I have a 2005 620ie with ATPC and a 2004 999 without and have one heck of time adjusting from the 620ie to the 999. The main difference is how late the 620ie's clutch engages. I have researched on the forums here and things like heavier springs (what models would work?) and/or a Oberon slave cylinder could help. Are these options still valid or are they others like a better master cylinder? I also read that replacing the whole clutch with a non-ATPC version is a solution, but I would like to avoid that one if possible.
Has anyone else with an ATPC model with this symptom made a modification to fix this? Any suggestions would be greatly appreciated!! [thumbsup]
I'm not sure the spring replacement is an option for the APTC. I swapped in a non-APTC and was happy... I think the replacement engine is happily non-APTC also. I haven't taken it apart to check, though.
It is my impression that the APTC engagement is always kind of vague, no matter what other things change.
I know exactly what you mean (M695 + 749s here). The "friction zone" of the APTC is very narrow and the stock engagement is kinda weird. Plus the super light touch. Adjustable levers can help with the engagement position. Just be sure to get the free play correct after install. Levers would be the cheapest/easiest "fix" and might be all you need.
BK
Larger slave cylinder will widen the engagement range.
But the lever effort is really light already, you may end up with insufficient feedback to modulate the engagement.
Perhaps some tuning of the clutch on the 999 to tighten up it's engagement range?
I decided to try an adjustable clutch lever and found that it does help. I am still in the "adjustment" period yet I do feel an improvement. My thanks to all that offered me advice! [clap]