I had a couple redhead 700's that had the brass gear slip when hot and a srx also. In all of those recent cases, I could NOT spin the gear even when heated up with a torch and grabbed it with vice grips(knew i was changing it so damage didnt matter to me). Had the cranks repaired and no more cooling problems, i think the load the impellar sees is more then you think especially at 8500rpm.
If your impellar is that tight on the shaft, its likely not slipping, I have only had 1 in all the years have the splines chewed out and it was loose as a goose on the shaft. With it being that tight, its the gear thats causing the trouble...............which sorry to say, means you need the crank redone or another bottomend to replace it with.
If your impellar is that tight on the shaft, its likely not slipping, I have only had 1 in all the years have the splines chewed out and it was loose as a goose on the shaft. With it being that tight, its the gear thats causing the trouble...............which sorry to say, means you need the crank redone or another bottomend to replace it with.