Nitro fuel lines: when to replace them?

Good Evening. I had a rather rough time at my field this afternoon, with two flame-outs on my trusty OS .61 SF. The engine is in a Hobbistar, which has been my primary plane since last September. The first time the engine flamed out, I ended up gliding the plane into a gully just beyond the runway. When I got to it, I noticed that the fuel pressure line had come off the muffler, so I figured it must have been the loss of back pressure, upon the line coming off the muffler, which caused the flame-out. (I found that the glow plug was still intact and functional.) Since I noticed the pressure line now easily came off the nipple, I snipped off 1/4 inch of the line and put it back onto the nipple. The next flight was even worse than the first. I noticed a change in the tone of the engine exhaust, and I thought I saw something shiny fall off the plane in flight. I wasn't sure at the time what exactly it was, but I would eventually find out! Once again, the engine ran erratically, so my first thought was, I better get it down. The engine dead-sticked a second time, but this time I was able to land it on the runway. When I got to the plane, I noticed the muffler was gone!!! I immediately called my LHS, and the good people there have put in a special order for a new muffler for the engine. It should arrive sometime next week.

This adventure got me wondering if silicone nitro fuel lines have a finite life span. Since I have been using the same two lines (supply and pressure) on this plane for about 10 months now, should I consider replacing them with fresh tubes? Please let me know your thoughts.

Thanks, Harry Sanchez

Reply to
Harry Sanchez
Loading thread data ...

Harry, As a general rule I replace the fuel lines each season. I look at it as cheap insurance, like using new rubber bands on the wing each time. I have found that over time the lines can develop small hairline cracks where ever they connect to the fuel tank, or the carb/muffler nipples. These can be very hard to detect but will cause your engine to have erratic idle problems, pre-mature flameouts etc. I just figure that $3 for fuel lines is much cheaper than a new plane.


Reply to

On Thu, 23 Jun 2005 23:15:18 -0700, Harry Sanchez wrote in :

I doubt the tubes are your problem.

I'm not good at replacing lines until they really feel substantially different from fresh lines. On the other hand, a friend of mine replaces all of his lines every spring.

I have found a few clunk lines that were nearly rotten with age, so I suppose I oughta be a little more pro-active.

I also oughta lose about 40 pounds One of These Days.


Reply to
Martin X. Moleski, SJ

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.