Hi everyone, I recently bought an Optimus 111b through ebay and upon receiving it, I fired it up and it was running inconsistently. Figuring that it hadn't been used in a while, I bought a parts kit through eBay and replaced the nipple, needle, NRV valve, and lead/graphite gasket that attaches to the spindle. Despite the new parts, the stove still runs sporadically. It flares up (yellow flame) then dies down (blue flame) almost rhythmically for a time before it eventually sticks to a blue flame. However, once it sticks to a blue flame, it runs for about 5-7 minutes before it dies out. I'm a new member, and I've read extensively through these threads (and the rest of the internet) trying to figure out why this is happening. Once the flame burns out, it's still retaining pressure, so I'm certain it's not the gaskets/valves. I've cleaned out the fuel filter thinking that maybe it was dirty and there was an obstruction, but still the problem persists. The only observation that I've noted is that actual liquid fuel shoots up through the nipple after a while when the stove has been primed. I don't know if this is normal, but I'm assuming it is not. The reason I say this is because when the stove is running properly (blue, loud flame) before it goes out, I cannot see any liquid fuel coming out of the nipple. I'm assuming the stove is not vaporizing the fuel properly, but I cannot figure out why. I've tried everything I've come across on this great site and the internet in general, but I'm still at a loss. This is a great stove--and it's operation is so simple!--but I still cannot figure out what the problem is. Any insight or suggestions is very appreciated! Thanks in advance! 508
Welcome to CCS 508, Liquid fuel shooting up is never good. Usually Coleman fuel vaporizes easily. Are you using any additional windscreen around the stove besides the burner windscreen? Cape Cod can get breezy this time of year. You may need an additional preheat too on a windy day. When you say it runs 5-7 minutes then dies out it could be a pressure loss. Have you checked the fill cap for leaks? Pump it up without lighting and spray some soapy water around the cap. Pull the pump rod out and spray down there too. Leaks show as bubbles. A picture would be helpful too. Ray
I'll try the soap test tomorrow (before the snow!) although I think the seals are all good. When it goes out, I can still hear it hissing from the retained pressure within. I figured seeing actual liquid fuel coming up from the nipple wasn't a good thing, thanks for confirming It's been cold here, so it might be that I'm not priming for long enough with these temperatures. If the burner assembly is real hot, will it vaporize the fuel as it comes through the nipple? I apologize if these questions seem elementary, I'm still learning the in's and out's of these style stoves! I'll post results and pictures tomorrow. Thanks again, Ray! 508
Does the pump rod rise after you pump the tank? That would be something to avoid, gas coming up the pump tube. Yo do not mention replacing the filler cap gasket. Ray is right about the leak test. If the soapy water doesn't reveal a leak, pull the tank and burner off of the box and dunk in a tank of hot water. If no bubbles, open the valve and dunk to see a steady stream of bubbles from the nipple. Then, when ready to light it again, try opening up the valve more slowly before going full open. That may allow the vaporizer to get hotter before full open. Welcome to CCS
Yes, if the burner is hot the fuel leaves the jet as vapor. After reading the first post I thought the stove was running 5-7 minutes then the flame began to die out. I would think slow pressure loss in that case. Now with the 2nd post it's running and then the flame goes out suddenly but there's still pressure? Can you relight at this point? Maybe it's dirt working it's way out. Was the tank clean? You have to expect anything with old stoves that haven't been fired up for awhile. Shake the tank then empty the fuel into a jar and have a look at it. Dirt and water if present will settle out and you'll see it easily. Did you install the cleaning needle using the procedure outlined here on the site? When our European members wake they'll probably have some more ideas. My basic starting procedure to get an old stove running is clean the tank, oil the pump leather, make sure it pumps air into the tank and holds pressure. Since the 111B runs on white gas it's important to ensure the non return valve at the bottom of the pump tube doesn't leak. You say you've replaced this? Ray
G'day 508 and welcome, What fuel are you using? As Ray mentioned these stoves are designed to run on White gas / Coleman fuel. I seem to remember similar problems mentioned using Kerosene in cold weather.
The 111B is only for gas, Coleman Fuel, petrol, or what your country calls gasoline. Kerosene will not vaporize well in the 2 tubes of the 111B burner. The regular, kerosene, 111 has 4 tubes for more efficient vaporization of kerosene.
Hi, i don't know how many Op.111b references you found on CCS but these might be useful: https://classiccampstoves.com/threads/optimus-111b-problem.29623/#post-302296 https://classiccampstoves.com/threads/111b-symptoms.9830/#post-95410 Best Regards, Kerophile.
Thanks for the information everyone! I've been using Coleman Fuel in the 111b. Ray123, I replaced the nipple, needle, NRV valve, and lead ring on the spindle. I broke it down this morning and did the water test. I emptied the tank, pumped it up real good and submerged it in a small bucket of water. It was leaking real good from around the nipple/jet and up through the fuel hole itself. I did replace the nipple when I got the new parts kit (the old one was starting to mushroom on the top from the wrench slipping off it too many times) but I think I'm going to put the original back on and crank it down real tight. After reading through the links kerpohile provided (thank you) I might have the wrong jet on there and it also might not be tight enough Will be back with updates this afternoon. Thanks again y'all!
Original nipple/jet has been put back on (tight!) and I did the water test again. The only leak under pressure is coming up through the nipple. The regulator is all the way in the "closed" position. I imagine there shouldn't be ANY leaks when the stove is closed but to my knowledge, there's no gaskets or seals inside the burner assembly, it's just the needle sitting in the shaft with the spindle down at the bottom.
If leak through jet/nipple when regulator is 'Close' I guess the needle is set a bit to log? In that way; needle prevents the regulator to close completely. Wait for comments from other (more experienced stovies than me) before you act. If jet/nipple is easy to remove and put back; try to run burner without needle. If it then is possible to close, you got the answer.
508, Don't crank the jet in too tight. You can damage the jet seat and then you could have real trouble. Any leaks around the jet result in flame. Usually a small candle size flame. If you have bubbles coming from the jet in a leak test it's either the cleaning needle is set wrong and not allowing the valve to close or the spindle tip is a little worn and not sealing completely. Not related to your original problem in my opinion. Hi Ivar, you were a minute quicker than me on this.
That is the good thing with NCC @Ray123 - if having an issue; you will get response. And we learn. Let us see what @508Moniz finds out.
IvarS and Ray123, you nailed it on the head! I pulled the needle from the fuel shaft and compared it to the old one. It was a tooth too long, perhaps a millimeter. So I ground it down, reinstalled it, and tried the water test again...no bubbles! That one tiny section of tooth was just enough that it was hitting the bottom of the shaft, therefore not allowing the spindle to sit properly and close. I just had it going for about 10 minutes a while ago, nice even flame from all sides of the burner. While it might not have been related to my original issue, that great info certainly fixed it! I'll try to get some pictures of it a little later when it's not so bright and sunny out. Thank you guys again so much! I've been fighting with this on my free time for weeks and it feels so great to finally have solved the mystery 508
(psst... @508Moniz; I can tell you; most of the Gents here do like to see a few pics. They have seen pictures of all kind of stoves before, but still love it. I Guess it is either passion or addiction.)
As promised, here's some pictures and a video of my 111B in action. I can't stress enough how good it feels to finally have this baby up and running properly. A friend of mine introduced me to this stove and I decided I had to have one. After so many trial and errors, I was beginning to get discouraged, but thanks to Ray123 and kerophile, that dismay has been vaporized into stove joy! :o Hope you all enjoy the pics and thank you all again so much for the advice/insight! 508
