Author Topic: IT250J OEM silencer, what's inside?  (Read 2009 times)

0 Members and 1 Guest are viewing this topic.

Offline dont

  • Yama-Idol
  • *****
  • Posts: 502
Re: IT250J OEM silencer, what's inside?
« Reply #20 on: December 22, 2018, 07:28:52 AM »
^^ sounds like what I did for a pipe on my it175j. For the end cap did you use the lid of a glass chutney jar?
What goes up must come down, unless you broke a 'rod 😞

Offline JungleBiker

  • Yama-Legend
  • ***
  • Posts: 131
Re: IT250J OEM silencer, what's inside?
« Reply #21 on: February 01, 2019, 06:58:05 PM »

     Ha!  No, I did that sort of thing when I was a kid, then found that it didn't hold up very well over the long term.  Now I have access to better tools and materials than I did now, so I actually made the end cap out of a piece of flat steel, I forget how thick it was, maybe 4mm?  The perforated sheet I used for the core was stainless.

       Interestingly, I found that the exhaust was significantly louder when the timing was retarded too far--my theory is that when the timing is retarded too far, less of the fuel-air charge has been burned by the time the exhaust port is uncovered, and more unburnt, burning gasses enter the pipe, possibly under high pressure and thus make more noise?  A louder "pop" per exhaust cycle, as it were.
--1982 Yamaha IT250J, was a wreck, now rapidly improving!
--1967 Norton P11 (US project bike)
--1985 Armstrong MT500 (UK rider)
--1985 Honda XR600/628R (PNG daily rider)
--1998 HD XL883 (soon! May be the only Harley in PNG. Will be scrambled)
-- lots of other junk spread across several US states and two big islands