Go Back   ChinaRiders Forums > Technical/Performance > Dual Sport/Enduro
Reply
 
Thread Tools Search this Thread Display Modes
Old 02-22-2017, 12:39 PM   #1
Sullybiker   Sullybiker is offline
 
Sullybiker's Avatar
 
Join Date: Dec 2016
Location: Western PA
Posts: 363
Anyone knows what this sound is - detonation?

You can hear it in the video as I apply throttle out of the corner: (advance the video to 12:50)
It sounds like a vibration / rattle. It's not hugely intrusive, but it's one of those things as a rider you notice. I thought it was the muffler end cap (it loosens as the muffler heats up, and vibrates) but I'm certain I only hear this noise under load.

My bike's done this from day one, irrespective of ambient temperature. I did think it was just the bike's character, but since looking into carb tuning and watching a lot of videos on the subject, I've wondered if it's spark knock / detonation. It happens in any gear, often in the same rpm range (hence it may be mechanical) I do run 87 octane (I usually don't bother with premium unless the manual specifies it) and will try a higher octane fuel next tank.

Bike runs great, very smooth, I'm just fearful of detonation if that's what it is.


 
Reply With Quote
Old 02-22-2017, 02:15 PM   #2
Ariel Red Hunter   Ariel Red Hunter is offline
 
Ariel Red Hunter's Avatar
 
Join Date: Jun 2016
Location: akwesasne, NY-13655
Posts: 2,220
Quote:
Originally Posted by Sullybiker View Post
You can hear it in the video as I apply throttle out of the corner: (advance the video to 12:50)
It sounds like a vibration / rattle. It's not hugely intrusive, but it's one of those things as a rider you notice. I thought it was the muffler end cap (it loosens as the muffler heats up, and vibrates) but I'm certain I only hear this noise under load.

My bike's done this from day one, irrespective of ambient temperature. I did think it was just the bike's character, but since looking into carb tuning and watching a lot of videos on the subject, I've wondered if it's spark knock / detonation. It happens in any gear, often in the same rpm range (hence it may be mechanical) I do run 87 octane (I usually don't bother with premium unless the manual specifies it) and will try a higher octane fuel next tank.

Bike runs great, very smooth, I'm just fearful of detonation if that's what it is.
It sounds like a sympathetic vibration of some component on the bike, to me. But yes, try a tank of 91 octane to see if it goes away......ARH


 
Reply With Quote
Old 02-22-2017, 02:17 PM   #3
JerryHawk250   JerryHawk250 is offline
Moderator
 
JerryHawk250's Avatar
 
Join Date: Oct 2016
Location: Houma, La.
Posts: 11,448
I know my Hawk requires 90 minimum.
__________________
2023 Venom Evader
2022 Lifan KPX250
2020 Kawasaki Vulcan S
2020 Venom Ghost 250
105main,40pilot,17/36 sprockets,NGK DPR8EIX-9
2016 Black Hawk 250
Keihin PE30 carb,125 main,38 slow.Pod filter,ported & decked head 10:1 CR,Direct Ignition Coil,15/40Sprockets,NGK DPR8EIX-9,De-Cat,Dual Oil Cooler,Digital Cluster
2016 Cazador180 XL
2014 Coolster150
JerryHawk250.com
My YouTube Channel


 
Reply With Quote
Old 02-22-2017, 03:44 PM   #4
2LZ   2LZ is offline
 
2LZ's Avatar
 
Join Date: Mar 2010
Location: Volcano, Ca
Posts: 7,033
Ours had a similar sound. I thought for sure it was either the air pump actuating under load or something in the motor. It only showed up sometimes, under certain rpm's and loads.
Ended up being the right side tank plastic wing that I discovered completely by accident.
The rear clip-on mount needed to be bent in a little to hold the wing tighter. Tap on both plastic wings toward the rear and see if you can replicate the noise.
__________________
"Light a fire for a man, and you heat him for a day. Light a man on fire, and you heat him for the rest of his life."

2007 Suzuki DRZ400S (SM convert)
2009 Q Link XP 200
1967 BSA B25 250cc Starfire
2022 Royal Enfield Interceptor 650
2023 Royal Enfield Scram 411
1948 Royal Enfield Model G 350


 
Reply With Quote
Old 02-22-2017, 05:05 PM   #5
jimwildman   jimwildman is offline
 
jimwildman's Avatar
 
Join Date: May 2016
Posts: 237
check the spark plug, look for black specs. ie salt and pepper.

detonation will remove particles of carbon from the plug, and even add specks of alluminum from the piston if its bad enough.


the bike sounds like its running decent. lean it would run like shit.. can you feel that in the performance of the bike?

detonation is often accomanied by a missfire that can be felt.


 
Reply With Quote
Old 02-22-2017, 05:26 PM   #6
mtiberio   mtiberio is offline
 
mtiberio's Avatar
 
Join Date: Jun 2016
Location: Arlington, VA
Posts: 258
Sounds normal to me. Pushrod motor, naturally sounds like a bag of bolts


 
Reply With Quote
Old 02-23-2017, 08:25 AM   #7
Sullybiker   Sullybiker is offline
 
Sullybiker's Avatar
 
Join Date: Dec 2016
Location: Western PA
Posts: 363
Thanks all. On the ride into work this morning I listened hard and I do think it's just engine 'character'.


 
Reply With Quote
Old 02-23-2017, 09:50 AM   #8
ughmas   ughmas is offline
 
ughmas's Avatar
 
Join Date: Feb 2016
Location: NY
Posts: 172
I had this exact noise occasionally when throttling on mine at first but it seems to have gone away, either on its own or from removing plastics/tightening fasteners etc throughout doing maintenance. I believe it was definitely more of a vibration coming from somewhere than a knock. Make sure all your plastics and motor mounts are snug
__________________
2005 CBR600RR
2016 CSC TT250 Coming Soon


 
Reply With Quote
Old 02-23-2017, 09:54 AM   #9
Ariel Red Hunter   Ariel Red Hunter is offline
 
Ariel Red Hunter's Avatar
 
Join Date: Jun 2016
Location: akwesasne, NY-13655
Posts: 2,220
Quote:
Originally Posted by mtiberio View Post
Sounds normal to me. Pushrod motor, naturally sounds like a bag of bolts
Oh, push rod buzz. I hadn't thought of that. Definitly a possibility. How's that for a definite answer!


 
Reply With Quote
Old 02-23-2017, 11:45 AM   #10
bogieboy   bogieboy is offline
 
bogieboy's Avatar
 
Join Date: May 2013
Location: finger lakes NY
Posts: 2,038
Quote:
Originally Posted by mtiberio View Post
Sounds normal to me. Pushrod motor, naturally sounds like a bag of bolts
bag of bolts? my pushrod cg200 sounds like a sewing machine....



 
Reply With Quote
Old 02-26-2017, 05:44 PM   #11
BARLOW   BARLOW is offline
 
BARLOW's Avatar
 
Join Date: Jan 2016
Location: central illinois
Posts: 362
i found mine to be the lock cover on the gas cap vibrating ... you should not need high octane fuel in a bike with such low compression though


 
Reply With Quote
Old 02-26-2017, 07:19 PM   #12
Sullybiker   Sullybiker is offline
 
Sullybiker's Avatar
 
Join Date: Dec 2016
Location: Western PA
Posts: 363
Quote:
Originally Posted by BARLOW View Post
you should not need high octane fuel in a bike with such low compression though
This was my thinking. The manual states 87, and I reckon the bikes are engineered to run on poor-quality fuel if necessary.


 
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 01:29 PM.


Powered by vBulletin® Version 3.8.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.