idle sound - sounds like valve closing under throttle

Joined
Jan 15, 2014
Messages
182
Location
Canada
Hello guys, 07' with 52,000kms and I just did the valve check this winter. All within spec....put everything back together as was found. I'm now getting a deeper rumble (exhaust note) when idling.....give it some throttle and it sounds like a valve (not exhaust or intake kind) popping closed (or open) and the rumble sound goes away. Rumble sound is very evident at front of engine. With any kind of throttle it sounds normal....right after I hear that popping sound. It's not backfiring it just sounds like something just shut. I know very vague description but thats the best I can do .....not sure if video will pick it up. Any thoughts? Runs fine....just this annoying rumble off of throttle.
 
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PFD023
Joined
Jan 15, 2014
Messages
182
Location
Canada
Can't hear the flap closing sound.....But you can hear the deeper rumble.
 
Joined
Sep 4, 2013
Messages
8,114
Location
Cleveland
Bike
2010 ST1300
Stethoscope time. If you only checked the valves, then you didn't touch the cam chains, right? Simply turning the engine over by hand and using a feeler gauge should not have any effect at all on the engine. Almost sounds like an exhaust issue to me - the burbling.
 
Joined
Sep 3, 2016
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1,041
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LSAC, AB & Indio, CA
Bike
2005/06/07 ST1300
To me it sounds like a moving part of the valve train is actually hitting the valve cover and therefore the hollow sound. I am looking at photos in my manual and it appears there are no rockers, but what about a cam lobe on the holder or chain. Not so sure but that sound is familiar in automotive to be that.
 
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PFD023
Joined
Jan 15, 2014
Messages
182
Location
Canada
Stethoscope time. If you only checked the valves, then you didn't touch the cam chains, right? Simply turning the engine over by hand and using a feeler gauge should not have any effect at all on the engine. Almost sounds like an exhaust issue to me - the burbling.
correct....didn't touch the cam chains
 
Joined
Aug 8, 2015
Messages
471
Location
CT USA
Bike
07 ST1300
Could be an air box thing? Pair valve thing? Got everything plugged back in proper?
I hear it shut up while revving then pop back on when idling down.
 
Joined
Jan 8, 2011
Messages
7,064
Location
Arizona
Bike
2007 Honda ST1300A
Sorry for the late reply, Lift the tank, and carefully remove the air box cover and see if you tilted or didn't seat your air filter correctly. I can hear the sound, and it sounds like the air filter is teetering back and forth sealing and not sealing.
When you lift the cover up slowly, peek in from the side before you lift it completely to see where it is sitting. It does sound like some kind of air leak. Also check the Pair hose connections, and the crank case breather hose on the front bottom of the air box base to make sure that both the hoses are connected and have not slipped off. (my guess would be the rear u-shaped hose that connects to the rear/bottom of the air box base plate.
Before you start ripping it all apart again, take a small mirror and see if you can see the rear hose attachment point.
When you put your TB hoses and 5 way tee back together (if you had them off) did you get any oil or anything on the fittings, allowing one of the hoses to pop back off?
Let us know what you find.
Igofar
 
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PFD023
Joined
Jan 15, 2014
Messages
182
Location
Canada
Yes indeed gentleman it was a hose which was not put on after I re-installed the lower section of the airbox. Front hose on the underside of the airbox was attached....not the rear one. It was the hose closest to the seat. Sounds perfect now. Thanks to all who took time to help a fellow ST member out.....truly a fantastic group of people in here.
Thanks again!
 
Joined
Jan 8, 2011
Messages
7,064
Location
Arizona
Bike
2007 Honda ST1300A
What a guess :run1: :rofl1:
Glad you got it sorted out without too much trouble.
Thanks for sharing what you found, as this may help other folks in the future.
Come here for the bikes - Stay for the People.
Mellow has the best forum ever!!! :plus1:
 
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