Dear friends, Last night I bought an old Optimus 00 which had not seen much use in decades. Having inspected and oiled the pump leather I quickly realised to my disappointment that the NRV was not working, as no air made its way into the tank, even when pumping hard. I have restored a couple of newly acquired kero stoves lately, a 1930s Radius 21 and a Høvik Verk 2Pt Primus with great results, so I thought the Op.00 would be a suitable addition to my collection. That said, I have never had to replace the NRV, and had to improvise the NRV wrench/tool. I was a little apprehensive about undertaking the removal and dismantling of the NRV, but thanks to the various members of CCS who have written eminent posts about NRV removal and repair, I felt moderately confident that I was up to the challenge. I took a standard hex driver and filed an opening to fit the NRV (see picture), feeling my way to the right size until the fit was snug. The NRV came out ok, and with some solvent oil spray I was able to take it apart after five minutes of soaking. The rubber pip seemed ok once it came unstuck, so I merely elongated the spring a little and put the NRV back together, guided by my memory of CCS posts I had read in the past. With the pump and NRV restored, I proceded to do a test burn, which was less than successful. Fuel was leaking from both underneath and above the spirit cup, and no in-situ tightening of the burner head would fix the leak. Having taken the burner head apart, cleaned both gaskets and screwed the burner head firmly back together using two wrenches, I screwd the burner back onto the tank using only hand force, and voila - successful leak-free burn at maximum pressure, and with a flawless flame pattern indicating a nozzle in good working condition. I then cleaned and polished the tank, and I must say I am quite happy with the result. I also found a 1 litre British Army utility pouch that just about holds the entire kit including an 80ml spirit bottle and tools, so I am pretty sure this will be the stove I am taking camping this weekend. I will add the pictures below. What do you think? Wishing everyone a pleasant weekend! T
Great you got it running. I usually try poking the NRV with some wire first if stuck, may need to eventually replace the pip. The burner on these uses just a small lead washer to seal the burner to the fount. I only replace the gaskets if they leak. Seems the gaskets seal best if only hand tightened, I've tried a few different ways, wrenching usually makes a leak worse, that's why I hate to replace gaskets. Duane
those are great stoves and congratulations on the repair. I would pick up a rebuild kit from the Fettle Box, it will have all the seals and parts to make it last another 50 years.
Thanks for your comments guys. I can report that the stove performed well during this weekend’s overnight in the woods. Nice weather, but I was sleeping at 320m altitude, so in the wee hours it was a chilly minus 5 Celsius, and while it made sleeping a bit difficult, it made it all the more tempting to fire up the stove and cook an early breakfast.
