muffler gets so hot that the pressure line breaks need ideas

[freddycanfly]

runnin os 91-hz with hatori pipe

motor seems pretty spot on with tuning she runs like a dream with 80% gov or 1915 rpm

but at the end of every flight if i pull one the pressure line even slightly it just tears leaving some line on the muffler nipple ????

it makes me scared to fly dont want it to have it detatch in flight,

any ideas please ?????

[saeed09]

Am not sure if the muffler being too hot is the reason. To me it looks like you have a bad silicon line. I normally fix my lines free from tension.

[freddycanfly]

well there is no tension on the lines at all ???

i feel the nipple on the muffler as soon as i land and it is pretty hot i cant even touch it lol

then if i pull on the line to say dessconect it from the muffler it just snaps its weird i have tried multple fuel tubes and it keeps doing it this is the first time i have had this problem its kinda random lol

[bloftin]

Replace the pressure line with new tubing and see if that helps. Have you measured your head temp to ensure your not running lean (hot)?

[marekfilip]

I had the same problem. Make sure the muffler does not leak any pressure. I put some high temp epoxy between the engine and muffler and also on the pressure line outlet. This solved the problem.

[KC36330]

silicone tubing will hold up to a much higher temp then the muff should ever get to even if you're running it lean enough to destroy the engine, your line is deteriorated and needs replacing.

[saeed09]

Also i think you dont need to worry and pull the line after every flight when its hot. Some nipples are tight fit with fuel lines especially when they are exposed to heat. I have a yellow fuel line which gets very tight on nipples. If you fix it even on a fuel tanks nipple, after some few minutes if you try to pull it so hard it will just break off just on top of the nipple. This is a very good line but the fact of pulling it will cause a weak point and break off.

[chris982]

I think your line is worn. I had an issue similar to that, but in my fuel tank. I was loosing pressure and my engine was running lean. I found my clunk line nearly rotting off. You have to replace those every season.

[Crash549]

The Align tubing(light green color) would get hard and brittle on my muffler and I switched to dubro line (light blue color)and it has lasted quite a while. It's ALOT thicker and a little hard to run through the frame grommets but it has been working for me since last summer