Roundhouse valve setting

[Yorkie59]

Hello
I am a newby to 16mm as well as this forum so apologies in advance if my questions are answered elsewhere. I recently built a Roundhouse Lady Anne from one of their excellent kits and added a Summerlands Chuffer at build stage. Everything seemed to go ok the loco ran, I thought well. However there was no chuff, it was very quiet.
I had decided that the valve timing must be out when I noticed that water was leaking from superheater/valve junction. As tightening did not cure leak I contacted Roundhouse who suggested that the tee piece nuts were being over tightened and seals damaged. On checking this was the case and new o rings ordered.
Once new seals are fitted the valve timing will have to be redone.
Whilst the RH instructions are clear no mention is made of how to allow for end play at the valve which is about half a port when setting timing in forward and reverse.
Can anyone advise on this please? These locos are very tolerant but I would like the chuff seen and heard on numerous video's.
Peter

[tom_tom_go]

Have you managed to get the timing sorted?