[B40dash8]

Hello All! I bought a extra set of exhaust pipes and cut the stock mufflers off. I still have my stock exhaust system. My question is I chose to use cocktail shaker mufflers. I use them on my 78 triumph, had them on my 09 rebel 250, my previous rebel 450 and now I have them on my present 450 rebel. I installed them with the baffles it comes with but it’s too loud and the popping on decel is just way to obnoxious and loud. I plan on packing the baffles but question is why is this rebel 450 popping on decel when my other rebel didn’t with the same mufflers and baffles. If I can remember correctly I think I shimmed the needles with small washers on the previous 450…but not sure if I do that to this present one if the popping will be eliminated. It rides amazing with the stock setup. I did notice a slight exhaust leak on the left header pipe but pretty sure that wouldn’t let it pop so much on decel. Not sure if I will have to rejet the carbs or shim the needles? Does anyone have a opinion on this? I can’t do the popping on Decel. It’s way to obnoxious.
Thanks!
Below are the mufflers on my previous 450 but have the same exact ones that I’m mentioning.

 

[SoakedKarma]

could it be that the air cut valves 16048-MR4-901 were working on your other 450 carburetors thus preventing exhaust backfire?

More on the Keihin Aircut Valve www.motorcycleproject.com

www.motorcycleproject.com

 

[B40dash8]

I actually don’t know. This is the first time hearing about air cut valves. I may just richen the pilot screw and see what happens

 

[B40dash8]

Hello. I just took the cover off the air cutoff valve and noticed yellow stale gas come out of it when loosening the cover off it. I don’t see any tears in the diaphragm though. I blew out the nipple hole with compressed air to make sure there wasn’t a blockage. Not sure if the fuel in there is bad or good. Soaked karma thank you for the air cutoff read but I can’t open the “white sheet” download to read more on it.

Do you guys remove the limiting caps off the pilot air mixture screw on the bottom of the carbs to adjust them? Or is it enough to adjust with the caps on? Mine seem to be all the way to the left (clutch handle side of the engine) with the caps on against the plate. Just want to get some info before I start tinkering. I really don’t want to mess up the settings for these mufflers knowing the bike runs great with the stock mufflers and settings it’s at. Thank you!

 

[SoakedKarma]

from my little knowledge there shouldn't be any fluid in air cutoff valve..

I remove and place spare parts drawer never to be seen again
a good soldering iron may provide enough heat to soften adhesive enabling removal of cap, micro torch used carefully should work as well..

You can check the settings by counting number of turns until lightly seating the tip..

Later in the manual

You may find the complete CMX450C shop manual at link below

Google Drive: Sign-in

Access Google Drive with a Google account (for personal use) or Google Workspace account (for business use).

drive.google.com

 

[B40dash8]

So I made up my own baffles for these cocktail shaker mufflers. Pretty tough to find 1 7/8 that would fit right with the fiberglass packing I made the 1 3/4 set fit. I also tried out a washer on the end of the baffle and it quieted them down a lot. It’s just alittle louder than stock but has a different tone and doesn’t pop loud on decel. Still pops but not as loud. So far it rides good and pulls hard without any carb adjusting. It’s also 30 degrees out so I’m hoping the smoke from the exhaust is from it being so cold out.
quick video of the sound:

 

[Kreuzi]

Really like the loos of these.
Sounds nice to.

 

[B40dash8]

Hey thanks ! I try to put them on all my bikes. I had them on my rebel 250 also.

found a pic of them on the 250 but I don’t have a sound video. I sold the bike many years ago

 

[redeemer1972]

Hello All! I bought a extra set of exhaust pipes and cut the stock mufflers off. I still have my stock exhaust system. My question is I chose to use cocktail shaker mufflers. I use them on my 78 triumph, had them on my 09 rebel 250, my previous rebel 450 and now I have them on my present 450 rebel. I installed them with the baffles it comes with but it’s too loud and the popping on decel is just way to obnoxious and loud. I plan on packing the baffles but question is why is this rebel 450 popping on decel when my other rebel didn’t with the same mufflers and baffles. If I can remember correctly I think I shimmed the needles with small washers on the previous 450…but not sure if I do that to this present one if the popping will be eliminated. It rides amazing with the stock setup. I did notice a slight exhaust leak on the left header pipe but pretty sure that wouldn’t let it pop so much on decel. Not sure if I will have to rejet the carbs or shim the needles? Does anyone have a opinion on this? I can’t do the popping on Decel. It’s way to obnoxious.
Thanks!
Below are the mufflers on my previous 450 but have the same exact ones that I’m mentioning.

Up the idles to 40, you'll be fine with the back fire.
Standard pipes you can go main 120.
Open pipes, feel free to use 130's main.

And you better up the jets cause the thing will overheat your pistons due to the open pipes! Please be warned.

 

[B40dash8]

So main jet to 120 and idle jets to 40. ? Should the needle be shimmed also? I’m keeping the stock air box. It will just be the aftermarket mufflers with the baffle. I will also be putting the stock pipes back on for inspection time. Would it run good with rhe 40’s and 120 main if I put the stock pipes back on for a short amount of time?

 

[redeemer1972]

Don't touch the needle. It's happy as it is.

Trust me, it'll be fine. The airbox won't make any difference.

 

[B40dash8]

Alright thank you. When you say idle jet you mean the pilot jet correct?
I ran straight pipes on my last rebel 450 and just shimmed the needle. Luckily it never blew up lol. I’ll have to look for jets. Any suggestions or places online you like to get your jets from?

 

[redeemer1972]

Alright thank you. When you say idle jet you mean the pilot jet correct?
I ran straight pipes on my last rebel 450 and just shimmed the needle. Luckily it never blew up lol. I’ll have to look for jets. Any suggestions or places online you like to get your jets from?

I think in your case, Amazon?

 

[B40dash8]

Yeah can always get them from amazon but was thinking you guys had a special brand aside from everyone’s brand they are trying to sell

 

[flitecontrol]

Make sure any jets you buy are compatible with your carb. Mikuni jets don't fit Keihin carbs, and vice versa.

 

[B40dash8]

Thanks for the advice! I appreciate it