FMS works very well with 2084ss/41021 or 9853ss

to the guy running 25% , what's wrong with 30% ?

Make sure and check your deck heighth , that's usually the culprit on the spittin and sputterin crap .

The other culprit I have seen cause that is bad fuel

Sometimes a glow plug but not usually the case

I would recommend to shim at .65mm if using 25% using a medium medium hot plug such as 97t or 87t

And above all enjoy your rc car engine