Plastic End Of My Pipe Got Hot And Melted...

[glennp]

my 2011 txt pro 300 always seemed like it was running lean. Knocked on acceleration and sometimes backfired on deceleration and I would sometimes need to use the choke to start it when it was warm and it was always a finicky starter. I moved the clip down one position which was the bottom. I turned in the fuel air screw until the idle sounded good. I rode it around and the exhaust seemed a bit richer and it ran well and started better. After 30 minutes of riding the plastic end of the muffler melted and spit out the aluminum spark arrestor. I thought a richer fuel mix would make it run cooler. I use this as a trail bike and it has well over 1000 miles on it. Was this just a symptom of a clogged exhaust? Should I just clean and repack my pipe or am I missing something? Thanks!

[sirdabalot]

I've seen this before when one was run at sustained high speed on a road, I think a company made aluminium replacements.

[baldilocks]

The later ones have a stainless steel rather than aluminium exit pipe. This solves the problem as less heat transfers to the plastic according to gg. It didn't melt at the ssdt so I'm taking their word for it

[crazybond700]

I've seen this before when one was run at sustained high speed on a road, I think a company made aluminium replacements.

 

I think the website of cambs trial center has/had them.

[lineaway]

 You need a larger pilot jet for your running problems. The plastic melting was caused by the spark arrestor.