2022 KPR 200 Idle and Throttle Issue

nickelghandi · 09-25-2022, 05:43 PM

Hi all,
I am new to the forum. I have a 2022 Lifan KPR 200 that I just got. It starts fine and will usually idle, but it hunts in RPMs and occasionally stalls. It doesn't seem to matter if it's hot or cold outside or if the bike is warm or not.

If the bike is at idle and in neutral or has the clutch in and I twist the throttle a bit, the bike dies. I have to very gingerly turn the throttle and get the RPMs up to about 2-2.5K before it will properly rev. I am currently working with the seller but progress is very slow. If anyone has any clue what the issue could be, please post or shoot me a PM. Video is below.

It's fixed! Check the new video for the procedure:

herbie · 09-26-2022, 08:17 AM

I would check the intake to make sure everything is tight. But I would do the basics first, check valve clearance and check spark plug gap or replace the plug to make sure the engine is able to run good. If it’s still having a problem after that at least you know that part is good.

JimS · 09-26-2022, 02:10 PM

Also check all of the electrical connections on the engine to make sure they are fully seated and there are no bent pins. Being ECU controlled, a bad or missing input from any one of the sensors could cause issues that may or may not trigger the check engine light.

Is your radiator full of coolant?

nickelghandi · 09-26-2022, 05:05 PM

Thanks for the suggestions guys. Last night I pulled off the right panel and checked over the intake and EFI parts again. Then I tried unplugging things one by one and starting the bike. Unplugging the sensor pictured here seems to improve the running of the bike tremendously. It idles smoother and I can turn it to 1/3 throttle from idle without it dying.

My guess would be that it is the MAP sensor? It connects to a short hose that connects directly to the intake manifold. The only other connection to it is the electrical connection.

JimS · 09-26-2022, 06:36 PM

That sensor should be bolted to the left side of the intake manifold. In the photos you posted, it appears to be on top.

I've attached a photo of the mounting location.

JimS · 09-26-2022, 06:45 PM

https://cdn.shopify.com/s/files/1/02...f?v=1636701098

The link above should show the EFI system layout on page 94. The Intake Pressure Sensor is the part in question I believe.

nickelghandi · 09-27-2022, 10:53 AM

Quote:

Originally Posted by JimS

Join Date: Jul 2022
Location: New Mexico
Posts: 41
That sensor should be bolted to the left side of the intake manifold. In the photos you posted, it appears to be on top.

https://cdn.shopify.com/s/files/1/02...f?v=1636701098

The link above should show the EFI system layout on page 94. The Intake Pressure Sensor is the part in question I believe.

You are correct. I pulled the sensor to get a better photo of it. You are also correct about which sensor it is, however that wasn’t the issue. The seller recommended checking the idle gulp valve screw and adjusting counterclockwise in 1/4 turn increments and then testing after each adjustment. That was the issue. I had to go almost 1 1/2 turns counterclockwise but the bike runs and revs great now even from a cold start. It’s likely that unplugging the pressure sensor was preventing the EFI system from tuning the mix and let the bike run a bit better misleading me. I’ll make a video on it because I have some fine tuning to do still but here is a photo of the adjustment screw. It’s best to remove the canister from its mounts to make it easier to get a screwdriver on the screw.

JimS · 09-27-2022, 01:05 PM

Glad you got it figured out! Happy riding!

nickelghandi · 09-27-2022, 02:12 PM

Me too! Thanks for the help!

KPM · 09-29-2022, 12:45 PM

Glad you got it figured out.

I'm sure a lot of others learned something new about that engine, like W T H is a gulp valve. Even the manual linked above doesn't talk about it, only mentions the screw's location 1x, but doesn't explain its function.

