I  just reassembled one of my Sure Start engines. Most but not all of the engines I purchased had a gasket on the back of the crankcase. The reed retainer on some of the engines were just a small cylindrical cap that snapped over the venturi hole. On some of the 8cc tank backs I purchased, the reed retainer had the gasket built into it. My concern was the amount of end play the connecting rod had on the crank pin. Is there any advantage to using one vs. the other. Call me old school, but I'm a fan of gaskets.  I would assemble the engine without the cylinder head and look down inside. In 3 examples the differences were detected by eye.I have one that I've been running and I'm not sure how the rod stays on.  In the event that this plastic wears, I'm sure the piston is going to do something I'm not going to like. Would honing the back of the case take care of this? In addition, Will this increase internal crankcase pressure. When I run this engine the reed has a tendency to deform into the venturi hole.The reed seems to have a lot of excessive play all around. The reed doesn't seem to have the support behind  it as the older metal tank backs gave. But, then again the older engines didn't cost 8$. The particular reed I'm using appears to be aluminum. I've had good but short success with the mylar ones. I guess I'm always in search of ways to improve.                Ken Cook

            Alan, what I was refering to was the con-rod play from front to back on the crank pin itself. I have 2 different engines on hand here. One uses no gasket, the other does. These are both Sure Start engines. One uses a cap to hold the reed on and stays within itself upon disassembly while the other is a retainer-gasket. The protruding portion of the backplate or tank that extends into the crankcase also serves to hold the con-rod onto the crankpin. I know this can be hard to explain. Picture holding the assembled engine in your hand, then pull on the prop. This to me is known as crankshaft end play. What is puzzling to me is that this particular engine has a very normal amount of end play but yet its amazing to me whats holding the con-rod onto the crankpin. The distance between the back of the pin and the tank back is so excessive I could almost slip the con-rod off with the engine assembled. Its as if the crankcase depth  is slightly larger. I was going to dissasemble both engine and lay them on their backs and measure from table to top of prop driver to check. I've heard of people flattening the backs of their crankcases for a nice fit to prevent leaks. What concerns me is this engine is the best running one I own. Like the rest of us I own several Cox engines but it seems that you get a real good one out of several. I surely don't want to see this one hand grenade. I just wanted to know if removing a few thousandths off of the back of the case would tighten up the clearance on the con-rod without any other affects.   Ken Cook