removing baffles 1980 honda CB650

Matthebrute · 05-23-2012, 08:39 PM

hey guys, my bike is getting closer and closer to where i want it but it sounds like a dam scooter!!!

i had both mufflers off and it sounded 1/2 way between chit and nice and loud.

i was wondering if theres any way i can remove SOME of the baffles to get the sound up but keep it sounding "good" as well.

there are 3 allen nuts on the end of each pipe, i have taken them off and tried to remove the guts of the muffler and no luck without risking bending something.

any suggestions?

thanks
Matt

Dodsfall · 05-23-2012, 08:57 PM

Managing to attach some sort of aftermarket slip-on muffler may be the most economical way to do that.

Remember that changing the exhaust will usually require a balanced change to the intake to avoid potentially serious engine damage.

Matthebrute · 05-23-2012, 09:35 PM

aftermarket pipes are a dream

i am broke lol. i did manage to get myself a free carb sync tool (off this site) now i just need the valve adjustment tool and im going to do the sync and adjustment at same time. so this may be a project for when i do them 2 processes which is fine by me, any tips/tricks that i need to know to adjust the intake as well? is that just adjusting the jets? because when i take the carbs off to clean and sync i can adjust the jets all at the same time.

Dodsfall · 05-23-2012, 09:49 PM

It's done by replacing the jets with new ones of a larger diameter.

They really need to be done as a set with a new exhaust, since replacing the jets with a larger size without a change in exhaust back pressure will only make the engine run rich, run badly, and likely foul the plugs from fuel not being burned completely.

Most aftermarket exhaust companies have charts to show which jet size will work best with their products on a certain engine.

A home-made exhaust mod can theoretically be dialed in with some guesswork and a few different sizes of jets on hand, then some experimentation by checking spark plug color and condition during trial runs. It's somewhat labor-intensive, but it can get the mixture pretty close.

Trial runs on a dyno can tune the intake and exhaust the best, allowing the fuel mixture to be perfectly matched to the new exhaust pressure. This requires rather expensive machinery and someone who knows how to operate it.

Matthebrute · 05-23-2012, 10:07 PM

dont think ill be picking one of them up anytime soon....i do believe the pipes are not "stock" and i think this motor has some miles on it. needs to be thouroughly cleaned and fine tuned. or just beat on till it dies.....

im really not sure where i want to go with this bike. it really needs alot of carb/engine work. i think it has been poorly maintained and probably beat on. not too sure if its worth all the work...sometimes can be a lost cause and by "fixing" them you actually make em run worse because they are so used to being neglected....the air filter was just terrible, never seen anything like it (on a car, first bike filter i have replaced) oily and just caked in chit.

anyways im rambling....

Matt

Matthebrute · 05-23-2012, 10:10 PM

oh and i removed the exaust from one side and the valves were caked in white soot/corosion so somethings going on there too (i think) or is that what a 32 year old exaust valve stem looks like normally?

still rambling...its late, few beers in

Dodsfall · 05-23-2012, 10:17 PM

You can get a rough idea of how your mixture is set by checking the spark plug electrodes.

Black and sooty=too rich
Light tan deposits=perfect
Grayish deposits= a bit lean, but ok
White deposits=lean
Melted electrodes or insulators=way too lean

Matthebrute · 05-24-2012, 12:18 PM

ok great..thanks for the info ill keep posted on how i make out with it.

Batboy · 06-17-2012, 03:16 AM

I've heard of guys cutting the last couple of inches off of their exhaust pipe in order to pull out the baffles, or using a 1.5" metal Hole Saw on the end of an power drill to cut around the plate at the end of the exhaust. Both seem to be pretty cheap if you have the tools. The other option is to buy straight pipes or inserts. I guess if you try to mod and it screws them up you would have to buy new ones anyways.

05-23-2012, 08:39 PM	#1
Matthebrute Master At Arms Join Date: May 2012 Location: Skowhegan, ME Posts: 109	removing baffles 1980 honda CB650 hey guys, my bike is getting closer and closer to where i want it but it sounds like a dam scooter!!! i had both mufflers off and it sounded 1/2 way between chit and nice and loud. i was wondering if theres any way i can remove SOME of the baffles to get the sound up but keep it sounding "good" as well. there are 3 allen nuts on the end of each pipe, i have taken them off and tried to remove the guts of the muffler and no luck without risking bending something. any suggestions? thanks Matt

05-23-2012, 08:57 PM	#2
Dodsfall Administrator Join Date: May 2008 Location: Illinois, USA Posts: 15,834	Managing to attach some sort of aftermarket slip-on muffler may be the most economical way to do that. Remember that changing the exhaust will usually require a balanced change to the intake to avoid potentially serious engine damage. __________________ 2008 XL1200R To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

05-23-2012, 10:17 PM	#7
Dodsfall Administrator Join Date: May 2008 Location: Illinois, USA Posts: 15,834	You can get a rough idea of how your mixture is set by checking the spark plug electrodes. Black and sooty=too rich Light tan deposits=perfect Grayish deposits= a bit lean, but ok White deposits=lean Melted electrodes or insulators=way too lean __________________ 2008 XL1200R To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.

06-17-2012, 03:16 AM	#9
Batboy Newbie Join Date: Jun 2012 Location: Portland, Or Posts: 4	Exhaust fix I've heard of guys cutting the last couple of inches off of their exhaust pipe in order to pull out the baffles, or using a 1.5" metal Hole Saw on the end of an power drill to cut around the plate at the end of the exhaust. Both seem to be pretty cheap if you have the tools. The other option is to buy straight pipes or inserts. I guess if you try to mod and it screws them up you would have to buy new ones anyways.

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

05-23-2012, 09:35 PM	#3
Matthebrute Master At Arms Join Date: May 2012 Location: Skowhegan, ME Posts: 109	aftermarket pipes are a dream i am broke lol. i did manage to get myself a free carb sync tool (off this site) now i just need the valve adjustment tool and im going to do the sync and adjustment at same time. so this may be a project for when i do them 2 processes which is fine by me, any tips/tricks that i need to know to adjust the intake as well? is that just adjusting the jets? because when i take the carbs off to clean and sync i can adjust the jets all at the same time.

05-23-2012, 10:07 PM	#5
Matthebrute Master At Arms Join Date: May 2012 Location: Skowhegan, ME Posts: 109	dont think ill be picking one of them up anytime soon....i do believe the pipes are not "stock" and i think this motor has some miles on it. needs to be thouroughly cleaned and fine tuned. or just beat on till it dies..... im really not sure where i want to go with this bike. it really needs alot of carb/engine work. i think it has been poorly maintained and probably beat on. not too sure if its worth all the work...sometimes can be a lost cause and by "fixing" them you actually make em run worse because they are so used to being neglected....the air filter was just terrible, never seen anything like it (on a car, first bike filter i have replaced) oily and just caked in chit. anyways im rambling.... Matt

05-23-2012, 10:10 PM	#6
Matthebrute Master At Arms Join Date: May 2012 Location: Skowhegan, ME Posts: 109	oh and i removed the exaust from one side and the valves were caked in white soot/corosion so somethings going on there too (i think) or is that what a 32 year old exaust valve stem looks like normally? still rambling...its late, few beers in

05-24-2012, 12:18 PM	#8
Matthebrute Master At Arms Join Date: May 2012 Location: Skowhegan, ME Posts: 109	ok great..thanks for the info ill keep posted on how i make out with it.