For those interested how a gulp valve works....
https://mossmotoring.com/gulp-valve-...fire-solution/

Now we know how to get these bikes to backfire if we want to.

nickelghandi · 12-12-2022, 01:05 PM

I have fixed it, folks! Video is in the OP and below:

09-25-2022, 05:43 PM	#1
nickelghandi Join Date: Sep 2022 Location: Kentucky Posts: 10	2022 KPR 200 Idle and Throttle Issue Hi all, I am new to the forum. I have a 2022 Lifan KPR 200 that I just got. It starts fine and will usually idle, but it hunts in RPMs and occasionally stalls. It doesn't seem to matter if it's hot or cold outside or if the bike is warm or not. If the bike is at idle and in neutral or has the clutch in and I twist the throttle a bit, the bike dies. I have to very gingerly turn the throttle and get the RPMs up to about 2-2.5K before it will properly rev. I am currently working with the seller but progress is very slow. If anyone has any clue what the issue could be, please post or shoot me a PM. Video is below. It's fixed! Check the new video for the procedure: Last edited by nickelghandi; 12-12-2022 at 01:04 PM.
	0

09-26-2022, 08:17 AM	#2
herbie Join Date: May 2019 Location: Illinois Posts: 867	I would check the intake to make sure everything is tight. But I would do the basics first, check valve clearance and check spark plug gap or replace the plug to make sure the engine is able to run good. If it’s still having a problem after that at least you know that part is good. __________________ 2022 Venom KPR 200 Red- the fastest color 16t and 46t sprockets, NGK Iridium CPR8EAIX-9, aftermarket full exhaust system. Top speed 81GPS 2023 Venom SS3 KP mini 150– Nibbi carb, Nibbi air filter, aftermarket muffler, decat 2022 Venom Ghost chopper 250 1997 Honda GL1500 Goldwing 1978 Kawasaki KL250 https://youtube.com/@herbiesgarage681
	2

09-27-2022, 02:12 PM	#9
nickelghandi Join Date: Sep 2022 Location: Kentucky Posts: 10	Me too! Thanks for the help! __________________ - Nick 2022 BD125-10 XPRO Vader - ZS 190 Swap - 17T Front Sprocket - Nibbi 48MM Intake Pod Filter - Nibbi Clutch and Throttle cables 2022 Lifan KPR200 Stock... for now. My YouTube Channel
	1

12-12-2022, 01:05 PM	#11
nickelghandi Join Date: Sep 2022 Location: Kentucky Posts: 10	I have fixed it, folks! Video is in the OP and below: __________________ - Nick 2022 BD125-10 XPRO Vader - ZS 190 Swap - 17T Front Sprocket - Nibbi 48MM Intake Pod Filter - Nibbi Clutch and Throttle cables 2022 Lifan KPR200 Stock... for now. My YouTube Channel
	2

09-26-2022, 02:10 PM	#3
JimS Join Date: Jul 2022 Location: New Mexico Posts: 81	Also check all of the electrical connections on the engine to make sure they are fully seated and there are no bent pins. Being ECU controlled, a bad or missing input from any one of the sensors could cause issues that may or may not trigger the check engine light. Is your radiator full of coolant?
	2

09-26-2022, 06:45 PM	#6
JimS Join Date: Jul 2022 Location: New Mexico Posts: 81	https://cdn.shopify.com/s/files/1/02...f?v=1636701098 The link above should show the EFI system layout on page 94. The Intake Pressure Sensor is the part in question I believe.
	1

09-27-2022, 01:05 PM	#8
JimS Join Date: Jul 2022 Location: New Mexico Posts: 81	Glad you got it figured out! Happy riding!
	1

09-29-2022, 12:45 PM	#10
KPM Join Date: Jun 2022 Posts: 21	Glad you got it figured out. I'm sure a lot of others learned something new about that engine, like W T H is a gulp valve. Even the manual linked above doesn't talk about it, only mentions the screw's location 1x, but doesn't explain its function. For those interested how a gulp valve works.... https://mossmotoring.com/gulp-valve-...fire-solution/ Now we know how to get these bikes to backfire if we want to.
	0