da-50 will not richen up/high end needle

[1rcripper]

new da-50 2.5 gallons ran, lawn boy 32:1, 24*8 nx balanced, fresh gas, carb screen clean, plumbing clean, large tygon tubing, tank clunk line good,

engine will richen on low but not the high, back out high needle 3turns no diff, like no sputtering, or any rich indication

based off my dirtbike 2stroke tuning knowledge, sounds like the high is tapped out for any richer condition, like it needs a diff jet, orifice, or needle, something to that nature, i havent looked at that side of the carb yet

anyways i'm in central fl, if that helps with a tuning effort


thanks for any help rodney

[DATech]

Hello Rodney
The majority of the 8,000 DA50's sold operate at less than 1,000 ft asl. While sometimes the high end will not get overly rich, we have had no problems with engines running too lean due to the needles not being able to go rich enough.
If the carb could go overly rich, I am sure it would give some people some peace of mind.
Other carbs tested in the correct size range, that have the ability to run overly rich, have had some mid range/transition issues.
Drilling the high orifice has had mixed results so far, but I would think some minor opening of the orifice could produce an overly rich capability without disrupting the mid-range too much. Some have reported good results and others have had problems.
What works well with one person's prop, fuel, exhaust, altitude, temp, humididty, exhaust system, engine break-in/health status, can, and most often is, different than someone else's.
If you wish to try drilling it out, you may find the extra rich cushion you are looking for.
The prop size can be a bit of a factor with needle settings, but the exhaust system is generally much more of a factor. We have seen some canister syetems require the needles on the DA50 to be set more than a 1/2 turn leaner compared to other more common exhausts.
As the DA50 production continues, we will continue to look at ways to improve it in any way we can.
On a side note... The subject makes me ponder the future...... What if fuel injection is perfected for giant scale gas engines...? Will we trust the system to deliver enough fuel (like our modern cars), or will we need to have an adjustment to see it run overly rich?
Just food for thought...... ;o)
Thanks
Dave