I was just reading what Snowbird had wrote earlier about a tech telling him his optimax wasnt supposed to be run for any length of time in the 2000 r.p.m range. The tech was telling the truth. The reason for it is this. There is two modes the optimax runs in. Homogeneouss and stratified.
Homogeneous fuel is injected on the intake stroke and dispersed.
Stratified fuel is injected during compression stroke
Simple terms, stratified fuel charge is an ultra lean burn for fuel emissions at low load. So when you run it around the 2000 r.p.m it hasnt changed into the homogeneous fuel stage, so your engine is running extra lean, and more likely to cause damage. Therefor optimax you should either idle, or run at higher r.p.m. They may have fixed this on newer model optimax's I'm not to sure. Anyway i just thought i would throw that in there so you know why he said that.