The DA50 is going to run like crap for the first few tanks... don't sweat the burbles until after you run a gallon or two through it. You are only concerned with three things at this point - NO deadsticks, keeping the engine cool, and seating the rings. Ignore the burble.. it just means its running rich which is OK for new engine.


Once you have a gallon or two run through it and its still blubbering away...
You need to pay attention to two things - your low needle is too rich (high needle may be as well) ... and the length of the headpipe to the can may be too short.

Tune the engine so that WOT produces max RPM, then back needle off (richen) until RPM drops about 200 - do this by ear.. no real need for a tach. Once set, adjust the low needle until a rapid transition from idle to WOT produces a slight hesitation. Back off (richen ) the low needle until that hesitation JUST goes away.... low needle is set where it needs to be once transition is very clean. Re-check high RPM again. Repeat the process if necessary until engine runs smooth. FLY the engine, don't just try to get it right on the ground... take the cowl off if needed to get access to the needles.

If you cannot get the engine to stop blubbering with the needle adjustments - your headpipe is most likely too short. The headers are adjustable as are the slip collars. Cans are meant to be tuned to the engine and some times moving the pipe length out can make a huge difference. I do this only after the needle changes. In general the longer the pipe the better on cans so play with it... move the pipes out and see if there is a diff.... you might even have to move them IN and trim the headpipe to get the right length. Usually you can find the ideal length too from posts here on RCU... I found my QQ106 length this way... worked perfect first time...

Just as an FYI - there really are no "pressure" issues with the DA50 (or any rear mounted carb)... despite the chatter - its more of a myth than fact. The mods that DA made were to make needle tuning easier and to prevent fuel from pooling in the reeds at low RPM - all transition or burble issues can be resolved in the needles (assuming the carb is not bad)... all it takes is patience which most people don't seen to have...


DP