BD125-15 BOOM VADER NO FUEL Question!!

[Whisky]

The adjustment at bars is controlling the movement of the slide in a more precise manner, there needs to be some free play in the throttle, Once that is set then u lightly turn idle screw on carb to stop the slide from going down. I originally was trying to set idle with the screw and was having all sorts of idling / running isues, Once I found out I was doing it wrong my issues went away
I guess the importance of having the free play at the throttle is what matters.

[scoot newb]

Originally Posted by sirmaxwell

the air/fuel is probably covered with a brassy"safety"/dont mess with me cap I need to drill out to adjust the air/fuel mix..Am I right?

Yes, or ditch the stock carb.

[sirmaxwell]

Originally Posted by scoot newb

Yes, or ditch the stock carb.

in good time Im probably waiting until at least after break in for that--which I think is 300km-180ish miles or more ...I know thats when the first oil change is due and the sticker on top of the oil fill says in Chinglish dont surpass 50 Kilometers Per Hour durning break in--which is 30MPH, I have mine set to MPH although I figured out how to switch it to KMH if I want to feel like Im going faster hehe-- then the sticker went on to say something about change oil at 300km but doesnt say the break in mileage--maybe the book says it if i read that again..

I think I broke 40 miles maybe even getting close to 50 miles on the odometer today!! so maybe next week it will be broken in then I will go for plates by then for sure

[sirmaxwell]

Originally Posted by Whisky

Check tank vent hose

SO I filled my tank very full and I had the problem again tonight where it stalled, didnt want to start again. I left it alone for awhile still no dice...then I blew into and sucked smelly gasoline air out theu the rank vent and bingo fired right up!

so I think my bike is a bit cold blooded--MIGHT have had a pinched line before but pretty dogone sure I have a tank vent problem.

After I manually got air into and out of the tank with my mouth (not sure which way Im supposed to be going with the air although I know the tank vent obviously vents the air outward) then I took it for a couple miles ride and stalled again--again wouldnt start and I "manually vented" the tank vent hose again and it fired up instantly again!!

I think you were originally right with one of the first comments WHisky--the question is do i replace it? where do I get a new vent? or do I get rid of it..somehow? I mean I had checked the tank vent hose before when you said to but all I did was make sure it wasnt pinched, detached or ripped--now I think the vent itself or the placement or something with it is somehow faulty


Also thanks for the reply on the adjustment--I noticed the tiniest turn on the carb screw like a 1/8th turn changes the idle speed A LOT--around one bar on the tachometer which is something like 333rpms--so I will definitley try adjusting the handlebars adjustment next chance.

[Whisky]

There's a 1 way valve on the vent hose it's under the tank towards. The handle bars, I took mine off and just have the hose.

[sirmaxwell]

Originally Posted by Whisky

There's a 1 way valve on the vent hose it's under the tank towards. The handle bars, I took mine off and just have the hose.

Hopefully I will find the time and stop being lazy and just take off the fairing and take off the valve tomorrow and be done with it. I rode it today with the same deal-- seems like maybe worse in cold or maybe it jus happens at night because I have been running it during the day before that. i dunno but i am really sick of venting the tank manually--makes me almost sick and cant be good for my health!!

Thanks again for the answer, i expect this to solve my problem unless I have a sticky internal carb problem instead or in addition to the suspected valve problem.---The reason i am Guessing IT COULD BE JUST THE CARB instead of the vent itself is because when I blow into the vent hose i think I can feel air coming out the carb drain --so it is somehow linked thru air pressure or i dont know--either that or I somehow have a carb ven lol ---I definitley want to map all my hoses for air/fuel and emissions when I take it apart to be sure of this issue and for anything like mods or other troubleshooting in the future~~!

[Lardog]

Hey all, new to the forum and posting because I have the exact same bike as the OP with the exact same engine and (drum roll) the exact same problem. Took it out on my first ride yesterday afternoon and ran great for a few miles during my first break-in run but stalled at a stop light and wouldn’t start for nothing. Ended up pushing it a mile home. After letting it cool down it started right up. I originally thought my aggressive break-in method broke it but after reading this thread I’m thinking it’s a gas issue also.

My solution before I continue any more break-in is to upgrade the carb and re-jet while at the same time removing all the CARB emission junk. The carb upgrade seems straight forward but is there a diy on removing the emissions junk? In all my searching I’m unable to locate anything.

