Tomorrow I will take the head with me back into town and see if I can get him to accurately measure the guides and I am looking at getting some over sized valves made, this may be the simplest and easiest way to go.
Having endured the day without power because they replaced a transformer down the bottom of the street I could not do the jobs I wanted to do but did get to shuffle a heap of curtaining fabric around in Dee's work room. So when I finally got to play mode I had a go at removing the needle from the stem after being in the electrolysis tank for a couple of days. It did come out sparkling clean but obviously still a lot of carbon on the inside. I have easy access to the bottom of the needle via a hole where the fuel would run into the cup, also can get a good hold on the top of the needle but it is not budging yet.
In the McDonald hand book of instructions it does mention a few times to use 'kero' to clean the fuel system parts in. Why this is suggested rather than clean diesel is a mystery to me. So it is soaking in some kero at the moment. I am also now eyeing up my ultrasonic tank as I can actually touch it now some fabric is gone. so find a plastic jar and some petrol and spark it up, literally not physically.