I bought the upgrade kit for my DD2, at the same time threw in a new piston.
After our first club race wasnt too happy with the performance. Im still new to karting so take my feedback with a pinch of salt.
Basically i was 2sec slower than my previously set times and felt it lacks bottom end. I am over the class weight by 10kg which is probably why it affected me so much more than others and after the festive season its probably taking me some time getting back into it resulting in my slower times.
Our track is definitely not flat either, we climb some pretty steep inclines so having a motor with good bottom end is vital which is where im losing the bulk of my time now.
If im not mistaken the squish gap has been increased slightly on these new motors which is also a contributing factor to the lack of bottom end.
The lack of bottom end has also been felt by everyone not just me, so the guys have been doing allot of testing with a combination of the older carbs and PV’s coupled to the new motors. Some of found improvements by doing this other found it to be worse by mixing and matching.
So end of the day i think its purely a matter of conducting some more testing with the new upgrades in an effort to find that ‘sweet spot’ again.