HiBird or Roketa

[Weldangrind]

If it idles well with the choke off, the slow jet is likely to be clean. If the engine stumbles upon opening the throttle, the pilot mixture screw needs to be backed out a bit. Maybe one quarter turn.

[dibe]

It hardly wants to run with the choke on. I will try the idle mixture screw...I mean I twist the throttle full bore and it just cuts out right away.

I cleaned the carb last night and move the needle shim down one to no avail. I am going to move the needle back to the stock position and see what happens. I a feeling the needle was ON TOP of the clip and not under it as it just slid out last night when the clip was still in the top of the carb.

On a side note, I went and got the plates for it today. Here are a couple of pictures from on my way home.

[FastDoc]

Nice pics. Your bike thinks it's a crouching tiger in the savanna!

I think Weld's got it fugured. Leave the clip for now and fiddle with the idle mixture screw. That may be all you need.

[SpudRider]

Thanks for posting the photos of your bike in it's native habitat! I really like the looks of your Roketa DB-05.

Spud

[dibe]

Thanks guys....We were playing hide and seek

Still no luck with the carb. I tired it in the 3 bottom positions of the needle grooves and went through the range with the idle mixture all the way up to 3.5 turns out and the engine would cut out every time I went to wide open throttle.

The only thing that helped it was when I had the choke out about 1/3rd of the way out and then I was able to go wide open throttle with out it cutting out right away.

I think it might be time for bigger jets.

[FastDoc]

How rapidly are you opening the throttle?

These direct slide (non-CV) carbs will lean out and stall if the throttle slide is pulled too rapidly. That's normal.

[dibe]

I go from the throttle being at rest to opening it all of the way.

[FastDoc]

You may be trying to fix a problem that does not exist. How does it behave on the road rolling the throttle gradually?

[dibe]

It seems to be going OK. But even if I give it lets say half throttle there is huge flat spot in the lower ends.

Guess I'll have to pay more attention next time I am out to see how it reacts when I am a bit more gentle.

I used to have a carbed Sportster so I am some what familiar with carbs. I know this is a much smaller bike but I thought the throttle should have a smooth acceleration more so then it does.

[katoranger]

It may be time for a Weld endorsed 30mm mikuni.

[Weldangrind]

You're right, dibe. Small engines are somewhat more sensitive to jetting and elevation, and some careful tuning should make it smoother.

Poor idle is mostly due to slow jet size or debris, off-idle stumble is corrected with the pilot mixture screw, unless the slow jet is too small. If you need to turn the pilot screw out more than two turns, the slow jet size should be increased. Mid-range flat spots are normally fixed with clip adjustments and top end stumbling is due to main jet size or debris.

If a bike or atv has a Keihin clone round slide carb, the first thing I do is swap in a 30mm Mikuni. Jets are much easier to find for the Mikuni, and the entire carb is usually less than $40 including delivery on eBay.

[2LZ]

I have the same motor in my XMoto and it has a very snappy throttle. Better response than the CV carb on my Q Link.
Just keep tinkering. You'll get it.

Make sure all your hoses are good and there's no grunge in the tank clogging your petcock either. Sometimes these bikes really collect a lot of gunk from shipping and sitting and also, Chinese rubber (especially hoses) is notoriously horrid.

Very clean bike you have! I like the pushrod also. Not as much top end as my OHC QLink but more bottom end for trail riding and climbing.

[dibe]

I just wanted to report in that after I put on the bigger rear sprocket and little fooling around with the clutch, I have been able to do some wheelies...