New tt250 help

Bobertj · 06-06-2019, 10:10 AM

So bought new tt250 nice bike but having one issue basically when you try to give it 1/2 throttle or more the bike misses as it climbs through the rpm range if you feather it all the way through no missing only half throttle
Or more csc has been helpful sent me coil and new computer for the coil still same problem my
First thought was fuel and I’m still leaning towards this being
The issue any ideas? New to the forum thank you so
Much

NzBrakelathes · 06-06-2019, 10:23 AM

Have you checked valves? This might help a little
Second thing is tune the carb or look into carb check jetting that’s actually in it
I do have a set listed in my eBay store for first tune, this might be useful to you.
So you changed the CDI and coil? Any color smoke when it plays up?

NzBrakelathes · 06-06-2019, 10:25 AM

Do you have a timing light? See if it’s loosing spark when it plays up etc

**JerryHawk250** · 06-06-2019, 10:31 AM

Also try a new plug. The one that came on the bike may be defective or cracked. I agree, valve lash would be one of the first things to check.

Bobertj · 06-06-2019, 10:35 AM

Thank you both for response so the valves are due in the next 40 miles so I’ll be doing them this weekend yes replaced both under warranty and also spark plug was the first thing I did to see and no improvement with all three those parts replaced. Changed the oil already bike is about to hit 500

Bobertj · 06-06-2019, 10:36 AM

Also idk what size jets are in it that’s was my thought maybe needs a different main
Jet since it’s only 1/2 throttle or more
I’m not to well with carbs but I’m
Decent with cars etc so

**JerryHawk250** · 06-06-2019, 10:47 AM

Try adjusting the idle mixture. It may be set to lean. Once you have the idle mixture set and it still does it then you can raise the needle up one notch.

NzBrakelathes · 06-06-2019, 10:48 AM

Quote:

Originally Posted by Bobertj

Also idk what size jets are in it that’s was my thought maybe needs a different main
Jet since it’s only 1/2 throttle or more
I’m not to well with carbs but I’m
Decent with cars etc so

DO check my eBay store for some stuff that might help you etc
Valve adj set, first tune set, carb air screw adjuster all could be useful to you
I’m in the USA Saturday and have some products with me or it be 2ish weeks before I’m back
If you’re lucky I might be passing thru your area if you’re west coast lol
I have some items to drop off to customers already and it’s not the first time I’ve deluverrd in person

Bobertj · 06-06-2019, 10:52 AM

Ok I’ll check it out. Do I have to take the carb off to change the idle mixture ? Think the older models don’t have screw but I believe mine does

Ariel Red Hunter · 06-06-2019, 11:05 AM

Quote:

Originally Posted by Bobertj

So bought new tt250 nice bike but having one issue basically when you try to give it 1/2 throttle or more the bike misses as it climbs through the rpm range if you feather it all the way through no missing only half throttle
Or more csc has been helpful sent me coil and new computer for the coil still same problem my
First thought was fuel and I’m still leaning towards this being
The issue any ideas? New to the forum thank you so
Much

My first thought is "too lean."...ARH

Bobertj · 06-06-2019, 11:14 AM

Ok yea I agree that’s its probably to lean do I need to take the carb apart to fix that ? And if so do
I just move the needle or change the jets thank you all for the responses just trying figure out the best way to go about it when I take the bike apart

**JerryHawk250** · 06-06-2019, 11:16 AM

Quote:

Originally Posted by Bobertj

Ok I’ll check it out. Do I have to take the carb off to change the idle mixture ? Think the older models don’t have screw but I believe mine does

The stock carb does have an idle mixture screw. It may be covered by with a plastic or brass cap that can be drilled out. It will be hard to adjust while on the bike but can be done. You want to adjust the idle mixture after the engines up to running temperature.

Air_male · 06-06-2019, 12:00 PM

and please make sure the choke is off

Megadan · 06-06-2019, 01:08 PM

I actually agree with the choke comment. Make sure the choke is all the way off (open). If you only have it in the half choke position it will behave almost exactly as you describe.

