Increasing Loss of Power (Choke Issue?)

2011 Grubee Skyhawk
High Test Chevron gas (California)
HP2 100% Synthetic two stroke oil
40:1


CHO!!! I'm currently enjoying the ups and downs of my first mechanical project ever.


A couple weeks back, just as I started to notice an increase in power and acceleration during break in, my engine decided it was time to turn things around and decrease performance each time i go for a ride.

Just before I started to notice poor performance I was on a ride and my choke lever assembly rattled loose and all parts scattered across the road. I wasn't able to find them all and I'm pretty sure this is where my issue is coming from.

I live in Los Angeles and it never gets cold here so I figured it was no big deal if my choke assembly was not functioning since I dont use choke anywways.

But now my bike starts up fine and runs great for about three seconds then loses power and starts to bogg after maybe thirty seconds of riding.

I tried to remove the whole choke assembly from the carb and that just made it worse. I dont know what to do next any ideas out there?

I took off the air filter to look into the carb and I see where the choke cable and the plug thing on the end of the cable fit into the carb. there is a little hole that can either be open or closed by the choke cable. When the choke lever is in off position should the hole be open or closed? The hole is VERY small.


Thanks for any help you can send my way. This motorbike is my only mode of transportation to my job (15 miles away) aside from the bus. I need to get my bike running again so I can stop taking the crappy bus!!!!!

Thanks 2DOOR

When you say "Big Hole" are you talking about the main hole where the throttle cylinder moves up and down? Right now when the throttle is all the way on the hole is all the way open. When the throttle is all the way off the cylinder closes the hole about 4/5ths.

I dont see any other holes in there.

I tried to run with the choke cable all the way tight (little hole open) and it felt like the choke was obviously on. I tried with the cable all the way slack (little hole closed) and I just have very little power like I described earlier.

Is there anything else aside from the choke that could be going wrong here?

Thanks GEARNUT great input,

Sorry for the load of questions Im about to ask...

My carb is in fact a CNS carb. Are you talking lean as in air to fuel or lean as in gas to oil? I may have went too lean on my fuel mixture too soon. I did one gallon 20:1, two gallons 24:1, and now im running 40:1

I noticed that my air/fuel adjust screw is sealed off and I cant adjust it. Also my needle valve only has one position for needle clip adjustment. Is my carb worth upgrading?

If I have an intake leak is it fixable? The bushing between the hose clamp and carb looks a little misshaped and on the inside of that bushing the rubber ribs are pealing off. Probably because I have taken the air filter off and on so many times.

Whats the best way for me to test for an intake leak?

Thanks again

Thanks for those links. After reading through the first one I realized that my carb wasnt "snapped" on all the way. I pulled it off and slid it back on, then shoved it on a little farther.

We'll see how it runs now.

Thanks man you're totally right! I checked the spark plug today and it was all sopy wet and black. Im gonna upgrade all my spark plug and boot and enricher lever and whatever else I can afford right now and then let you guys know how it works out.

Is there a way to "micky mouse" close my enricher while i'm waiting for all my replacement parts? I would really like to start riding again so I can stop taking the bus!

So I ended up getting a new carb. I got the nt Speed Carb. It started up first try and it feels great. When I have more time i will try to tune up the cns and see if I cant get it to work. Thanks for all the help glad to be back on the road.