Vader stalls when pushed

4T_Goblin · 11-11-2021, 07:43 AM

https://youtube.com/shorts/gr_BFBy-CtE?feature=share

I'm currently trying to tune a mikuni vm22 round slide.
Recently I botched an oil change by putting too much oil in. I have since corrected the amount of oil to 800ml.

That being said- I have changed the pilot to 15 from 35, kept the main jet at 100, adjusted the float bowl to ~21mm. I'm running a Venom Motorsports exhaust and Polini foam filter.

My main problem is I find it hard to tune the bike by riding it when it is able to stall out with a little push forward or backward. This weekend I'll time to get out on the street and investigate issues and see how it rides.

Has anyone had this problem? Could my engine be flooded? Seems like there's liquid pooling somewhere (other than float bowl) and sloshing when pushed.

Thanks all

krat · 11-11-2021, 10:13 PM

Why did you change the piolet to 15? All of these bikes need 30-40 idle jets!

You are simply starving it to death. the slightest shake stalls it. I am shocked that you can get it to start! The idle speed is also way too low. Go back to the 30 and turn the Air/fuel screw out about 2 turns and go from there.

The way we have to "tune" these carbs is a joke. Due to the placement of the adjustment screw you can not dial in fastest idle with the A/F screw, then dial in the throttle screw to proper setting like a normal carb.

The gas you hear "sloshing" is inside your half empty fuel tank. That is the only place where there is enough gas to "slosh" anywhere on that bike! It goes tank, fuel line, carb, engine with no detours to a puddle or container anywhere between.

4T_Goblin · 11-12-2021, 05:38 AM

I changed the pilot because the bike was running rich. Black spark plugs. The pilot was 35*. I went down to 15. It's idling basically the same.
I had the AF turned 2 turns out, same deal.
I read some reviews and comments describing the extra richness of the 30 pilot so I tried a smaller pilot. That is all.

It stalled with 35 pilot, it's stalling with 15 pilot.

I know what gas in the gas tank sounds like. I didn't say I heard the sloshing of gas. I said I think there's pooling happening somewhere, dumping on the plug? but I can't be sure, I do not know.

Still looking for answers or places to check.

Thanks all

**JerryHawk250** · 11-12-2021, 06:31 AM

Check that your float is not set too high.

4T_Goblin · 11-12-2021, 07:36 AM

It was stock set at ~26mm, I set it to 21mm. Had the issue both times. I can try going higher to 30mm

TominMO · 11-12-2021, 08:45 AM

Reset everything back to stock.
Watch a few motorcycle carb jetting vids on Youtube.
Get a range of pilot and main jets, both larger and smaller, and experiment from there.
Go up or down one increment at a time. Dropping from 35 to 15 is drastic; not the way to tune properly.
If anything, you could assume as a starting point that the bike is jetted lean from the factory, due to having to meet emissions standards.

david3921 · 11-12-2021, 09:24 AM

Quote:

Originally Posted by 4T_Goblin

It was stock set at ~26mm, I set it to 21mm. Had the issue both times. I can try going higher to 30mm

From a post from Weldangrind:

"I would set the float level with the carb upside down and no pressure on the floats (other than gravity). The plastic parting line in the middle of the float should be parallel to the gasket surface.

I've had good luck setting them with this process. Thanks again Weldangrind wherever you are!

Thread with above quote. Lots of good carb info;

http://chinariders.net/showthread.ph...ng+float+level

4T_Goblin · 11-12-2021, 10:11 AM

If the carb was jetted lean, then wouldn't I get a lean looking plug from a chop? All my plugs are coming out black.
The bike stalled with 35 pilot, and with 15 pilot. It stalled with 26mm float height, and 21mm float height.
That's why I'm thinking there's something else happening. When I did the oil change first, I put too much in, lots of white smoke. The oil wasn't looking that good either, like gas was getting in.
Still I'm going back and checking everything I can this weekend

**JerryHawk250** · 11-12-2021, 10:25 AM

If your oil smells like it has gas in it then the float valve is probably leaking which would explain it running rich at idle.

J4Fun · 11-12-2021, 10:32 AM

And you sloshing noise is caused by thin oil do too gas in the crankcase.

4T_Goblin · 11-12-2021, 10:51 AM

I want to note that I adjusted the float bowl with mikuni manual and spec, 21mm. Mikuni recommend laying carb on the side.

China Rider 27 · 11-12-2021, 11:14 AM

Definitely sounds fuel delivery. Check see if something is holding float open little. take hose attached to fuel intake and blow air into it while closing the float to see if it seals. Remove the needle seat see if something preventing needle seating. I would clean out all carburetor passages with spray cleaner and air if I could.

4T_Goblin · 11-12-2021, 11:38 AM

The stalling you think sounds like fuel delivery?

China Rider 27 · 11-12-2021, 12:14 PM

Carburetor related as you describe getting too much fuel. I would clean it good and check operation float as above. Watch out with the carb cleaner though on your bowl gasket it can cause rubber to swell and create issues. That is a genuine Mikuni VM22?

Falkon45 · 11-12-2021, 01:05 PM

check your coil, spark plug wire, and any electrical plug that is connected to ignition. I have a feeling something electrical is loose, and it's not your carb.

