Welcome, Guest
Username: Password: Remember me
  • Page:
  • 1
  • 2

TOPIC:

Help ID 4/2 exhause, please. 22 Mar 2024 01:59 #896733

  • Wookie58
  • Wookie58's Avatar
  • Offline
  • Moderator
  • Posts: 3140
  • Thank you received: 1751

MODS - just realized that slmjim posted the wrong OD of the retaining collars in the OP as 50mm. Oops...

They are 40mm.

Please correct or, enable edit & we will do so early AM tomorrow.

Thx.

Good Ridin'
slmjim & Z1BEBE
Done 
The following user(s) said Thank You: slmjim+Z1BEBE

Please Log in or Create an account to join the conversation.

Help ID 4/2 exhause, please. 24 Mar 2024 05:16 #896822

  • slmjim+Z1BEBE
  • slmjim+Z1BEBE's Avatar Topic Author
  • Offline
  • User
  • Enjoy Life! IT HAS AN EXPIRATION DATE!
  • Posts: 1112
  • Thank you received: 588

I've been meaning to pull the ancient 4-into-1 off the '81 GPz550. Let me see if that can happen this weekend; if so, I can get some measurements.
 
Thanks Scott.  Perhaps there's a 4-2 system in your GPZ-550's future at a price you can't resist?

Good Ridin'
slmjim & Z1BEBE
A biker looks at your engine and chrome.
A Rider looks at your odometer and tags.

1972 Z1 x2
1974 Z1-A x2
1975 Z1-B x2
1993 CB 750 Nighthawk x2
2009 ST1300A

www.kawasaki-z-classik.com
An enthusiast's forum focused exclusively
on all things Z1, Z2 and KZ900.

The following user(s) said Thank You: Nerdy

Please Log in or Create an account to join the conversation.

Help ID 4/2 exhause, please. 24 Mar 2024 19:29 #896857

  • Nerdy
  • Nerdy's Avatar
  • Offline
  • Sustaining Member
  • Posts: 995
  • Thank you received: 368

Thanks Scott.  Perhaps there's a 4-2 system in your GPZ-550's future at a price you can't resist?
 

You read my mind

Regrettably I didn't get into the shop this weekend, but had an idea. Tucked away in the basement are two new-in-box MAC 4-into-1s for the GPz. I can get one of them open and take some detailed measurements.
1979 KZ400 Gifted to a couple of nephews
1967 Yamaha YCS1 Bonanza
1980 KZ440B
1981 Yamaha XT250H
1981 KZ440 LTD project bike
1981 GPz550
2013 Yamaha FZ6R
The following user(s) said Thank You: slmjim+Z1BEBE

Please Log in or Create an account to join the conversation.

Help ID 4/2 exhause, please. 02 Apr 2024 14:15 #897180

  • Nerdy
  • Nerdy's Avatar
  • Offline
  • Sustaining Member
  • Posts: 995
  • Thank you received: 368
Okay, I finally made it down to the shop Here are the measurements from the newer of the two MAC pipes:

- the flange diameter at the head (the part that sits on the exhaust gasket) is 38mm

- the outside-to-outside of the 3-4 headers (close to the head) is 119mm

- the inside-to-inside distance between 3-4 is 41mm

- the center-to-center of 3-4 at the flange is 83mm

I did these using a really basic set of Harbor Freight calipers but they should be pretty close. The center-to-center might be a little suspect since I eyeballed the caliper points.

EDIT: let's put slmjim's measurements in here, too

Center-to-center of 1/2 and 3/4 headpipes is ~88mm -  ~3 1/4in.
OD of headpipe collars is. 40mm
OD of collector(s) out is 48mm.
OD of connector pipes is 48mm.


The verdict seems to be that the exhaust in question will not fit a 1981 GPz550. Dang it. :(
1979 KZ400 Gifted to a couple of nephews
1967 Yamaha YCS1 Bonanza
1980 KZ440B
1981 Yamaha XT250H
1981 KZ440 LTD project bike
1981 GPz550
2013 Yamaha FZ6R

Please Log in or Create an account to join the conversation.

Last edit: by Nerdy.
  • Page:
  • 1
  • 2
Powered by Kunena Forum