If your fuel doesn't want to work, you can probably add some fresh ether and it will be fine. The castor oil and the kerosene don't evaporate but the ether will. So additn some ether back in should make it work.

Thanks for the recommendation Richard!

@@kuehn1953 To really get "into the weeds" there is a top article at Adrians Model Aero Engines. I can't put in a link but the name is 'Fuels for variable-compression diesels' and I find it by searching for 'adrians model engines diesel fuel'. 40 30 30 is a simple improvement on "equal parts" but Adrian really gets into the optimisation. Where I live we can't easily buy ether but we have someone who is licensed and he sells us premixed diesel fuel with ignition improvers and all.

@@RichardTapp1 I've also used 40/30/30 to good effect, and replaced the castor oil with regular 20w50 as it cleans off easier IMO. The kerosene can be replaced with regular automotive diesel oil, and some sources say that the lube content can be reduced a few percentage points when this is done. I can't say I've noticed any difference. I had learned that diesel engines can be run (but won't start) with 0 ether content. Without ether, the compression needs to be increased but it runs just as well. 20w50 needs to be used because castor oil won't mix with kerosene without the ether. I partially filled the tank with regular fuel, enough to start the engine, and once it was warmed up and happy, I'd top off the tank with the etherless and retune. Ether was expensive, especially on a schoolboy's allowance.

You must be in the UK or Europe. In the USA ordinary citizens can't buy ether. Starting fluid is the only option

@kuehn1953 That's a bummer. I'm in Cape Town South Africa. Have a great day. 👍