Well Im disappointed. Put the stock secondary spring back in with the 46 helix. Would hit 8000 max but mostly down to 7800 even down to 7600 when loading it hard in deep pow. Swapped my secondary with Wyoboys. He has the stock 48 and a 200-280 spring in. Boom would hit 8100-8150 and down to 7900 min. Cant believe that worked better at 11,500 ft.
I was running new NGK plug caps and different plug wire too
I think you cat guys wanna see constant 8000+ when on full throttle to that 858 engine run properly. If it drops to 7900, its not backshifting properly. Helix is too steep or spring is too soft.
I would suggest that you try 42 straight helix with that stock secondary spring. Or rather 140/260 or 160/260.
Or if you wanna use stock 48 helix, go with really stiff, around 200/320+ spring.
If you want that 46 helix to work, go at least with 180/300.
What people need to undertand, is that is not just the rpm. With steep helixes like 46 or higher, secondary will load the engine way more. Yes, you get that feeling of "strong pull" and hard track response right from the beginning. But with high load, also comes slow throttle (engine) response. Engine will feel sluggish.
2-stroke engines, especially non turbos, have very thin torque curve. They dont work the best under high load. Just like gas engines on cars, you ride them with high rpm and on diesels you run them with torque (short shifting).