Hi all I have,a optimus 99 stove its been in use for many years . But now will not light and burn properly I suspect it's the wick needs replacing . I have watched the renewing on an 8r in this forum using the cotton from a mop head . I plan to try the fix but wondered if anyone had any more advice on the subject . Many thanks Carl .
I agree with @Paul Lydon regarding the seals on the tank cap. The 8R types like this and the clones are bulletproof "IF" the tank filler cap seal is bad or the SRV pip is bad. The tank will not build up pressure and the stove will operate poorly. The only reason I would change the wick would be if old fuel was let to sit (like for years) and the fuel has broken down into sticky gummy mess. When the seals are good you should be able with the warmth of your hands get fuel to start coming out.
A dunk test is a good start. Close it all up. Put the stove, without case, in a freezer. Open and then close filler cap. Dunk in hot water. Report where you see bubbles.
@snwcmpr now what sorcery is this? Thats a test i never heard about...ill have to give that one a try!
No I have not replaced anything yet . When I prime the stove prior to lighting it will try a little to fire but only just . However the tank is building pressure I can hear the sound when I remove the cap . Replacing the cap seal and pip would be a good thing to do I guess after all its very old and I've never changed them . Do you have any idea where they are available ? Many thanks carl
I would dunk before you just change the seal. Knowing what you are fixing and why is a good idea. That way you dunk after repair and verify you fixed something. Wicks can get bad. Dunk first. Are you using Coleman Fuel (or whatever is used over there?)
No I'm using unleaded petrol ,I have ordered the seals already but I will do the dunk test first before I start the fettling . Thank you for all the good advice . Regards Carl
@Etz250 I would stay clear of unleaded petrol in your Optimus 99, except in dire need. You should use a pure gasoline (naphtha) — commercially sold as Coleman fuel and similar. In the UK, folks around here recommend the naphtha-based Holts Brake Cleaner (not the one that’s water based). Best regards Tony
@Etz250 , Carl, I agree with Tony, regarding steering clear of Unleaded auto fuel, and also join those who recommend you do the dunk test first, then change anything. The 99 is a neat little stove, and with proper care and maintenance, it can last several lifetimes, and give excellent service. Good luck, and let us know how things go. Take care, and God Bless! Every Good Wish, Doc
From how I understand your comment above either you haven't closed the valve completely during priming, or the pricker needs to be adjusted to close the jet completely when the knob is in its Off position. All other diagnostic and maintenance procedures already mentioned should be followed, too. The stove valve needs to be turned to Off completely while the priming flame is burning. When the flame just starts to recede, the valve is opened and the stove should light; otherwise, prime the stove and when the priming flame goes out, open the valve until you hear a slight hiss and light her up. When the flame settles down, open the valve more.
