907 Problem update

[Timbo]

Dear Pasoists
Many apologies for not keeping you updated with ongoing saga (posted 24/09/06)
I managed to remove valve head from horizontal cylinder and found piston fine but problem being exhaust valve not seating properly and burnt hence low pressure.This both valves were reground and new shims fitted when replaced still not running right.
Problems starting which in turn is flattening battery.
Will start after time on fully charged battery( new and correct size fitted )
Runs perfect when starts,but when turn off and try to restart wont and seems to be kick back at sprag bearing.
As of Saturday Ive give up in my efforts to find problem,now in hands of Very good resonably priced Ducati mechanic.
My friends tell me I should let her go but...............
Ill let you know
Cheers Timbo
Timbo

[Rogero]

Very good reasonably priced - WHERE please!!!

[mikeakageoff]

I'd quite like to know the contact details of the mechanic also please.

Mike
(also on the wirral)

[Timbo]

Rogero,Mike,thanks for replies sorry for delay but busy in work.Contact me via Private Messages and I let you know.
Timbo

[Rogero]

Will do Timbo.

I'll liase with mike too!

[cagiva905]

This is not a difficult problem:

Because the valves were regrind, compression has improved, which gives a greater load on the starter motor and the starter clutch. So only now you find out the clutch is too worn.

I had the same problem after a complete rebuild, had to replace the clutch afterwards.

Michiel

[Finnpaso]

I think, its very good idea to measure compression pressures every 30 000kms, or so.... When i lost my valve seats in previous 907 sylinder heads, another cylinder had only 20% compared to another one.... :laugh: :laugh: :laugh: It was easy to start cold, but after warmed, then HORRIBLE.... :thumbdown:

[Timbo]

Annti,Michiel
Thanks for replies,when I did the pressure tests on cylinders the horizontal one with (worn valve) was showing around 80 PSI yet the vertical cylinder was reading 140. Horizontal after service reading 150( valve re ground shimmed etc !)
The Haynes manual all be it not exact for 907 gives guide as follows
Standard 130-160 PSI (9-11 bar)
Minimum 116 (8 bar)
Maximum difference between cylinders 29 PSI (2 bar).
Thanks
Timbo