Go Back   Motorcycle Forum > Motorcycle.Com General Discussion > Motorcycle Mods and Maintenance

Reply
 
Thread Tools
Old 06-22-2009, 09:47 AM   #1
BikeRider12345
Registered Member
 
Join Date: Jun 2009
Posts: 6
Default Noise out of the muffler

I have a 1980 Honda CB750K. It starts right up, but it sounds like air is escaping from the mufflers every once and awhile. What could that be from?
BikeRider12345 is offline   Reply With Quote

Sponsored Links Remove Advertisements
Motorcycle Forum
Advertisement
Old 06-22-2009, 09:56 AM   #2
pushrod
Founding Member
 
pushrod's Avatar
 
Join Date: Nov 2001
Location: Baja 'Bama
Posts: 3,642
Default

Assuming you don't mean the air is coming out of the back, where do you think the 'leak' is?

At the head, midbody, joint(s), etc.
__________________
You would not understand,
this is not how I am...

I have become -
Comfortably Numb.
pushrod is offline   Reply With Quote
Old 06-22-2009, 11:04 AM   #3
BikeRider12345
Registered Member
 
Join Date: Jun 2009
Posts: 6
Default

It is coming out of the back of the muffler. I should have been more specific. It comes in short bursts, it sounds like an air compressor going off. Just happens every 15 seconds or so. Is it a carb timing issue?
BikeRider12345 is offline   Reply With Quote
Old 06-22-2009, 12:12 PM   #4
MOKE1K
Registered Member
 
MOKE1K's Avatar
 
Join Date: Jul 2008
Location: Kalapana, Big Island
Posts: 3,994
Cool

Ah, ahem,...I am lost?
__________________
"YOU CAN'T BOLT ON SKILL"
MOKE1K is offline   Reply With Quote
Old 06-22-2009, 12:55 PM   #5
BikeRider12345
Registered Member
 
Join Date: Jun 2009
Posts: 6
Default

When the bike is running, I will here a noise come out of the muffler about every 15 seconds that sounds like an air compressor. Just like a burst of air. That is the best I can explain it. Not a normal sound for an exhaust. I am just wondering if it is a synching issue or what. I think it is only the left muffler.
BikeRider12345 is offline   Reply With Quote
Old 06-22-2009, 12:56 PM   #6
seruzawa
The Toad

 
seruzawa's Avatar
 
Join Date: Nov 2001
Location: 8501 ft.
Posts: 17,461
Default

Quote:
Originally Posted by BikeRider12345 View Post
When the bike is running, I will here a noise come out of the muffler about every 15 seconds that sounds like an air compressor. Just like a burst of air. That is the best I can explain it. Not a normal sound for an exhaust. I am just wondering if it is a synching issue or what. I think it is only the left muffler.
I'd pull the muffler off and see if something has come loose or is blocking it.
__________________
"Make no mistake, Communism lost a big argument - one we know today as the 20th century."
seruzawa is offline   Reply With Quote
Old 06-22-2009, 01:55 PM   #7
mscuddy
MODERATOR X

 
mscuddy's Avatar
 
Join Date: Jun 2007
Location: Next to my still checkin the temp.
Posts: 5,448
Default

Buy a Kerker reproduciton for anout $150.00. The "F" model had that big goofy pipe on it that had more crap in it than my roll-a-way filled with jig saw puzzles. Not only will it perform better, you'll get that 70 lb. salami off the left side and it will handle better too.

Face it, your 25 plus old exhaust pipe has more holes in it than Bill Clinton's tenor sax. It might sound better but that's the price we pay sometimes.
__________________
A gun is a tool, Marian; no better or no worse than any other tool: an axe, a shovel or anything. A gun is as good or as bad as the man using it. Remember that.
mscuddy is offline   Reply With Quote
Old 06-22-2009, 03:28 PM   #8
acecycleins
Founding Member
 
acecycleins's Avatar
 
Join Date: Jun 2007
Location: North Georgia
Posts: 4,129
Default

Is this KP messing with you guys.

What is a motor- an air compressor with a purpose. Air, fuel, ignition- throttle and so it goes.

Check the seating at the motor at the header. I used to have a old Bonni that had a crack at the top of the pipe. It would puff very little smoke out of that hole, but you could hear it when standing behind the bike.
__________________
"Slack" - a state of being in which everything flows smoothly.....a frame of mind so at ease that the universe naturally cooperates.
acecycleins is offline   Reply With Quote
Old 06-22-2009, 04:42 PM   #9
MOKE1K
Registered Member
 
MOKE1K's Avatar
 
Join Date: Jul 2008
Location: Kalapana, Big Island
Posts: 3,994
Cool

I Know Its Your Muffler Bearings!!!
__________________
"YOU CAN'T BOLT ON SKILL"
MOKE1K is offline   Reply With Quote
Old 06-22-2009, 04:46 PM   #10
seruzawa
The Toad

 
seruzawa's Avatar
 
Join Date: Nov 2001
Location: 8501 ft.
Posts: 17,461
Default

Quote:
Originally Posted by acecycleins View Post
Is this KP messing with you guys.

What is a motor- an air compressor with a purpose. Air, fuel, ignition- throttle and so it goes.

Check the seating at the motor at the header. I used to have a old Bonni that had a crack at the top of the pipe. It would puff very little smoke out of that hole, but you could hear it when standing behind the bike.
IP sez Texas.
__________________
"Make no mistake, Communism lost a big argument - one we know today as the 20th century."
seruzawa is offline   Reply With Quote
Reply


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off