2017 Coolster 3125 CX-3 Carb Issues

Douglass · 03-04-2018, 10:26 AM

We ran the ATV for the first time yesterday. I started it, let it idle for about 10-15min, let it cool, then my son drove around the street for about 10 min. Then the ATV sounded like it was running out of gas, and stalled. Since then I have been constanly adjusting the idle to keep it from stalling. The other 2 issue I am having is when I give it full thottle the engine sounds like I just hit the kill switch. Sometimes at constant 1/2 throttle I am getting some surging.

The last think I noticed is it will some times make a pssst noise, and when it does this it will idle/run great, or I have to adjust the idle again.

Can you guys suggest a replacement carb for this unit? other than this the ATV seems like a decent unit.

david3921 · 03-04-2018, 04:17 PM

Search Amazon for a PZ20. Make sure that you get one that has screws or bolts on the bowl. You might have to change the jets. I paid a bit over $10 for mine and it was plug and play.

By the way, your photo shows that your gas is shut off.

Douglass · 03-04-2018, 06:10 PM

Quote:

I paid a bit over $10 for mine and it was plug and play.

By the way, your photo shows that your gas is shut off.

Here are the ones I am looking at. Thanks for the heads up, I turn it off when we are not running it.

https://www.amazon.com/dp/B008IK7TSA...v_ov_lig_dp_it

https://www.amazon.com/dp/B00FRVHO4M...v_ov_lig_dp_it

Both rate good, but one is more expensive. Are the both the same?

david3921 · 03-05-2018, 12:09 AM

I bought the first one. It says PZ20 on the page. The second one doesn't as far as I can tell.

Douglass · 03-05-2018, 02:46 PM

Cool, that is the one I ordered. I read a few reviews, and it sounds like the stock carb is just a poor quality unit even when the brass plug has been popped out allowing access to the mixture screw. One person said the stock carb had a plastic slide.

Douglass · 03-19-2018, 04:53 PM

I wanted to follow up now that I have had a chance to install, and adjust the carb.

I was having a couple issues with the stock carb. I am at sea level.

#1 inconstant idle, I was constantly having to adjust it

#2 I was getting some surging/bucking with light progressive acceleration

#3 The engine would bog down and die (unless I lifted the throttle) if I did a wide open pull from idle.

I pulled the bowl off, and could not tell what size jets installed by looking at them, but I did not remove them from the carburetor. The needle clip was in position # 4.

1st start was fast and easy, and was able to get the idle set to stay constant.
I had the throttle stop screw all the way in, and was a little rich off idle when acceleration.

Problem #2 was fixed, and problem #3 was not.

I installed the needle clip to position #3 (middle), and the light rich issue was gone, idle was great, problem #2 was gone, but still had problem # 3

I then installed the needle clip to position #5 (most rich), and problem #3 was fixed, but then I had very noticeable surging from idle with the with very light acceleration that I could not tune out with the air/fuel screw.

I ended up putting the needle clip in position #3 (middle) because the throttle stop screw is all the way in, and the engine runs/idles great. As my son's skills improve I'll change the clip position, and will try using different jets.

I am very happy with the purchase, and that it was such a cheap solution. I am however disappointed with Coolster with the way the engine ran with the stock part. I'm sure this would have been extremely frustrating for someone less mechanical. However, maybe this was done to pass the EPA/CA emissions.

03-05-2018, 12:09 AM	#4
david3921 Join Date: Feb 2009 Location: Michigan Posts: 1,031	I bought the first one. It says PZ20 on the page. The second one doesn't as far as I can tell. __________________ 2012 Kawasaki Versys 1984 Honda Magna V65 2016 Rhino 250 2016 Tao Tao 125D
	0

03-04-2018, 10:26 AM	#1
Douglass Join Date: Aug 2017 Location: Bay Area, CA Posts: 375	2017 Coolster 3125 CX-3 Carb Issues We ran the ATV for the first time yesterday. I started it, let it idle for about 10-15min, let it cool, then my son drove around the street for about 10 min. Then the ATV sounded like it was running out of gas, and stalled. Since then I have been constanly adjusting the idle to keep it from stalling. The other 2 issue I am having is when I give it full thottle the engine sounds like I just hit the kill switch. Sometimes at constant 1/2 throttle I am getting some surging. The last think I noticed is it will some times make a pssst noise, and when it does this it will idle/run great, or I have to adjust the idle again. Can you guys suggest a replacement carb for this unit? other than this the ATV seems like a decent unit.
	0

03-04-2018, 04:17 PM	#2
david3921 Join Date: Feb 2009 Location: Michigan Posts: 1,031	Search Amazon for a PZ20. Make sure that you get one that has screws or bolts on the bowl. You might have to change the jets. I paid a bit over $10 for mine and it was plug and play. By the way, your photo shows that your gas is shut off. __________________ 2012 Kawasaki Versys 1984 Honda Magna V65 2016 Rhino 250 2016 Tao Tao 125D
	0

03-05-2018, 02:46 PM	#5
Douglass Join Date: Aug 2017 Location: Bay Area, CA Posts: 375	Cool, that is the one I ordered. I read a few reviews, and it sounds like the stock carb is just a poor quality unit even when the brass plug has been popped out allowing access to the mixture screw. One person said the stock carb had a plastic slide.
	0

03-19-2018, 04:53 PM	#6
Douglass Join Date: Aug 2017 Location: Bay Area, CA Posts: 375	I wanted to follow up now that I have had a chance to install, and adjust the carb. I was having a couple issues with the stock carb. I am at sea level. #1 inconstant idle, I was constantly having to adjust it #2 I was getting some surging/bucking with light progressive acceleration #3 The engine would bog down and die (unless I lifted the throttle) if I did a wide open pull from idle. I pulled the bowl off, and could not tell what size jets installed by looking at them, but I did not remove them from the carburetor. The needle clip was in position # 4. 1st start was fast and easy, and was able to get the idle set to stay constant. I had the throttle stop screw all the way in, and was a little rich off idle when acceleration. Problem #2 was fixed, and problem #3 was not. I installed the needle clip to position #3 (middle), and the light rich issue was gone, idle was great, problem #2 was gone, but still had problem # 3 I then installed the needle clip to position #5 (most rich), and problem #3 was fixed, but then I had very noticeable surging from idle with the with very light acceleration that I could not tune out with the air/fuel screw. I ended up putting the needle clip in position #3 (middle) because the throttle stop screw is all the way in, and the engine runs/idles great. As my son's skills improve I'll change the clip position, and will try using different jets. I am very happy with the purchase, and that it was such a cheap solution. I am however disappointed with Coolster with the way the engine ran with the stock part. I'm sure this would have been extremely frustrating for someone less mechanical. However, maybe this was done to pass the EPA/CA emissions.
	0