Azhule · 06-06-2019, 01:42 PM

This might also be helpful if you have to actually open up the CSC carb for cleaning or needle adjustments

https://www.cscmotorcycles.com/check...or-maintenance

06-06-2019, 10:10 AM	#1
Bobertj Join Date: Jun 2019 Posts: 12	New tt250 help So bought new tt250 nice bike but having one issue basically when you try to give it 1/2 throttle or more the bike misses as it climbs through the rpm range if you feather it all the way through no missing only half throttle Or more csc has been helpful sent me coil and new computer for the coil still same problem my First thought was fuel and I’m still leaning towards this being The issue any ideas? New to the forum thank you so Much
	0

06-06-2019, 10:31 AM	#4
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,593	Also try a new plug. The one that came on the bike may be defective or cracked. I agree, valve lash would be one of the first things to check. __________________ 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S (Sold) 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
	0

06-06-2019, 10:47 AM	#7
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,593	Try adjusting the idle mixture. It may be set to lean. Once you have the idle mixture set and it still does it then you can raise the needle up one notch. __________________ 2023 Lifan Lycan 250 Chopper 2023 Venom Evader 2022 Lifan KPX250 2020 Kawasaki Vulcan S (Sold) 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 Last edited by JerryHawk250; 06-07-2019 at 07:52 AM.
	0

06-06-2019, 01:08 PM	#14
Megadan Join Date: Apr 2017 Location: Omaha, NE Posts: 8,065	I actually agree with the choke comment. Make sure the choke is all the way off (open). If you only have it in the half choke position it will behave almost exactly as you describe. __________________ Hawk Information and Resource guide: http://www.chinariders.net/showthread.php?t=20331 2018 Hawk 250 - Full Mod list here. http://www.chinariders.net/showpost....62&postcount=1 2024 Royal Enfield Shotgun 650 https://chinariders.net/showthread.php?t=34124
	1

06-06-2019, 01:42 PM	#15
Azhule Join Date: Dec 2015 Location: CO Posts: 1,525	This might also be helpful if you have to actually open up the CSC carb for cleaning or needle adjustments https://www.cscmotorcycles.com/check...or-maintenance __________________ "Think as you like... but this self proclaimed Professor is always right" - Buckshot "You never know what someone is hiding beneath their smile..." - NinjaTom - R.I.P.
	3

06-06-2019, 10:23 AM	#2
NzBrakelathes Join Date: Jun 2016 Location: Hell Posts: 2,408	Have you checked valves? This might help a little Second thing is tune the carb or look into carb check jetting that’s actually in it I do have a set listed in my eBay store for first tune, this might be useful to you. So you changed the CDI and coil? Any color smoke when it plays up?
	0

06-06-2019, 10:25 AM	#3
NzBrakelathes Join Date: Jun 2016 Location: Hell Posts: 2,408	Do you have a timing light? See if it’s loosing spark when it plays up etc
	0

06-06-2019, 10:35 AM	#5
Bobertj Join Date: Jun 2019 Posts: 12	Thank you both for response so the valves are due in the next 40 miles so I’ll be doing them this weekend yes replaced both under warranty and also spark plug was the first thing I did to see and no improvement with all three those parts replaced. Changed the oil already bike is about to hit 500
	0

06-06-2019, 10:36 AM	#6
Bobertj Join Date: Jun 2019 Posts: 12	Also idk what size jets are in it that’s was my thought maybe needs a different main Jet since it’s only 1/2 throttle or more I’m not to well with carbs but I’m Decent with cars etc so
	0

06-06-2019, 10:52 AM	#9
Bobertj Join Date: Jun 2019 Posts: 12	Ok I’ll check it out. Do I have to take the carb off to change the idle mixture ? Think the older models don’t have screw but I believe mine does
	0

06-06-2019, 11:14 AM	#11
Bobertj Join Date: Jun 2019 Posts: 12	Ok yea I agree that’s its probably to lean do I need to take the carb apart to fix that ? And if so do I just move the needle or change the jets thank you all for the responses just trying figure out the best way to go about it when I take the bike apart
	0

06-06-2019, 12:00 PM	#13
Air_male Join Date: Mar 2019 Posts: 24	and please make sure the choke is off
	1