Thank you Oilman and Mandate. all good info.
Just what i needed.
I can confirm that the nozzle is 80 degree @3.78 litres per hour rated.
I did not put a pressure gauge on as i could see from the spray and the pump internals that there was low pressure due to wear and tear. (used to oil pumps on American V8's.) Hindsight just kicked in.
I seem to have struck lucky with the reassembly as i have the swirl plate clamp slid all the way up to the end of the nozzle tube which gives a nozzle tip to swirl edge of approx 6mm and the ends of the spark rods are level with the nozzle tip with a gap of approx 1/4".
I use homeglow 35 gas oil but when the problems started i did have the oil co deliver a lower quantity of oil and added some kerosene to thin the lot out which helped it burn better??
I have a few spares which is handy. I make a point of doing that due to previous problems with cars. I have a spare spray assembly which has a cast swirl plate which does not seem to work as well as the pressed steel vaned version. I have not yet used a new nozzle as i keep one spare which i dissamble and clean out with fuse wire and keep in its little plastic box as a just in case item.
I do clean out the heat box each year of all that shale.
At the moment it is thermostat timed heat controled for 8 hours a day and seems to fire up for only half of that time because of its internal stat and room stat combo. The rest of the day it switches to freeze/min temp setting to protect the pipes etc.
uses 2500 litres of oil a year give or take a few but boy the price has gone up 100%
I have 3 differant models of electronic control units as back up and a spare motor/blower assembly.
Knowing my luck i have enough bits to see me out but it will go and pop a rust hole at the lowest point in the boiler case and i will end up having to renew.
You mention the adjustment nuts at the top of the assembly. Thats one of the places i would like to know the initial trial setting for the ammount of protrusion into the boiler heat box.? That must make a differance to the performance once you get to the analyzer stage.
Just in case it helps you guys. I picked up a sheet of heat/flame proof insulation material 1000 x 600 and approx 10mm thick when at the trade depot.
Its white and brittle, cuts with a stanley knife.
I cut two pieces, one smaller than the other and these fitted into the front cover. I put two layers of cooking foil over the face of the larger one which was closest to flame.
They are held in place by the cover when bolted into place by the 4 bolts.
You can put your hand on the cover whilst peering in to the view hole without losing any skin.
Hope this helps in some small way to repay your help.
Happy Days,
Chris.