Matthew,

One of the problems I encountered with ST engines was that the baffle in the muffler was in such close proximity to the muffler case that when exhaust residue obstructed the exiting of the exhaust it would increase the pressure to the fuel tank causing fluxuations in fuel pressure, which in turn resulted in a tuning nightmare. I drilled a 3/16 hole through the muffler case, in front of the baffle, and the problem was solved. Another indicator was that I had to constantly adjust the carb until the needle was only a 1/2 turn from being completely turned in. Just taking off the pressure line from the tank, can either prove or disprove this as being the case. It may be something to consider.

I also have experienced the brass rivet, that holds the baffle in, come loose and parts of it entering the exhaust port resulting in them being peened by the moving piston during its subsequent running! ST replaced every engine I sent them, because of this. I have also experienced the baffle rattling like a banshee...they replaced those as well. Jack and I both fly case after case of fuel through various engines and we chuckle to ourselves when we receive new engines because of our "accelerated testing". That's why I speak so highly of the O.S. .61 FX...as I've been flying mine almost exclusively since October and have put 6-7 cases through it and it continues to run like a champ! (By the way.... I did the math and I've got over 93 HOURS ((24galsx128oz/11oz)x20min./60min.) of what I believe to be the most tortourous type of flying (3D flight) on it.) Value so far..... <3 cents/minute or $1.71/hr. not bad, huh?

Peace

Downtrodden