No no no no no no no NO one last time it is categorically not OK to just stick the HRC card in and cross your fingers, nor is it OK to change anything else and just hope for the best.
The HRC card advances the timing and will allow more load to be placed on the engine, detonation is more likely with it than without it.
The stock '28 jetting is Honda's safe setting for all conditions so somewhere in the world that my well be the correct jetting for an HRC card or maybe even pipes etc. the whole shbang, elsewhere it may be quite close to the edge anyway.
Re. cgallant changed his '21 pipes and it ran fine for 6 months on standard jets, Dave Ett tried the same trick and got about 2 miles up the road.............
Today at apex fetching the '28 back even jo wouldn't say for sure that my jetting was right, she said it should be "very safe" (very rich then) but she did visably flinch when I said how I seized it last time (flat on the stop in 6th!) and advised I try to aviod that situation in the first place.
_________________
Please do not PM me technical questions, if you can't find it on the Forum start a thread