Thanks to all that has replied to sirmaxwell for help as you’re now helping me as well.

[RedCrowRides]

Some of the "pieces and parts" of the emissions stuff are laid out differently between the Gen1 and Gen2 models , but here is basically what you need to do ,and what you need to cap off.,and more or less where you need to look for it at. The air pump will be on the front(ish) of your engine ,with the inlet tube going into the head on the shifter side, opposite more or less where your exhaust bolts up.Take that pump off ,you will see one hose that goes to a connector on your intake - block that little pipe on your intake off with a carburetor vacuum cap.There will be a larger hose that connects to your airbox that comes from the engine , on the top side more or less right over your front sprocket, put a breather on that hose. When you take the airpump offf there will be a big black metal pipe that goes into the engine,if your bike had a bracket that attaches the air pump that can be used as a block off plate , do that. If it doesnt, you can leave that black metal inlet pipe on , and just cap it off with a carburetor vacuum cap.

The plastic can that is part of the emissions / air pump etc is at the rear of your gas tank , right under where the back two bolts holding the tank down are, under the seat. it has a black zip tie holding it in, cut the zip tie and get it out of there. The gas
line elbow from the tank sits jammed against that plastic can and i have seen the gas line be crimped damn near shut there, so taking that plastic can out of there takes the crimp off it . Since you are in there now, it would be a good time to replace the very crappy stock fuel line with some good silicone fuel line .


Ill try to post some pix here later to give you an idea of where all this stuff is but it really isn't hard to find . While you are in there doing all this you might want to take the stock air box out and replace it with a pod filter ,which will help performance even if using the stock carb.

[Lardog]

Originally Posted by RedCrowRides

Some of the "pieces and parts" of the emissions stuff are laid out differently between the Gen1 and Gen2 models , but here is basically what you need to do ,and what you need to cap off.,and more or less where you need to look for it at. The air pump will be on the front(ish) of your engine ,with the inlet tube going into the head on the shifter side, opposite more or less where your exhaust bolts up.Take that pump off ,you will see one hose that goes to a connector on your intake - block that little pipe on your intake off with a carburetor vacuum cap.There will be a larger hose that connects to your airbox that comes from the engine , on the top side more or less right over your front sprocket, put a breather on that hose. When you take the airpump offf there will be a big black metal pipe that goes into the engine,if your bike had a bracket that attaches the air pump that can be used as a block off plate , do that. If it doesnt, you can leave that black metal inlet pipe on , and just cap it off with a carburetor vacuum cap.

The plastic can that is part of the emissions / air pump etc is at the rear of your gas tank , right under where the back two bolts holding the tank down are, under the seat. it has a black zip tie holding it in, cut the zip tie and get it out of there. The gas
line elbow from the tank sits jammed against that plastic can and i have seen the gas line be crimped damn near shut there, so taking that plastic can out of there takes the crimp off it . Since you are in there now, it would be a good time to replace the very crappy stock fuel line with some good silicone fuel line .


Ill try to post some pix here later to give you an idea of where all this stuff is but it really isn't hard to find . While you are in there doing all this you might want to take the stock air box out and replace it with a pod filter ,which will help performance even if using the stock carb.

Wow, thanks red, I really appreciate it. I’ll use these direction to start removing this stuff. After pushing it home yesterday it’s funny how a consistent running bike takes priority over any other modifications. The carb will still be getting done. Thanks again!!!

[RedCrowRides]

I recommend removing all that smog / emissions stuff if your state doesnt inspect motorcycles for it. That evap canister under the tank crimps the fuel line , for one and the rest is, it's a rat nest of potential vacuum leaks and stuff to get clogged up and cause issues.The highest reliability is gained by reducing the engine to it's barest, essential components then making those as bullet proof and reliable as possible. All that Emissions stuff does is add performance decreases and failure points too many to mention ,and it doesn't help it is made from cheap chinese materials which are prone to failure / reduced longevity, furthering the failure factor and potential for aggravation . I think i 'll go outside and beat mine with a ball bat , even tho its already off lol, DIE AIR INJECTOR CAN DIE !!! Hahahahahah!

