Bd125 not starting after carb swap and emissions delete

Jro79553 · 05-30-2023, 09:49 AM

Hi all,

Trying to get a bit of advice,
Just put a mikuni 26mm carb knockoff on the bike,, deleted the emissions such as closing off the egr pulling the air box that evap can under the seat as well as the lines connecting the egr to everything. I have the vent hose for the gas tank and the crank case filtered and ziptied up.

I've had it started twice since. Once just to test it before I closed off the egr, and the second time after everything was put backon. It seemed to be smoking a bit when I had it started little whispery white smoke from by the motor. Wasn't able to track it down right off. I'm wondering if it was running rich that's why I got the smoke? Hopefully othing internal went wrong.

I haven't been able to get it to start since.

I have spark I have fuel i have air

When I pull the filter and put my hand over the intake it sucks my and and I get fuel on my hand as well. I have the carb air fuel screw 1.5 turns out. Could the jets be the problem.

I'm definitely lost on this one. I almost want to put the old carb back on and see if I have the same issues.

The only 2 things I have not done is swapped out the battery for a new one this one is junk, came dead and needs a jump pack. Waiting on payday to get one. As well as it's the original spark plug.

Barnone · 06-01-2023, 08:57 PM

Why did you swap the carbs? Was the bike running bad? I would put the carb you took off back on and back off any other mods.Maybe the 26mm carb is too big for your 125cc engine. Did it come with the PZ19 ?

bogieboy · 06-02-2023, 10:14 AM

A 125 thats otherwise stock will be a bear to get going on a VM26... i ran a vm26 on my 110cc pocket bike but that was ported head and race cam, even then it was a bear to start, because the large venturi didnt have enough airspeed down low to reliably draw fuel...

nobade · 06-02-2023, 11:41 AM

Would have to agree. That's way too much carb for that engine. Good for a 350cc or so.

culcune · 06-02-2023, 02:12 PM

Contact Pete at Kronik Racing. He is the defacto guru on the Boadiao/Boom engine and various bikes (he sells a bunch of the Grom-ish clones) and supplies parts for them. He goes to Boom's So. Cal. warehouse a few days a week so has, or can get, any parts for the BD bikes. https://www.kronikracing.com/boom-vader-125-10.html

bogieboy · 06-03-2023, 10:34 AM

Quote:

Originally Posted by nobade

Would have to agree. That's way too much carb for that engine. Good for a 350cc or so.

If its the vm26 clone that is readily available for cheap, its not terribly oversized with supporting mods, remember that most of the 200cc bikes perform well with a 29-30mm carb, rhe vm26 clones are 26mm, not the same specs as a true VM26....

Barnone · 06-04-2023, 08:48 AM

What happened to the original poster? One post and done?

buzz · 06-04-2023, 06:03 PM

He put the old carb back on.

05-30-2023, 09:49 AM	#1
Jro79553 Join Date: May 2023 Posts: 1	Bd125 not starting after carb swap and emissions delete Hi all, Trying to get a bit of advice, Just put a mikuni 26mm carb knockoff on the bike,, deleted the emissions such as closing off the egr pulling the air box that evap can under the seat as well as the lines connecting the egr to everything. I have the vent hose for the gas tank and the crank case filtered and ziptied up. I've had it started twice since. Once just to test it before I closed off the egr, and the second time after everything was put backon. It seemed to be smoking a bit when I had it started little whispery white smoke from by the motor. Wasn't able to track it down right off. I'm wondering if it was running rich that's why I got the smoke? Hopefully othing internal went wrong. I haven't been able to get it to start since. I have spark I have fuel i have air When I pull the filter and put my hand over the intake it sucks my and and I get fuel on my hand as well. I have the carb air fuel screw 1.5 turns out. Could the jets be the problem. I'm definitely lost on this one. I almost want to put the old carb back on and see if I have the same issues. The only 2 things I have not done is swapped out the battery for a new one this one is junk, came dead and needs a jump pack. Waiting on payday to get one. As well as it's the original spark plug.
	0

06-02-2023, 02:12 PM	#5
culcune Join Date: May 2006 Location: Yuma, Arizona Posts: 9,056	Contact Pete at Kronik Racing. He is the defacto guru on the Boadiao/Boom engine and various bikes (he sells a bunch of the Grom-ish clones) and supplies parts for them. He goes to Boom's So. Cal. warehouse a few days a week so has, or can get, any parts for the BD bikes. https://www.kronikracing.com/boom-vader-125-10.html __________________ "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
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06-01-2023, 08:57 PM	#2
Barnone Join Date: Feb 2007 Posts: 1,357	Why did you swap the carbs? Was the bike running bad? I would put the carb you took off back on and back off any other mods.Maybe the 26mm carb is too big for your 125cc engine. Did it come with the PZ19 ?
	0

06-02-2023, 10:14 AM	#3
bogieboy Join Date: May 2013 Location: finger lakes NY Posts: 2,061	A 125 thats otherwise stock will be a bear to get going on a VM26... i ran a vm26 on my 110cc pocket bike but that was ported head and race cam, even then it was a bear to start, because the large venturi didnt have enough airspeed down low to reliably draw fuel...
	0

06-02-2023, 11:41 AM	#4
nobade Join Date: Apr 2021 Posts: 6	Would have to agree. That's way too much carb for that engine. Good for a 350cc or so.
	0

06-04-2023, 08:48 AM	#7
Barnone Join Date: Feb 2007 Posts: 1,357	What happened to the original poster? One post and done?
	0

06-04-2023, 06:03 PM	#8
buzz Join Date: Dec 2020 Location: Dayton Pa. Posts: 953	He put the old carb back on.
	1