I’ve just bought an Optimus 111c from a local market. It wasn’t super cheap but seemed to be in overall decent condition so thought I’d take the risk. I removed the pump shaft to check the condition of the It’s a lot younger than my other stoves so I’m tempted to move it on but I’d ideally like to get it going first.
I’m so sorry I must have accidentally deleted it! I meant to write that I opened it up to check the condition of the pump leather
As far as I can tell from studying the parts and other posts further it seems like Optimus international may have opted for an inferior fixed pump leather rather than a floating one during this period. This would mean that the leather was simply fixed in place by sandwiching it between two washers. It seems that if I’m correct whoever last worked on the stove may have put one washer that was to big in meaning that it didn’t hold the leather in place. I’ve replaced the washer with a smaller one and it does tentatively seem to be pressuring now. it’s a shame the engineering really doesn’t seem to be up to that standard of older Optimus stoves.
My guess, the original pump was Oring, not the leather as on your pump. Maybe purchase one of these. https://www.ebay.com.au/itm/2366446...oUeJi45y8|tkp:Bk9SR7yCvor2Zw&var=537157548847
Some old guys still make many replicated parts for stoves and lanterns in Korea, I think this business will not continue after 10-15 years from now. they are too old, it's pity.
Looks like the pump on my Optimus nova. I just loosened the nut a little so the big washer can wiggle a little, otherwise it felt like I was like trying to suck the malt chucks up through the straw in a milkshake every time I pulled the handle back. You could machine off a little more so the nut will actually fit on properly and put a matching chamfer on the washer to work sort of like a real one. Either that or make a oring holder for it. I bet that the nrv pip is not the brass cup type as well. What is the burner?
Thank you all for the advice. I think the pump set up may be original after all but as others have said just not as good as earlier 111 models. The pump does seem to work now albeit in a less efficient way. I got the stove lit however the elation was brief as on the second light it wouldn’t get up to power. It turned out the self pricking needle had broken off in the jet! Once this was remove it fires up nicely. I just need to order a replacement from The Basecamp. all in all I think I will probably move the stove on before long.
@optiben80 I was working on an Optimus Nova this evening with the same pump setup as yours. I would not pump air and when pulling on the plunger it would create a vacuum and no air was getting around the pump cup. Also, the washer under the nut was too large and would not let the new pump leather into the pump tube so I took it out and it works fine. On new Optimus pumps the washer is only slightly larger than the nut.
