Hawk / TT250 Noise. Normal???

Sclark1013 · 08-08-2018, 08:56 PM

TT250 now has 350 miles. Runs great! Power and shifting has really improved. I have done 2 oil changes.
Two questions for y'all.. Keep in mind, I'm new to enduro's...

When letting off gas, engine makes pop, pop or backfire noise. Is this normal???

Also, when accelerating, I hear a knocking noise. Sounds kind of like a car pre-detonation / spark knock, but not quite as much rattle sound. I run ethanol free 88 octane gasoline or higher. I also add Lucas Fuel Injection treatment as CSC suggests. The chain is adjusted to spec. It's always done this and hasn't diminished or increased in loudness.

Do any of you experience this on your TT250 or Hawk? Because the bike runs so well, I'm beginning to think these are normal characteristics.

Really appreciate your feedback!

Weldangrind · 08-09-2018, 11:05 AM

Perhaps a Hawk owner will chime in about the knocking you're hearing.
The popping upon closing the throttle is a lean condition. I'd try a larger slow jet.

2LZ · 08-09-2018, 04:47 PM

Ours had a pesky knock. Then I found the plastic CSC license plate frame broke off and the knock quit. Not kidding..........

**JerryHawk250** · 08-09-2018, 05:02 PM

Real lean conditions will cause these symptoms. Also check for exhaust leaks. This will cause some back fire and may sound like knocking.

Sochin · 08-10-2018, 11:42 AM

Mine doesn't pop at all under ANY circumstance letting off the trottle. So richen up your slow jet a tad more. And if you hear ticking sound......that's normal from a pushrod engine and it is good.

bogieboy · 02-18-2019, 12:09 PM

try running a higher octane fuel, see if it goes away...

schleppy · 02-18-2019, 02:39 PM

Quote:

Originally Posted by bogieboy

try running a higher octane fuel, see if it goes away...

Shouldn't it run fine on 87? Maybe it's because it is winter time here, and the gas is pretty meh.

bogieboy · 02-18-2019, 02:57 PM

Quote:

Originally Posted by schleppy

Shouldn't it run fine on 87? Maybe it's because it is winter time here, and the gas is pretty meh.

in theory... i know my roketa very much likes 91 much better than 87... and if i can find 93 non ethanol, its worth 5mph on the top end...

schleppy · 02-18-2019, 02:58 PM

Quote:

Originally Posted by bogieboy

in theory... i know my roketa very much likes 91 much better than 87... and if i can find 93 non ethanol, its worth 5mph on the top end...

And you were getting audible knocking on 87?

41bigdawg · 02-18-2019, 05:25 PM

Pull your plug and read it...I would bet that you are lean. An air leak at the carb or exhaust will not help this either so check for that. My Hawk does not pop on decel or knock on accel running open exhaust and Mikuni clone. I also run 93 no ethanol fuel at all times.

41bigdawg · 02-18-2019, 05:54 PM

Holy Cow...that is very lean, what jets are you running?

schleppy · 02-18-2019, 05:59 PM

Quote:

Originally Posted by 41bigdawg

Holy Cow...that is very lean, what jets are you running?

No idea, I haven't completely removed the carb yet, just enough to do the needle lift. I'm guessing whatever the TT250 comes with stock. I'm at sea level, and it was 40 degrees outside tops, maybe the cold temps have made the already lean bike super lean?

41bigdawg · 02-18-2019, 06:10 PM

Not sure what the TT250 comes with stock but they are all very lean from the factory. Even with no mods you should bump the pilot and main up a little. You will be amazed how it runs when you give it some fuel

Will run a lot cooler too.

41bigdawg · 02-18-2019, 06:18 PM

I wouldn't think you have done any damage in 100 miles, especially in the cool temps. Get yourself a jet kit for it and then you can play around with it and get the fuel dialed in. Then you will be good to go.

schleppy · 02-18-2019, 06:19 PM

I'm going to chat with CSC tomorrow and order a few jets.

