Author Topic: What's the diff with 4-1 or 4-2-1 exhausts?  (Read 599 times)

0 Members and 2 Guests are viewing this topic.

Offline messeduptriple

  • Hot Shot
  • ***
  • Posts: 677
What's the diff with 4-1 or 4-2-1 exhausts?
« on: January 20, 2012, 01:35:39 AM »
Ok, I'm planning on buying a new exhaust for the beast... But now I'm curious what's the difference with these exhausts?? I'm running stock motor, stock everything. 550 76.
Any suggestions what will sound and run better? Also what do I need to do if I do change to these exhausts if anything to the carbs, airbox or stuff like that? I'm total new to these so any info is greatly appreciated. Thanks

Sent from my PC36100 using Tapatalk

Offline trueblue

  • A person who has had many interesting experiences, some of which are true, is known as an
  • Old Timer
  • ******
  • Posts: 3,124
Re: What's the diff with 4-1 or 4-2-1 exhausts?
« Reply #1 on: January 20, 2012, 01:49:04 AM »
4-1 and 4-2-1 scavenge at different rates, one works better in the lower rev range, and the other is more efficient in the higher revs, which way around they work I can't remember... I think the 4-2-1 work better at higher revs, but how much difference you'll notice on a 550 I can't say, but I would say minimal.
1979 CB650Z
Nothing can be idiot proofed, the world keeps producing better idiots.
Electronic Guages for your SOHC 4

Offline messeduptriple

  • Hot Shot
  • ***
  • Posts: 677
Re: What's the diff with 4-1 or 4-2-1 exhausts?
« Reply #2 on: January 20, 2012, 06:59:29 AM »
Cool. Thanks

Sent from my PC36100 using Tapatalk