Finally found an Optimus 99 and just fired it up today. I noticed that you cannot turn it fully off. Even with the key tight to the right fuel comes out of the jet as pressure builds during preheating. It burned okay with a slightly greenish blue flame with not much adjustment ability. Had to turn it off by turning it fully to the left to get the jet cleaner to come up otherwise it just keeps burning. Once "off" and back to the right the fuel continued to seem from the burner until the priming pan was full and I had to open the fuel cap to release the pressure and stop the leaking. I did try removing the jet but it is very firmly in place and I could not budge it. So......where do I start on this one and what little bits might I need to service this stove? Never had a self cleaner apart before.
Sounds like the cleaning needle is off by a tooth. If you could get the jet off you could check that, but, you can't. Hmmmm. Is the burner all gummed up or does it have some defect? sam
The burner does not look very gummed up at all. The jet just seems extremely tight. I will try and work with it more during the week.
Okay, just checked it again. I have almost a half turn between right and left stops with the key. When fully left the cleaning needle projects maybe 1/8" through the jet. Tried the jet again and it is really stuck.
I had the same symptoms on my Svea 123r. It didn't help removing the cleaning needle. I had to replace the spindle to get it working.
Hi, I fear afoton may be correct. Generally with these stoves you only get around one-third of a turn from fully closed to cleaning needle raised. You have more than that with your "almost half a turn" so a poorly inserted needle preventing the needle valve from closing is unlikely to be the problem. Heavy-handed use of the regulator, in the past, could have damaged the tapered faces of the needle valve, preventing total closure, and the symtoms you describe. Either way, you need to extract the jet before attempting removal of the cleaning needle and reguator spindle. Best Regards, Kerophile.
I agree, but thought that the removal of the needle would eliminate that simple solution from the possibilities. Ken in NC
Thanks everyone. I was guessing a damaged regulator taper as well since I do have full movement of the cleaning needle (the link to the service instructions was very helpful). I see no way I am going to remove the jet with my tool. Mine is a NRV tool which I think is the same size tool for the jets correct? It is a close fit but not enough to prevent it from slipping off no matter how hard I press it down onto the top of the jet. I stopped before damaging the jet but not sure where to go next with this.
Hi, here is a suggestion: 1. Unscrew the burner bell/ flame- plate to expose the jet. 2. Obtain a good quality adjustable wrench to grip the jet flats. 3. Grip tank firmly. 4. Turn jet anti-clockwise. Best Regards, Kerophile.
Kerophile, sounds like a good plan. I have a really good quality one with no free play in the jaw and will try that.
I am in the presence of experts and agree with all of the above....remove burner bell and heat the brass just below the jet with a pencil torch immediately before attempting more wrenching. A bit of thermal expansion often releases these easily. Please take care with the surrounding flammable fuel... May the Force be with you! B
I used a large, well made adjustable wrench and got the jet removed without damage. Played around with the needle, examined the spindle and the tapered face looks perfect. Put it all back together, snugged up the fuel cap and got fuel coming out of the jet still. Tomorrow I will remove the needle and assemble without it just to see if it is preventing the spindle from seating properly. if so at least I know what to work on. I don't fully understand the reassembly and just how the needle is supposed to sit in relation to the teeth vs. spindle "gear".
Hi, different burner, but a regulated one, and the principle is the same: https://classiccampstoves.com/threads/regulated-burner-cutaway.15697/ Best Regards, Kerophile.
Great photos! I guess what I did not understand was the setting the of the needle and the 5 click thing, not so much the relationship between spindle and needle. Poor wording on my part. I did just find a good thread on here about setting the cleaning needle on an 8R which I will try as I fear I have the needle a tooth or two off, preventing the spindle from seating all the way. I will give it a try without the needle first to be positive that it is not the seat/spindle. So glad I found this forum and thankful for all the help with my probably repetitive questions. I try the search function but sometimes by not using the correct terminology I do not find the answer I am after. Thank you all for your patience with this newbie !
Has some time today so removed the cleaning needle completely and fired the stove. It still leaks from the jet just like before. I did have the spindle out and the needle cone looks nice with no damage or grooves so now I am stumped. While the stove does run and work with this flaw it would be nice if everything was in perfect order and it would shut off without me having to blow out the flame. Of all my stoves this is the one I had hoped would be my regular user as I just like the idea of a built in lid/pot.
Hi, sorry that you have this problem. The good news is that you have localised the problem to the needle valve of your Op.99. The bad news is that it doesn't seem to be a fault in the regulator cone (which is replaceable), but in the matching seating in the burner. If you can find a burner assembly for an Op.99 it is likely going to be expensive. The traditional way of checking the match of cone and seating of a needle valve is to ensure the valve is dry and fuel-free, then to coat the cone with "engineers blue" or magic marker. Once dry, screw in the cone fully, then remove it and see if you have a continuous ring around the cone. If you don't it confirms your leak diagnosis. Again, in an ideal World, you have a thread-free cone, which you coat with grinding paste, then rotate inside the seating until you achieve a matching seal. I do not know how you can manage that with a screw-in regulator. Perhaps one of our CCS Engineers can suggest a solution. Best Regards, Kerophile
I will try the bluing and see what it shows me. If I still owned a lathe I could make a steel shaft, tapered like the spindle and just large enough to ride in the threads but not threaded and grind it as you say but in the downsizing many years ago I sold my small lathe off to a gunsmith. At least the stove will work, makes a fair enough flame for cooking and all I have to do is blow it out when done like a candle! Maybe I will find another one day when the prices are no so high. Thank you for your help
