the "Walbro...Tillitson...Zama" diaphragm metered gas carbs

Looks like this:

http://www.keimod.com/shop/popup_add...roducts_id=566

Same reg. as the ST 50/56 even with the cutout for the needle valve seat on the wrong side.