Dr1, I've used two different make filters and have never had a problem with them. In fact, on my four strokes, I use two. One between the muffler and the tank and the other between the carb and tank. I've never had one leak.

There really isn't anything wrong with the soft tubing. I would check the line size. It should fit very snugly on a piece of 1/8" brass tubing. If it is loose, it is to big.

This may be a comment from way out in left field, but is you tubing snug between the tank and engine, IE is there a bit of extra length. If you have things to tight on length, it will pull off. You want you tubing at least 1/2" longer than needed. You don't want any kinks in it either, so take that into consideration when cutting to length. I put the tubing on the tank and leave a foot or more out the front of the plane. Then after eveything is mounted, I route the tubing to the nipple on the engine making sure there is not kinks in the bends and then cut it 1/2" longer. Once I have it to length, then I figure where I want the filter and cut the tubing there, one cut which gives me a bit extra length again.

Two reasons for the extra length. First it prevents the kinks that shut off fuel flow. Second most tubing failures are right at the nipple or tank tubing. If you have a bit extra line in the hookup, you can usually fix a leak at the field and do a full up repair later.

In addition to the zip ties, you can cut a short, 1/8" long, piece of tubing and put it over the end of your main tubing. Put your main on and the slide the short piece up and onto the nipple. Nothing slips by this.

Don

Added" A little extra length is good, al lot is bad. You don't want the tubing flaying around in the air stream.