the red devil

Thanks for the advice, guys. I think you might be right that it's restricted – hey, look on the bright side. At least the engine hasn't been overstressed!

I found another thread explaining how to do a physical check for washer-based restriction, but it also mentioned 'different sliders'. I have no idea what this means (not mechanically gifted...). Anyone able to explain?

(And the bike's carbed, so you're right, no ECU.)