I'm working on a build using an ST4S engine (996) and whilst getting the engine checked over (never heard it run before) my engine guys have found it is binding somehow due to the primary gear. Has anyone come across this before ? It appears the gear behind the clutch basket has been modified (lightened) and maybe isn't even the correct part. The Gears are overlapping not directly engaging which doesn't seem correct either (?) The engine rotates freely until the clutch basket is tightened down at which point it locks up If anyone can shed some light on this I would really appreciate it ! Even some photos showing the correct engagement of the teeth would be helpful at this stage to see if what we have is correct or not Any help very welcome - thanks !
The primary gears are supplied as a matched pair. Crank and clutch gear. If one has been swapped, then there's a chance that's the issue. With the engine locking when the clutch is tightened up, I'd check the two bearings in the gear itself. #20 & #18 are in good order as well.
Thanks Nelly, will pass that on Have just ordered a 2nd hand Primary set (un modified) to see if we can work this out further
Just to update this, a replacement second hand primary set resolved this, will post up pictures of what was fitted originally to see if it can be identified...
