Topic: Exhaust Photo Reference Library.

[BenelliSEI]

FUBAR. Made in California, early ‘70’s.

[BenelliSEI]

FUBAR’s magazine ads were even better than the pipes!

[Schnell]

RC Russ Collins 4into1

[Tom R]

77 cb750k head pipes with hollow reverse cones from eBay. I have some 1-1/2” perforated pipe to baffle them a bit.
I started putting this together when I was going to race my cB750 in the production heavyweight class, which requires a 4-4.
Instead I race my 400f in production lightweight and bump up into heavyweight… the 400f does just fine in both classes.
If I ever get this bike back together I think I’m still going to run these.

[Nightshift]

77 cb750k head pipes with hollow reverse cones from eBay. I have some 1-1/2” perforated pipe to baffle them a bit.
I started putting this together when I was going to race my cB750 in the production heavyweight class, which requires a 4-4.
Instead I race my 400f in production lightweight and bump up into heavyweight… the 400f does just fine in both classes.
If I ever get this bike back together I think I’m still going to run these.

Tom, who did you buy these 4-4 from? I don't see them on FleaBay. I need 2 sets. Bill

[Tom R]

https://www.bmikarts.com/Reverse-Megaphone-Cone-Muffler_p_5227.html

They’re hollow. Probably too loud to stay under 100db for racing even.