thanks guys for all the support and advice. problem is now fixed. looking at the shooter it was slightly off centre to the ball so I tightened the interior nuts and it now works 100% of the time.

Thansk everyone for all the advice. I know I ask stupid questions from time to time on here and aussie arcade but my skills with this stuff are VERY limited and I just learn from the net, forums or pay someone to fix it!

Cheers
Johno