Acceleration control rings, exhaust choking and engine heating, and fuel and oil mixes

Newbee,

Welcome!

I've never used a Cox muffler or exhaust throttle ring, as our field is bordered on the west side by a major freeway (I-5). The traffic noise is almost always louder then any of our engines, so no mufflers are required or needed!

Talk to some of the others here who regularly use Cox throttles, and I think you will hear that the smaller Cox engines never overheat at idle, and run just fine at full throttle (with normal Nitro levels). Your 25 percent SIG fuel should be just fine, but I question those who claim full synthetic lube works fine. I would not worry about a small amount of synthetic (5 to 10 percent), as I think the remaining Castor oil will still lube the plain case bearings and ball joint.

The only heating problems using 25 percent or less Nitro were seen when Pay Load was still popular, and where larger props (7" to 8" diameter) were used for best economy and thrust. You could always use a 5 fin head from Bernie, if heating does concern you.

I use a common hand hair dryer to soften dried Castor oil, but even those can damage plastic parts, so best to remove the plastic parts first. Fuel soaking almost always frees up stuck engines, unless there is rust in the cylinder bore.

One thing I hate is Cox engine wrenches used anywhere near Cox exhaust ports, as the sheared edges play hell with cylinders if not padded in some way. I've heard others simply pad the wrench edges with masking or plastic tape, but I much prefer leather strap wrenches for holding cylinders in place while removing heads, or removing the cylinder from the case.

Good luck with your engine!

Bill