Help With Carburetor!

L

locochris

New Member
Hi i just built my motorized bike with a Grubee Race 80/66cc Black SkyHawk Angle which came with a CNS V2 Carb and i just put gas in it and theres this little white tube on the bottom of it that leaks out gas and i cant find where you put that i looked every where and theres no hole to put it in heres a picture
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So when i tryed to start it up i had a hard time doing it then it turned on sounded weird and went 18 mph i never opened up the carb before putting it on all i did was put it on the bike do i have to do something to the carb fix the problem of turning the bike on?
zpt
 
I think that is the over flow line. Maybe you have a bad float? Is the leak constant or is there a little residue of fuel on it after running?
 
It leaked the first time i put gas i think its fine i messed with the air and fuel mixture screw and idle screw that made it turn on quicker but its going slow about 18 to 20 the air fuel is one turned out of fully turned in.
 
can't help ya i never had that problem and i have an identical carb. maybe your carb is at too much of an angle?
 
Is there anything else that could be causing the problem of it going 18mph could it be the fuel mixture i put 2.6 oil in to a gallon of gas and other things when i noticed turning it on when i messed with the screws smoke come out of the muffler. anything inside the carb that could cause the problem i found a topic of my carb this is the one http://motorbicycling.com/f34/inside-2010-grubee-skyhawk-cns-carb-25062.html please post what could be causing this. and what does the .75 mean screws in or out? sorry for all the questions
 
There is no specific thread, you are just one of many people who I've heard is having trouble, good luck :)
-LS
 
This was on Spooky Tooth a while back.
Ports on the CNS carburetor-
The pink tube that comes attached to the carb out of the box can be disregarded. The port tubes are for various purposes. One port tube is for equalizing pressure in the float bowl, and another is a vacuum.

Adjusting the carb-
The front screw is for the idle, the rear screw is for air/fuel. Set the idle to a good speed. Then "blip" the throttle and listen to how long it takes for the idle to return back to normal. Adjust the air/fuel screw so that mix just gets rid of the lingering idle. Run the bike for a while and pull the spark plug to check the condition. If the plug is dry, tan or white then you should turn the air/fuel screw in so that you richen the mixture. This will help keep your engine cool and well lubricated, especially at higher rpms.
 
I have got to agree that the old NT carbs were MUCH easier to tune but I am in the process of learning about the CNS since my last four motor kits came with that carb. These guys are right about that bottom tube. If you take your bowl off you will see that it is attached to a tube that runs up to the top of the bowl area. That makes it a bowl vent/overflow. The fuel level should never get that high so you may have to adjust your float accordingly. Also check the needle and seat for proper sealing. Do this buy tipping the carb upside down and try to blow though the fuel inlet. You shouldn't be able to. I am going to make sure tomorrow but I believe the mixture screw only effects the idle circuit. Same adjustments apply for the CNS as the NT. Needle clip for part throttle, Main jet size for WOT. The last two I worked on were way lean to the point they would bog bad when I opened the throttle. After checking the basics such as air leaks and float setting I drilled the main jet a size bigger and now they both seem to be running much better.
 
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Hi, I just bought the same kit and I am having trouble adjusting the carb so the engine can idle. Also, I can't find the way to properly align the chain, it keeps going off. Now, I undestand there are tons of post that may address this two issues, but for some reason, I can not follow the words with what I have to do. I am completely new to this and English is not my strength. So I beg for videos, please.
 
renzr55 said:
Hi, I just bought the same kit and I am having trouble adjusting the carb so the engine can idle. Also, I can't find the way to properly align the chain, it keeps going off. Now, I undestand there are tons of post that may address this two issues, but for some reason, I can not follow the words with what I have to do. I am completely new to this and English is not my strength. So I beg for videos, please.
Click to expand...

is your sprocket on even remotely even? the closer to perfect the better but it shouldn't throw the chain unless it's pretty uneven, as far as alignment goes you can use washers between the hub and drop outs to get a bit better of alignment, or you could get a 2x4 and space out your drop outs even more, and use washers to make it still grip.
 
I will get the sprocket as even as possible. As far as the alignment goes, how do I know it is aligned or not, "use washers between the hub and drop outs", where is this?
 
having the same carb problem. Leaked gas out the overflow constant. messed with the float tab and after taking the carb apart 6 or 7 times i found a happy spot where i could get it to run and not leak gas. Performance is not good though. Can't give it full throttle and have to mess with the choke alot to eventually go 20 mph or so. Tryed all the needle clip adjustments, tuned the idle and air all different ways, sealed the carb. around the intake with high heat stove sealant, and port matched and polished the air intake and the exhast. what more can i do? I got plenty of gas flow into the carb.took the fuel valve apart and drilled it bigger. Gas tank is venting as well, I can drain my tank with the cap on in about 4 mins. I'm thinking I need to drill the main jet bigger but i also heard maybe the problem is that it is too big already. Sounds like its starving for more gas to me. Help Someone. Theres alot of us out there sruggling with this carb. Something aint right
 
renzr55 said:
I will get the sprocket as even as possible. As far as the alignment goes, how do I know it is aligned or not, "use washers between the hub and drop outs", where is this?
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the groove you slide the axle into, those are called drop outs. you put a washer on the axle real close to the hub and then put the axle back into the drop outs, this will allow you to shift your sprocket to one side or another roughly 2 millimeters at a time.

the chain is aligned when the chain coming off the drive sprocket (on the motor) makes a straight line to the top of the rear wheel sprocket.

you want to get the alignment as close to perfect as possible, doing it with kit sprockets can be pretty hard and frustrating but it's doable, sprocket adapters can be much easier to set just right but also cost a bit more money.
 
matthurd said:
the groove you slide the axle into, those are called drop outs. you put a washer on the axle real close to the hub and then put the axle back into the drop outs, this will allow you to shift your sprocket to one side or another roughly 2 millimeters at a time.

the chain is aligned when the chain coming off the drive sprocket (on the motor) makes a straight line to the top of the rear wheel sprocket.

you want to get the alignment as close to perfect as possible, doing it with kit sprockets can be pretty hard and frustrating but it's doable, sprocket adapters can be much easier to set just right but also cost a bit more money.
Click to expand...
There is a plus or minus tolerance on this straight shot chain line. Look here this motor is very wide at its sprocket out put. This guy ran the chain close to the wheel. http://motorbicycling.com/f47/death-china-70cc-now-onto-morini-8952-2.html Front derailleurs on multiple crank sprockets don't have a straight chain line.. There is a little forgiveness..
 
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