I agree, not ideal mounting the engedne on the suspension, but with kart length restrictions it was our best bet. We're not going to be racing this through whoop sections, mainly grassy tracks and mild woods. We test fit the chain and don't have any clearance issues. Since its static, we don't have to incorporate much chain slack. The engine was mounted above the axle instead of in front of it due to complexities with the kickstarter clearance. Also we would've had issues with the FMF expansion chamber clearing the seat. Again, I agree, lower COG would've been better, but much more complex. I don't think we're going to have stability issues though since our track width is just shy of 4ft. I talked to a kart building company and they recommended this size heim jt. It's currently being abused on one of our other karts without any issue. However it's an easy upgrade if need be.
We used the Blaster sprocket hub and very carefully welded to thick keyed end pieces. We're welding two additional bearings right around the sprocket to counteract axle flex under power. And as for the gas tank, we're going to build a rear section onto the main frame to protect the engine from rollovers. We're going to incorporate a small gallon gravity fed tank into this.
I somewhat regret posting the picture now, as it's still really far from finished. I think we're probably 65% finished so far. What you see isn't even completely welded together, just tacked in place. We still need to heavily brace everything and create a tower for the rear adjustable motor mount. You make some good points, and in an ideal world with unlimited time and resources we'd do it differently. None the less, I think the finished product will be tons of fun.
I called my engine builder today and he thinks something's flukey with my test. He asked me to measure piston to head clearance with an end of solder. He then recommended that I start it with some 105 octane in it, let it idle for 5 min, and then recheck the compression. He said the head wasn't milled nearly that much, and that he though I would've been able to run 93 when it was being built. Figure I have nothing to loose by the test he recommended.
