Being a bit of an engine freako (I drive a Ford powered Volvo), I elected to keep my 100 -to see what was "UP" with it.
I could see why RCS elected to do the recall- performance on smaller mufflers , simply was not what was expected.
Inasmuch as I personally do not use smaller mufflers - I thought I would -on my own hook, poke around
Once I got it loosened up - I tried a wide variety of exhaust setups - on my test stand-
The results were interesting.
this engine was designed to maximize the power potential of large, longer tune systems - these are popular --in Europe but not that common here
On these setups -this engine is very strong -yet -very docile!
Not in the least bit peaky in midrange.
Totally unlike the fussy pipe setups I knew and hated in the past -on my pattern models.
JMB quiet canister setups which work extremely well on my other ZDZ engines (my 210 and JMB cans, is VERY strong) still did not seem to be bringing up full power potential.-
So----- to put it in simple terms - -the engine is tuned for pipes which raise the TORQUE level
And ZDZ did the best job at this I have ever seen.
The catch?
If you don't use those, you may not get the performance you anticipated.
At the risk of raising some eyebrows - I have to say that the increased performance using the large tuned setups , provides performance that is better than any 100 size engine I know of.
It is - notably better than my best ZDZ80 singles -on pipes - which as about as good as most current 100 twin engines.
I have asked RCS about this - they were very concerned that this engine, also perform well for the avg modeler- so they did the recall and the ZDZ people are working on it.
I am confidant it will all turn out well.