Question: After I had flown for about 3 weeks or so, my fuel tank split and fuel leaked into the foreward part of the fuselage. Any ideas what caused the tank to split?

Answer: Well you won't like to hear this... we test all our tanks before shipping and you tested it again after you assembled and installed it. So we know it was not leaking when you installed it into the ARF. We have done extensive testing and tanks that split anywhere from1 day or so to 6 months or more after installation do so when the stopper retaining screw has been overtightened. This compresses the stopper longtudinally and expands it laterally which of course is what seals the stopper in place. However, when the stopper screw is overtightened, the lateral expansion of the stopper becomes excessive and the tremendous pressure eventually splits the tank.

So... if you are using our tank or any other brand of tank, if you overtighten the stopper it will eventually split the tank or split the stopper... usually the tank. There are two ways to avoid this problem... go light on the torque... you want a seal yes but there is no need to really reaf on it. Secondly, recognizing that some folks like to use the same tools for a model airplane as a tractor (sorry but it's true), we invented our safety stopper to further reduce the chances that the tank will split.

Here is some information about our safety stopper.

Question: What does it mean in a VMAR model when I see the term "Safety Stopper"?

Answer: Beginning in mid 2004, the VMAR factory began a gradual change to a new 3 line tank with a metal overcap that aside from the convenience of a 3 line tank, helps prevent tank splitting due to overtightening of the stopper expansion bolt. The metal cap covers the end of the stopper like the older plastic disk units and also extends down and around the neck of the tank to prevent the stopper from being over compressed and splitting the tank. So, we call this new stopper and metal cap system "Safety Stopper" because it helps prevent the tank from splitting.