BD125-8 Shuts Down between 5-6k rpm

djdanielalan · 10-24-2020, 04:28 PM

This thing is driving me nuts. Idles and revs and holds fine in neutral, but once in gear and hit 5000 rpm looses all power. Will even shut off. I've had to ride home at 3000 rpm. Replaced CDI and coil. Checked timing which appeared to be a tooth off. Even swapped carbs. Anyone experience this or have an idea?

djdanielalan · 10-26-2020, 08:08 PM

Nobody has had this experience? It's driving me crazy! There's not too many parts left I could replace on the bike to troubleshoot and it's still running like shit. I'm so tired of working on the bike, I just want to get it running properly so I can sell it and buy a Honda. This thing is junk.

Bruces · 10-26-2020, 08:25 PM

any Chance your cdi has a rev limiter in it ? If it’s a generic one from an atv or a smaller kids bike that might be how it was set up

djdanielalan · 10-26-2020, 08:32 PM

it does not. It started doing this even with the old cdi, which i now assume is still good. Doing wheelies with the crew and it started cuttting out in wheelies and on both wheels as well.

culcune · 10-28-2020, 02:04 PM

Quote:

Originally Posted by djdanielalan

This thing is driving me nuts. Idles and revs and holds fine in neutral, but once in gear and hit 5000 rpm looses all power. Will even shut off. I've had to ride home at 3000 rpm. Replaced CDI and coil. Checked timing which appeared to be a tooth off. Even swapped carbs. Anyone experience this or have an idea?

Kronik Racing in Simi Valley is close by you and Pete, the owner is pretty much the guru when it comes to Baodiao. However, before calling, have you adjusted the valve lash?

https://www.kronikracing.com/

djdanielalan · 10-28-2020, 06:21 PM

Quote:

Originally Posted by culcune

Kronik Racing in Simi Valley is close by you and Pete, the owner is pretty much the guru when it comes to Baodiao. However, before calling, have you adjusted the valve lash?

https://www.kronikracing.com/

Thank you! I couldn't find my feeler guage, so I overnighted some from Amazon. They actually just got here now lol.

culcune · 10-29-2020, 10:38 AM

I know that people have, in the past, suggested using aluminum cans as a feeler gauge (I forget what its thickness is), but that was for vertical singles as found in the dual-sports, and I think the gap was fairly close depending on bike's engine brand (usually Zongshen 2xx cc vertical thumpers). Not to mention, it seems that every single brand has their own intake and exhaust gap specs, so I guess using cans would be more for stuck on the side of the road valve lash adjustment, lol. BTW, what are the specs for these engines?

oincman · 10-29-2020, 05:18 PM

Is any of the emissions stuff disconnected? If not, check all your vacuum lines and tank vent. If it is disconnected, try hooking back up. Try removing the fuel filter and running straight to the carb. Just my .02

djdanielalan · 11-10-2020, 12:57 AM

Quote:

Originally Posted by culcune

I know that people have, in the past, suggested using aluminum cans as a feeler gauge (I forget what its thickness is), but that was for vertical singles as found in the dual-sports, and I think the gap was fairly close depending on bike's engine brand (usually Zongshen 2xx cc vertical thumpers). Not to mention, it seems that every single brand has their own intake and exhaust gap specs, so I guess using cans would be more for stuck on the side of the road valve lash adjustment, lol. BTW, what are the specs for these engines?

.003" intake and .005" exhaust (when using performance parts)
According to TBoltUSA https://tboltusa.com/store/tech.php?...%2C+and+Timing

djdanielalan · 11-10-2020, 01:05 AM

Quote:

Originally Posted by oincman

Is any of the emissions stuff disconnected? If not, check all your vacuum lines and tank vent. If it is disconnected, try hooking back up. Try removing the fuel filter and running straight to the carb. Just my .02

Emissions crap was removed the day I got the bike. I do have an inline fuel filter, but there is free flowing fuel coming from the line. I've been out of town and just getting back to work on this thing.

I'm convinced there's something electrical going on here. I noticed my led light kit reboot when I pressed the starter button the other night. CDI, coil and V/R have all been replaced. I have a new battery arriving tomorrow. Process of elimination lol.

**JerryHawk250** · 11-10-2020, 08:29 AM

Just throwing this out there but seen it before on here. Are you using a resister spark plug with a resister coil wire cap? That will cause a weak spark.

10-24-2020, 04:28 PM	#1
djdanielalan Join Date: Feb 2020 Location: Los Angeles, CA Posts: 10	BD125-8 Shuts Down between 5-6k rpm This thing is driving me nuts. Idles and revs and holds fine in neutral, but once in gear and hit 5000 rpm looses all power. Will even shut off. I've had to ride home at 3000 rpm. Replaced CDI and coil. Checked timing which appeared to be a tooth off. Even swapped carbs. Anyone experience this or have an idea?
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10-29-2020, 10:38 AM	#7
culcune Join Date: May 2006 Location: Yuma, Arizona Posts: 9,035	I know that people have, in the past, suggested using aluminum cans as a feeler gauge (I forget what its thickness is), but that was for vertical singles as found in the dual-sports, and I think the gap was fairly close depending on bike's engine brand (usually Zongshen 2xx cc vertical thumpers). Not to mention, it seems that every single brand has their own intake and exhaust gap specs, so I guess using cans would be more for stuck on the side of the road valve lash adjustment, lol. BTW, what are the specs for these engines? __________________ "They say that life's a carousel, spinning fast you got to ride it well..." TGB Delivery Scooter 150 TMEC 200 Enduro--carcass is sadly rotting in the backyard Last edited by culcune; 10-29-2020 at 11:41 PM.
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11-10-2020, 08:29 AM	#11
JerryHawk250 Moderator Join Date: Oct 2016 Location: Houma, La. Posts: 11,569	Just throwing this out there but seen it before on here. Are you using a resister spark plug with a resister coil wire cap? That will cause a weak spark. __________________ 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
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10-26-2020, 08:08 PM	#2
djdanielalan Join Date: Feb 2020 Location: Los Angeles, CA Posts: 10	Nobody has had this experience? It's driving me crazy! There's not too many parts left I could replace on the bike to troubleshoot and it's still running like shit. I'm so tired of working on the bike, I just want to get it running properly so I can sell it and buy a Honda. This thing is junk.
	0

10-26-2020, 08:25 PM	#3
Bruces Join Date: May 2018 Posts: 1,582	any Chance your cdi has a rev limiter in it ? If it’s a generic one from an atv or a smaller kids bike that might be how it was set up
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10-26-2020, 08:32 PM	#4
djdanielalan Join Date: Feb 2020 Location: Los Angeles, CA Posts: 10	it does not. It started doing this even with the old cdi, which i now assume is still good. Doing wheelies with the crew and it started cuttting out in wheelies and on both wheels as well.
	0

10-29-2020, 05:18 PM	#8
oincman Join Date: Nov 2019 Posts: 99	Is any of the emissions stuff disconnected? If not, check all your vacuum lines and tank vent. If it is disconnected, try hooking back up. Try removing the fuel filter and running straight to the carb. Just my .02
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