Hi Guys I need some help.

1st question is: what is a good base tuning setting for the Sirio XXX & XXXV being top, bottom & midrange settings?

2nd thing, I have two XXXV's and cannot get them to idle consistantly, could this be due to worn conrods?? both engines have had around 30 tanks through them, around 2.5 litres of fuel (I would have thought the rods would have lasted a bit longer than this from new) What do you suggest???

3rd thing, when I get the engines to what I believe is a pretty good tune, inclusive of a clean bottom end idle, the motor dies at the end of the main straight (50-60m long) from WOT. Basically what happens is that the motor runs OK for 2 minutes or so and then at the end of the main straight when you throttle off for the bend the engine just dies!
Is this a "too lean on the bottom issue"
Just in case you suggest it, I have made sure the idle is not too low.(in fact I make sure it's a little bit high to compensate for this problem)

I've tried richening up the bottom end but then the engine will not idle well. To be honest I'm stumped! I've been racing for over 10 years so I know a little bit about engines but these Sirios are just too hard to tune and keep going!
Yes, they are cheap but that means nothing when you loose confidence in the tune

Help anyone!!!!