Quote:

Originally Posted by 41bigdawg

I wouldn't think you have done any damage in 100 miles, especially in the cool temps. Get yourself a jet kit for it and then you can play around with it and get the fuel dialed in. Then you will be good to go.

08-08-2018, 08:56 PM	#1
Sclark1013 Join Date: May 2018 Posts: 41	Hawk / TT250 Noise. Normal??? TT250 now has 350 miles. Runs great! Power and shifting has really improved. I have done 2 oil changes. Two questions for y'all.. Keep in mind, I'm new to enduro's... When letting off gas, engine makes pop, pop or backfire noise. Is this normal??? Also, when accelerating, I hear a knocking noise. Sounds kind of like a car pre-detonation / spark knock, but not quite as much rattle sound. I run ethanol free 88 octane gasoline or higher. I also add Lucas Fuel Injection treatment as CSC suggests. The chain is adjusted to spec. It's always done this and hasn't diminished or increased in loudness. Do any of you experience this on your TT250 or Hawk? Because the bike runs so well, I'm beginning to think these are normal characteristics. Really appreciate your feedback!
	0

08-09-2018, 11:05 AM	#2
Weldangrind Join Date: Mar 2009 Location: Sardis, BC, Canada Posts: 25,977	Perhaps a Hawk owner will chime in about the knocking you're hearing. The popping upon closing the throttle is a lean condition. I'd try a larger slow jet. __________________ Weldangrind "I figure I'm well-prepared for coping with a bike that comes from the factory with unresolved issues and that rewards the self-reliant owner." - Buccaneer
	2

08-09-2018, 04:47 PM	#3
2LZ Join Date: Mar 2010 Location: Volcano, Ca Posts: 7,092	Ours had a pesky knock. Then I found the plastic CSC license plate frame broke off and the knock quit. Not kidding.......... __________________ "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
	2

08-09-2018, 05:02 PM	#4
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,561	Real lean conditions will cause these symptoms. Also check for exhaust leaks. This will cause some back fire and may sound like knocking. __________________ 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S 2004 Honda ST 1300 2016 Black Hawk 250 (sold) 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
	2

08-10-2018, 11:42 AM	#5
Sochin Join Date: Jul 2017 Location: Montucky Posts: 209	Mine doesn't pop at all under ANY circumstance letting off the trottle. So richen up your slow jet a tad more. And if you hear ticking sound......that's normal from a pushrod engine and it is good. __________________ 1991 Kawasaki KLR250
	2

02-18-2019, 12:09 PM	#6
bogieboy Join Date: May 2013 Location: finger lakes NY Posts: 2,045	try running a higher octane fuel, see if it goes away...
	0

02-18-2019, 05:25 PM	#10
41bigdawg Join Date: Sep 2018 Location: Tennessee Posts: 41	Pull your plug and read it...I would bet that you are lean. An air leak at the carb or exhaust will not help this either so check for that. My Hawk does not pop on decel or knock on accel running open exhaust and Mikuni clone. I also run 93 no ethanol fuel at all times.
	0

02-18-2019, 05:54 PM	#11
41bigdawg Join Date: Sep 2018 Location: Tennessee Posts: 41	Holy Cow...that is very lean, what jets are you running?
	0

02-18-2019, 06:10 PM	#13
41bigdawg Join Date: Sep 2018 Location: Tennessee Posts: 41	Not sure what the TT250 comes with stock but they are all very lean from the factory. Even with no mods you should bump the pilot and main up a little. You will be amazed how it runs when you give it some fuel Will run a lot cooler too.
	0

02-18-2019, 06:18 PM	#14
41bigdawg Join Date: Sep 2018 Location: Tennessee Posts: 41	I wouldn't think you have done any damage in 100 miles, especially in the cool temps. Get yourself a jet kit for it and then you can play around with it and get the fuel dialed in. Then you will be good to go.
	0