Carb adjusting

Al · 05-13-2018, 01:14 PM

Hello all

I recently placed a new carb on my 125. I believe it was a pz20. I am having two issues.

1. The atv will only start if I pull the choke in and out quickly while cranking.

2. I am constantly adjusting the carb idle and air fuel. I have followed the instructions posted here about adjusting air fuel and idle, still no luck.

Any help is appreciated as my children lose interest when things don't work.
Thanks

Douglass · 05-13-2018, 04:56 PM

Could you post a picture of what carb you have? Have you changed the spark plug?

How do you have the air screw set, and what position is the needle clip in?

Al · 05-13-2018, 05:55 PM

It is a pz20. I have changed the plug and it does have the air fuel mixture screw. The clip is in the middle setting. I think 3 of 5.

Thanks

Douglass · 05-14-2018, 01:16 PM

First verify the choke is operating correctly. Physically check to make sure it is opening and closing. If it is working correctly, then This is how I would start with a new Carb in your situation. Screw the air fuel screw in until it just starts to get firm. Back it out 1 1/2 turns. Drop the clip on the needle (1) position. Turn the idle screw in 1/4 to 1/2 turn, and verify the spark plug is not fouled.

This should be a pretty good starting point, you could also pull the spark plug to verify spark. Pull the plug, ground it to the engine block, hit the start button/kickstart to verify you have a good consistent spark. Make sure the fuel is turned off while checking this.

What was the reason for replacing the carburetor?

Doulgass

Al · 05-14-2018, 03:08 PM

I read some where that a pz19 is better than the pz20. I have order one and install it when it arrives. Thanks for your help on adjusting, I will do that this weekend. The choke is working and the spark is also there. My issue is really starting and constantly adjusting the idle airfield. Thanks any more ideas are always welcome.

This is a great community!!

FLASHLIGHTBOY · 05-15-2018, 10:49 PM

try looking at the gasket for the carb... orings.... it will suck air in there,,,,, if it runs with the choke on... then die when you take it off.. then that is wrong

Al · 05-16-2018, 04:39 AM

Runs with the choke on. It's just the starting and having to reset the idle everytime after I turn the atv off and let it cool.

Al · 06-22-2018, 02:08 PM

I changed all the fuel lines and now the atv starts instantly. Runs a little high in the rpm. When I adjust the idle screw the idle does not change. Also when I open the air/fuel screw rpm does not change. Both screws are totally out. My question is if both screws are tight and the atv run fine, do I have a perfect adjustment? Does the choke clip position affect the idle?

**JerryHawk250** · 06-22-2018, 02:12 PM

Check to make sure you have a little slack in the throttle cable so that it can return to the closed position. If there is no slack in the cable it may be holding the throttle slightly open.

05-13-2018, 01:14 PM	#1
Al Join Date: Jun 2017 Posts: 73	Carb adjusting Hello all I recently placed a new carb on my 125. I believe it was a pz20. I am having two issues. 1. The atv will only start if I pull the choke in and out quickly while cranking. 2. I am constantly adjusting the carb idle and air fuel. I have followed the instructions posted here about adjusting air fuel and idle, still no luck. Any help is appreciated as my children lose interest when things don't work. Thanks
	0

05-15-2018, 10:49 PM	#6
FLASHLIGHTBOY Join Date: May 2009 Location: SASKATOON Posts: 1,161	carb try looking at the gasket for the carb... orings.... it will suck air in there,,,,, if it runs with the choke on... then die when you take it off.. then that is wrong __________________ DEALER FOR ZSTAR & GIO PRODUCTS, TAOTAO ABIBABA ATV ETC
	0

06-22-2018, 02:12 PM	#9
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,562	Check to make sure you have a little slack in the throttle cable so that it can return to the closed position. If there is no slack in the cable it may be holding the throttle slightly open. __________________ 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
	1

05-13-2018, 04:56 PM	#2
Douglass Join Date: Aug 2017 Location: Bay Area, CA Posts: 375	Could you post a picture of what carb you have? Have you changed the spark plug? How do you have the air screw set, and what position is the needle clip in?
	0

05-13-2018, 05:55 PM	#3
Al Join Date: Jun 2017 Posts: 73	It is a pz20. I have changed the plug and it does have the air fuel mixture screw. The clip is in the middle setting. I think 3 of 5. Thanks
	0

05-14-2018, 01:16 PM	#4
Douglass Join Date: Aug 2017 Location: Bay Area, CA Posts: 375	First verify the choke is operating correctly. Physically check to make sure it is opening and closing. If it is working correctly, then This is how I would start with a new Carb in your situation. Screw the air fuel screw in until it just starts to get firm. Back it out 1 1/2 turns. Drop the clip on the needle (1) position. Turn the idle screw in 1/4 to 1/2 turn, and verify the spark plug is not fouled. This should be a pretty good starting point, you could also pull the spark plug to verify spark. Pull the plug, ground it to the engine block, hit the start button/kickstart to verify you have a good consistent spark. Make sure the fuel is turned off while checking this. What was the reason for replacing the carburetor? Doulgass
	0

05-14-2018, 03:08 PM	#5
Al Join Date: Jun 2017 Posts: 73	I read some where that a pz19 is better than the pz20. I have order one and install it when it arrives. Thanks for your help on adjusting, I will do that this weekend. The choke is working and the spark is also there. My issue is really starting and constantly adjusting the idle airfield. Thanks any more ideas are always welcome. This is a great community!!
	0

05-16-2018, 04:39 AM	#7
Al Join Date: Jun 2017 Posts: 73	Runs with the choke on. It's just the starting and having to reset the idle everytime after I turn the atv off and let it cool.
	0

06-22-2018, 02:08 PM	#8
Al Join Date: Jun 2017 Posts: 73	I changed all the fuel lines and now the atv starts instantly. Runs a little high in the rpm. When I adjust the idle screw the idle does not change. Also when I open the air/fuel screw rpm does not change. Both screws are totally out. My question is if both screws are tight and the atv run fine, do I have a perfect adjustment? Does the choke clip position affect the idle?
	0