Overview of Mac 4-into-1 Black Header/Black Canister Style Exhaust system - 204-0401
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Installation of a new exhaust system may change your motorcycles fuel-air mixture. Please consult the exhaust manufacturer directly with questions regarding any modifications that may be made during, or after, installing their product. If a jet kit or Power Commander is recommended, see the Intake/Fuel section.
Exhaust discoloration (bluing) is caused by engine conditions such as cam timing, fuel-air mixture, operating temperature, etc. It is not the result of defective manufacturing, therefore is not covered by any warranty. See Chems/Lubes section for products to help remove or prevent exhaust discoloration.
Cross reference number(s):2040401
Specs for Mac 4-into-1 Black Header/Black Canister Style Exhaust system - 204-0401
|Color - Primary||Black|
Fitment for Mac 4-into-1 Black Header/Black Canister Style Exhaust system - 204-0401See if this part fits your ride
Part 44437 fits the following machines
- 1983 Yamaha XJ750 Maxim
- 1982 Yamaha XJ750 Maxim
- 1983 Yamaha XJ750M Midnight Maxim
- 1983 Yamaha XJ750R Seca
- 1982 Yamaha XJ750R Seca
- 1981 Yamaha XJ750R Seca
- 1983 Yamaha XJ900R Seca
My main concern was with quieting the bike down from the levels of the previous system, and this does the job very well! Highway riding is easy, and the exhaust is barely even heard unless you've got the throttle open pretty far. It has a nice note at idle and looks pretty good, although a bit of water has collected in the rear lip of the exhaust and caused some rusting, though it looks like only on the baffle insert.
The paint has held up, no cracking or bubbling, and it went on fairly easily, although I had to do a little tugging to fit the pipes width-wise into the exhaust ports on the engine. The rest bolted up easily and simply.
Probably the only issue I have with this system is that draining the engine oil gets it all over the collector and I need to wipe it all down after every time, but that's something I'm willing to live with for the 4-into-1 setup.
First, Dennis Kirk great, as for delivery, UPS just sucks. Header came with no instructions and none to be found anywhere on web, my biggest concern was for the collars on the new header, they where part of the actual header, so I was not too sure if it had enough spacing to have exhaust holder seat properly on the exhaust outlet.
Took a bit of a twist and pry to get the header to correctly go around the down tube of the front of the frame, I got it around, was able to get 1 nut pack in place, then worked my way from outside to inside 1 flange at a time.
Install took maybe 30-40 minutes total time once I got old header dropped. Canister required a bit of muscle to get around collector and twisting to get into alignment with mounting holes, the kit comes with 3 hangers, all of which I did not use or need, the up-sweep of the canister aligned right with the right rear foot peg mounting hole, I did have to get a little longer bolt to finish install, but was 100% well worth the effort, I recorded video of before & after and just love the way new pipe sounds and looks, great product.