I just restored to life a Russian clone of the Optimus 8R. It runs fine, but the flame has yellow tips (see photos). What could be the cause? I am using unleaded car gasoline (white gas is not available here.) The same fuel burns in clean blue flame in my Optimus 80, so this is not the cause. The valve chamber with the cleaning needle is clean, and free of any gum. I do notice that the fuel flow is a bit restricted - warming the tank with my hands does not cause fuel to drip from the nozzle. However i do get high roaring flame as soon as the stove heats up.
Hi, with the yellow flames, the mixture looks to be slightly fuel-rich, which might suggest a slighty enlarged nipple. However, once a pan is in place the flame looks good. I would be inclined to use it "as is" rather than chasing the perfect blue flame. Just my penny-worth. Best Regards, Kerophile.
Hi, A few years back I bought one of these (new) from A&H and they accually recommeded unleaded gasoline. I tried it and also got yellow tips (and a bad smell), I switched to Coleman fuel and the problem went away. Not all gasoline is the same of course, so yours might indeed be cleaner burning, but I would suspect the fuel. The flame looks pretty good when the pot is on. I notice a nice brass handle, is that your work?
Thanks for the advice. Indeed, if I wanted to take the stove in my backpack next week, I would be quite happy with it the way it is. However, as a collector and a perfectionist, I see a welcome challenge in trying to get the stove to "perfect" condition. I will keep experimenting, and will post the results. The brass handle is indeed my handiwork - the handle that came with the stove was so rusted that I preferred to put it away. :-)
Looking at the pictures you posted, perhaps your flame spreader is a bit low, try bending the arms to raise it a little bit higher by about a millimeter. It might do a bit better in the fuel/air burn mixture. Ron
Ron, It works. I raised the flame spreader, and now I have a nice clean flame. Will post photos later.
Here are some photos showing the repair. The flame spreader "before": The raised flame spreader: And the way it burns now:
What a great 'fix'. I thought it might have been a fuel issue as well. My clone is similar so I will be following up with this idea. Ian
Wow really made a big difference! That is good to know. Looks like you are also using a pump Yonadav?
Nice work!!! I am starting to get curious about this little Russian clones/look a like. I will have to add it to the list.... the long one Cheers, Jeff
Hey Gary, well, the flame spreader caught my eye to be a bit low and am glad he only had to raise the plate a bit to get the lovely blues. I learn good from the master himself (Gary san) Ron
I have one of these stoves and havn't got round to playing with it yet, but this thread made me take a look at it. Sure enough the spreader plate sits low, just the same. So I will be trying this fix. And seeing those photos of it burning gives me the motivation
John, No, I'm not using a pump. I get this nice roaring flame with the stove's heat pressure only. Funny, but I have a feeling that the fuel flow is not really free, as I cannot get the stove to drip some fuel out of the nozzle by hand-warming the cold tank. I do have to use a fair amount of spirit to start it. Yonadav