[Lardog]

Originally Posted by RedCrowRides

I recommend removing all that smog / emissions stuff if your state doesnt inspect motorcycles for it. That evap canister under the tank crimps the fuel line , for one and the rest is, it's a rat nest of potential vacuum leaks and stuff to get clogged up and cause issues.The highest reliability is gained by reducing the engine to it's barest, essential components then making those as bullet proof and reliable as possible. All that Emissions stuff does is add performance decreases and failure points too many to mention ,and it doesn't help it is made from cheap chinese materials which are prone to failure / reduced longevity, furthering the failure factor and potential for aggravation . I think i 'll go outside and beat mine with a ball bat , even tho its already off lol, DIE AIR INJECTOR CAN DIE !!! Hahahahahah!

Lol!!!! I agree completely about the emission components causing extra failure points. I’m in North Carolina so no need for the stuff. Another member on the post mentioned changing out the fuel line since the once is ships with is subpar so I’ll do that while I’m in there. Thanks again Red!!!

[cbrfxr67]

My Vader really 'broke in' around 500 miles if I remember right. I mean you can notice it running better. I could.
If you're up to it, I'd take all that emissions stuff off and do the minor upgrades to get it running well. I really like the cheap Molkt carb 26mm on Ebay. Anyways, seems like you're learning and reeling it in to running better as you do. Great read on your progress

[RedCrowRides]

@cbrfxr67 I also like the Molkt carb, i wasn't really familiar with it but a friend of mine runs one and has had great results with it, I like the " push / pull" choke design ,and the Molkt I have to admit is easier to adjust the air fuel and idle mixtures as far as ease of access to the screws for doing so than the Mikuni .The Molkt uses Mikuni jets so those are cheap and plentiful and easily obtainable.

Anyone considering swapping out carbs should really give the Molkt a look, I already put a VM22 Mikuni on my Vader or I would go with a Molkt , i really like the easier to get to adjusting screws ,those can be a real pain on the Mikuni especially the air / fuel mix one.

[Lardog]

Originally Posted by RedCrowRides

Some of the "pieces and parts" of the emissions stuff are laid out differently between the Gen1 and Gen2 models , but here is basically what you need to do ,and what you need to cap off.,and more or less where you need to look for it at. The air pump will be on the front(ish) of your engine ,with the inlet tube going into the head on the shifter side, opposite more or less where your exhaust bolts up.Take that pump off ,you will see one hose that goes to a connector on your intake - block that little pipe on your intake off with a carburetor vacuum cap.There will be a larger hose that connects to your airbox that comes from the engine , on the top side more or less right over your front sprocket, put a breather on that hose. When you take the airpump offf there will be a big black metal pipe that goes into the engine,if your bike had a bracket that attaches the air pump that can be used as a block off plate , do that. If it doesnt, you can leave that black metal inlet pipe on , and just cap it off with a carburetor vacuum cap.



The plastic can that is part of the emissions / air pump etc is at the rear of your gas tank , right under where the back two bolts holding the tank down are, under the seat. it has a black zip tie holding it in, cut the zip tie and get it out of there. The gas
line elbow from the tank sits jammed against that plastic can and i have seen the gas line be crimped damn near shut there, so taking that plastic can out of there takes the crimp off it . Since you are in there now, it would be a good time to replace the very crappy stock fuel line with some good silicone fuel line .


Ill try to post some pix here later to give you an idea of where all this stuff is but it really isn't hard to find . While you are in there doing all this you might want to take the stock air box out and replace it with a pod filter ,which will help performance even if using the stock carb.

Hey Red, just wanted to thank you again. I followed your directions on removing the emissions stuff and they worked out great. I was able to get my new Mikuni installed and the bikes running really good now. For some reason I thought removing this stuff we be more involved but with your instructions tools all of 30 minutes. I’ve decided to hold off on finishing the break in until I get my 16t front sproket. With the stick front sprocket first gear is non existent and doesn’t help with break in. Thanks again for helping a neeb out, hopefully some day I can give back.

[RedCrowRides]

@Lardog Hey man, just glad you got it all done with no issues and it's running good !
I try to help people as much as I can, to pay back for all the help I got when I was new here myself !

And yeah, i agree the first gear with the stock sprockets is basically unusable, it's so low you cant hardly go 5 feet before you need to hit 2nd lol !