Hi guys, I have a Primus No96 I haven't lit in a few years. I ended up lighting it today and noticed after a little bit that fuel was slowly seeping out of the pressure pump. Does anyone know what causes this? After I shut down the stove, I unthreaded the rod to inspect the chamber and noticed a little puddle of fuel inside the chamber as well. Is this normal? What can be done to repair this? Finally, How does this flame look? Anything that I can do to improve it?
@mpr86 Your fuel non return valve (NRV) at the bottom of the pump tube is leaking, allowing fuel to back up into the pump tube. If you are lucky, and it's because of a bit of grit, you can fix this by half filling the pump tube with kerosene and pushing it back into the tank with the pump. Do this a couple of times then re-test the stove. If it continues to leak back into the pump tube you need to replace the pip in the NRV by taking out the NRV and servicing it. Cheers Tony
@mpr86 Getting the flame burning properly will depend on whether it's leaking air elsewhere in the system; but my test is whether the flame leaves soot on the bottom of a pot. If the stove hasn't been used for a while you might find the flame gets bluer with more use. The lipstick is now not made so look after the one you've got. If it does not burn properly after a while, and you've fixed your NRV, you can gently "peen" the jet smaller with a rounded object placed inside the tube under the jet and a small peening hammer gently tapped on the outside of the jet. Someone here from the USA might volunteer you a pip, but they can be ordered from The Fettle Box (our site owner/sponsor). Cheers Tony
Do you have a tool designed to fit the NRV, so you can access the pip? I can send you a pip, but you'll need to get the NRV out first. Let me know. How did the stove run the last time you ised it? Do you recall if it was ok. Tony explained about the flame, I've peened many lipsticks, but it can be tricky. If the opening is closed too much, unless you have the proper sized micro twist drill bit, you will be screwed. Duane
Sadly I don’t have the tool. I noticed a user on this forum sells one so I messaged him. Do you know of anywhere else where I can acquire the required tool? The stove runs fine but doesn’t get the water to a very powerful rolling boil, instead just a small boil
You can order a parts kit from our sponsor, The Fettlebox. Has all the washers etc. you would need for the stove. Be patient unscrewing the NRV. Be sure the tool is securely engaged and centered, applying downward pressure so the tool does not ride up off the head, then apply counter clockwise pressure until the NRV snaps loose. Hopefully that happens, the Primus stoves are notorious for having stuck NRV's since they did not use a lead washer with them, at least on older models. You want to avoid rounding the NRV head. Duane
I know a gynecologist who got tired of fettling with vaginas and re-educated himself to be a mechanic. He aced the practical excam witch was to replace a gear in an automatic transmission. Also being a gynecologist, he performed the entire operation through the excaust-pipe of the car. The relevance here, is that if you study hard and practice to be a great gynecologist, you may be able to replace the NRV pip through the jet of the stove. Best of luck :-)
