which turned out to be from the solenoid connection to the battery. I unbolted the leads which were tight enough and the connectors plating was black but didn't look too bad, anyhow I cleaned up both sets with some emery and the studs with a wire brush, annointed with WD40 & reconnected, on pushing down the starter lever just to see if it had made any difference I was pleasantly surprised when she turned over perhaps 50% faster and roared into life without cold start 
yup main problem had been sluggish turnover speed all along 
Thinking I probably had wasted the £2.99 spent on a bottle of injector cleaner just poured into the tank - I hitched up the trailer and toddled off into the wood to drop and cord a couple of badly leaning Silver Birches during which time she was just ticking over, a 'music' which I have enjoyed for over 50 years
now it may have been the after effects of the chainsaw on my ears but while I was loading up driving back and unloading the exhaust sound seemed to have changed slightly, I think that there may actually have been some effect from the cleaner - praps I should have a closer look at that 'engine rebuild in a bottle' stuff I saw advertised in one of the comics 
Anyhow, if you have starting issues it might be worth having a look at the heavy current connections even if they look OK at a casual glance