11-11-2021, 07:43 AM	#1
4T_Goblin Join Date: Jun 2021 Posts: 239	Vader stalls when pushed https://youtube.com/shorts/gr_BFBy-CtE?feature=share I'm currently trying to tune a mikuni vm22 round slide. Recently I botched an oil change by putting too much oil in. I have since corrected the amount of oil to 800ml. That being said- I have changed the pilot to 15 from 35, kept the main jet at 100, adjusted the float bowl to ~21mm. I'm running a Venom Motorsports exhaust and Polini foam filter. My main problem is I find it hard to tune the bike by riding it when it is able to stall out with a little push forward or backward. This weekend I'll time to get out on the street and investigate issues and see how it rides. Has anyone had this problem? Could my engine be flooded? Seems like there's liquid pooling somewhere (other than float bowl) and sloshing when pushed. Thanks all
	0

11-11-2021, 10:13 PM	#2
krat Join Date: Nov 2019 Location: KY Posts: 257	Why did you change the piolet to 15? All of these bikes need 30-40 idle jets! You are simply starving it to death. the slightest shake stalls it. I am shocked that you can get it to start! The idle speed is also way too low. Go back to the 30 and turn the Air/fuel screw out about 2 turns and go from there. The way we have to "tune" these carbs is a joke. Due to the placement of the adjustment screw you can not dial in fastest idle with the A/F screw, then dial in the throttle screw to proper setting like a normal carb. The gas you hear "sloshing" is inside your half empty fuel tank. That is the only place where there is enough gas to "slosh" anywhere on that bike! It goes tank, fuel line, carb, engine with no detours to a puddle or container anywhere between. __________________ %90 of the Chinese motorbikes ever made are still on the road. The other %10 made it back home.
	1

11-12-2021, 06:31 AM	#4
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,553	Check that your float is not set too high. __________________ 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
	2

11-12-2021, 08:45 AM	#6
TominMO Join Date: Sep 2021 Location: De Soto, MO Posts: 1,868	Reset everything back to stock. Watch a few motorcycle carb jetting vids on Youtube. Get a range of pilot and main jets, both larger and smaller, and experiment from there. Go up or down one increment at a time. Dropping from 35 to 15 is drastic; not the way to tune properly. If anything, you could assume as a starting point that the bike is jetted lean from the factory, due to having to meet emissions standards. __________________ 2021 Lifan Xpect--sold 2022 Lifan KPX 1972 Honda CT90--The Carrot 1969 Honda CT90--The Tomahto Cheesy is the WDK (workplace drama king). Now retired. Nope, back in the saddle. Climate: The Movie https://www.youtube.com/watch?v=A24fWmNA6lM How our government really works https://www.youtube.com/watch?v=QjadCd0VRBw Question all authority.....think for yourself
	1

11-12-2021, 10:25 AM	#9
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,553	If your oil smells like it has gas in it then the float valve is probably leaking which would explain it running rich at idle. __________________ 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
	2

11-12-2021, 05:38 AM	#3
4T_Goblin Join Date: Jun 2021 Posts: 239	I changed the pilot because the bike was running rich. Black spark plugs. The pilot was 35*. I went down to 15. It's idling basically the same. I had the AF turned 2 turns out, same deal. I read some reviews and comments describing the extra richness of the 30 pilot so I tried a smaller pilot. That is all. It stalled with 35 pilot, it's stalling with 15 pilot. I know what gas in the gas tank sounds like. I didn't say I heard the sloshing of gas. I said I think there's pooling happening somewhere, dumping on the plug? but I can't be sure, I do not know. Still looking for answers or places to check. Thanks all
	0

11-12-2021, 07:36 AM	#5
4T_Goblin Join Date: Jun 2021 Posts: 239	It was stock set at ~26mm, I set it to 21mm. Had the issue both times. I can try going higher to 30mm
	0

11-12-2021, 10:11 AM	#8
4T_Goblin Join Date: Jun 2021 Posts: 239	If the carb was jetted lean, then wouldn't I get a lean looking plug from a chop? All my plugs are coming out black. The bike stalled with 35 pilot, and with 15 pilot. It stalled with 26mm float height, and 21mm float height. That's why I'm thinking there's something else happening. When I did the oil change first, I put too much in, lots of white smoke. The oil wasn't looking that good either, like gas was getting in. Still I'm going back and checking everything I can this weekend
	0

11-12-2021, 10:32 AM	#10
J4Fun Join Date: May 2021 Posts: 271	And you sloshing noise is caused by thin oil do too gas in the crankcase.
	1

11-12-2021, 10:51 AM	#11
4T_Goblin Join Date: Jun 2021 Posts: 239	I want to note that I adjusted the float bowl with mikuni manual and spec, 21mm. Mikuni recommend laying carb on the side.
	0

11-12-2021, 11:14 AM	#12
China Rider 27 Join Date: Dec 2018 Location: PNW Posts: 982	Definitely sounds fuel delivery. Check see if something is holding float open little. take hose attached to fuel intake and blow air into it while closing the float to see if it seals. Remove the needle seat see if something preventing needle seating. I would clean out all carburetor passages with spray cleaner and air if I could.
	1

11-12-2021, 11:38 AM	#13
4T_Goblin Join Date: Jun 2021 Posts: 239	The stalling you think sounds like fuel delivery?
	0

11-12-2021, 12:14 PM	#14
China Rider 27 Join Date: Dec 2018 Location: PNW Posts: 982	Carburetor related as you describe getting too much fuel. I would clean it good and check operation float as above. Watch out with the carb cleaner though on your bowl gasket it can cause rubber to swell and create issues. That is a genuine Mikuni VM22?
	1

11-12-2021, 01:05 PM	#15
Falkon45 Join Date: Aug 2020 Location: Savannah, Ga Posts: 759	check your coil, spark plug wire, and any electrical plug that is connected to ignition. I have a feeling something electrical is loose, and it's not your carb.
	1