[]Does the Saito 100 have some kind of inherent fuel flow problem. Is there a real need to buy a pump/regulator if the tank is located at the firewall of the UCD 60? It seems that some people may be trying to solve a problem that doesn't exist. The Saito 72 in my UCD 46 has no such problem.

If the tank is moved to some location that is distant from the engine a pump/regulator may be necessary. Is it correct to assume that some fliers relocate the tank farther back in the UCD fuselage to achieve a more favorable CG location for 3d flying?

I moved the CG farther back in one of my UCD 60's (I have two) by moving the battery to the rear of the fuselage in a hatch I made in the bottom. In this way I avoided having to move the tank, the throttle servo, the receiver and having to buy a regulator for $43.00 plus shipping. I did notice that the plane becomes a little squirrelly with 3d elevator throws.

My two UCD 60's are powered by OS 91 2-strokes. The OS 2-stroke with its giant muffler weighs 24.3 oz which is more than the Saito 100 4-stroke. A Saito in the nose may move the CG a little farther rearward.

My next engine purchase may be a Saito 100 4-stroke and I was hoping to use it without buying any additional gadgetry to attach to it.