TBR7 Tune Up Stock Carb

Tomkay44 · 11-06-2021, 02:39 PM

I hacked the stock carb open and stuck the 110 jet in there. The air fuel mix screw was around 2.25 turns from the seat. I seated it and came 1.5 out on it. I DIDN'T PUT THE TWO SHIMS/WASHERS ON THE THROTTLE NEEDLE because I'm the opposite of a mechanic and didn't want to screw things up. Here are my 2 questions:

1) Since I didn't put the two shims/washers on, should I have left the air fuel mix screw where it was at 2.25 turns?
2) Is the double shim/washer thing an urgent essential thing

China Rider 27 · 11-06-2021, 04:52 PM

It is not critical or needed depending how your bike runs. Raising the needle (shimming it) helps with 1/4 to 3/4 throttle response. Raising the needle with shims richens (adds more gas) quicker under throttle. The air fuel mixture screw controls idle and affects to 1/4 throttle. The idle mixture screw should be adjusted from 1.5 turns for best idle.

Link to carb tuning:

https://www.motorcyclezombies.com/re...orcycle-carbs/

Tomkay44 · 11-06-2021, 08:31 PM

Thanks Chinarider 27
Would you happen to know the average or, general setting from factory for the air fuel mix screw?

China Rider 27 · 11-06-2021, 10:58 PM

Most of the carbs I have checked are at 1.25 to 1.5. as that is generally the default starting adjustment position.

krat · 11-07-2021, 12:46 PM

"Factory default setting" is only a position the factory uses to get the bike to run. It is not the perfect setting for 99% of the bikes on the road. It is just a start for tuning.

A guy in Denver, another in Chicago, and one in Atlanta are going to have very different jettings and screw settings.

buzz · 11-07-2021, 03:41 PM

shims need more gas and gp to a 115 jet . then mess with screw

11-06-2021, 02:39 PM	#1
Tomkay44 Join Date: Oct 2021 Location: Lumberton TX (Southeast TX) Posts: 110	TBR7 Tune Up Stock Carb I hacked the stock carb open and stuck the 110 jet in there. The air fuel mix screw was around 2.25 turns from the seat. I seated it and came 1.5 out on it. I DIDN'T PUT THE TWO SHIMS/WASHERS ON THE THROTTLE NEEDLE because I'm the opposite of a mechanic and didn't want to screw things up. Here are my 2 questions: 1) Since I didn't put the two shims/washers on, should I have left the air fuel mix screw where it was at 2.25 turns? 2) Is the double shim/washer thing an urgent essential thing
	0

11-07-2021, 12:46 PM	#5
krat Join Date: Nov 2019 Location: KY Posts: 260	"Factory default setting" is only a position the factory uses to get the bike to run. It is not the perfect setting for 99% of the bikes on the road. It is just a start for tuning. A guy in Denver, another in Chicago, and one in Atlanta are going to have very different jettings and screw settings. __________________ %90 of the Chinese motorbikes ever made are still on the road. The other %10 made it back home.
	0

11-06-2021, 04:52 PM	#2
China Rider 27 Join Date: Dec 2018 Location: PNW Posts: 982	It is not critical or needed depending how your bike runs. Raising the needle (shimming it) helps with 1/4 to 3/4 throttle response. Raising the needle with shims richens (adds more gas) quicker under throttle. The air fuel mixture screw controls idle and affects to 1/4 throttle. The idle mixture screw should be adjusted from 1.5 turns for best idle. Link to carb tuning: https://www.motorcyclezombies.com/re...orcycle-carbs/
	2

11-06-2021, 08:31 PM	#3
Tomkay44 Join Date: Oct 2021 Location: Lumberton TX (Southeast TX) Posts: 110	Thanks Chinarider 27 Would you happen to know the average or, general setting from factory for the air fuel mix screw?
	0

11-06-2021, 10:58 PM	#4
China Rider 27 Join Date: Dec 2018 Location: PNW Posts: 982	Most of the carbs I have checked are at 1.25 to 1.5. as that is generally the default starting adjustment position.
	1

11-07-2021, 03:41 PM	#6
buzz Join Date: Dec 2020 Location: Dayton Pa. Posts: 862	shims need more gas and gp to a 115 jet . then mess with screw
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