Hello my name is Fred and I am new on this forum. I am 30 years old and live in Surrey (UK). In inherited two old primus kerosene burners from my grandfather. These are in tip top condition and come with a whole bunch of original accessories. When I tried to fire them up they started to leak fuel through the hole in the cap where the pump rod enters the pump cylinder. The more I pump the more fuel it leaks. I think that there is a problem with the valve that is supposed to let the air in but not to let the pressurised fuel out. Is anyone familiar with his problem? Is it worth fixing?
Hi black thunder welcome to CCS it it is the non return valve it is a common problem and is well worth fixing, it could be a bit of grit but normally the rubber pip in the non return valve has become hard and wont seal or the washer that goes around the nrv that forms a seal in the pump tube, you will ned a non return valve wrench you can buy these parts from base camp the sites sponsor or on here if you go too the clubhouse and then trading post you can buy the wrench for the nrv from Stu who makes them himself and are far better than the ones supplied in the service kits, the NRV pips and washers you can get from Ross the site founder who makes them from viton rubber send them a personal message for details. If you look in the fettleing forum i have just done a restoration on a veritas 1 pint picnic stove there is a pic of the NRV taken apart in order you can see how it works
Hey there welcome to the site! I was a newbie not long ago myself. Trust these guys and what they say, they won't steer you wrong. Though some of them do use terms that aren't familiar like 'NRV' it stands for Non Return Valve. It's a one way valve in the bottom of your pump that doesn't allow pressure or fuel to come back into the pump for obvious safety reasons. And yes, as Brian said, the rubber is probably hard from age. No big deal, contact the guys here and they'll get you sorted out. Again, welcome to the site and to the friendliest community of stove-nuts you'll ever find!
Welcome aboard the Ship of Pyros(Tm), Fred. Duff NRV's are easily fixed, just take out the pump rod and find yourself a steel rod/bolt as near as you can manage to being a neat slip fit into the pump tube. If it's a bit small, you can pack up with gaffa or electrical tape. Cross cut the end of the bolt/rod with a hacksaw until it's a neat fit, neat being the working word here, the NRV is only brass and could well be tight if not actually stuck from age. Don't worry about this just yet, build your tool if you can't/won't buy one and just proceed with caution. It's not a hard operation. There is a fearsome amount of know how here abouts, it's unlikely you'll find yourself in a situation that doesn't already have a post to cover it. Pictures, man, pictures!
Base Camp sells everything you will need to get these old stoves going again. You can make an NRV tool if you want to, mine is just a slot cut into 10mm steel rod, sized to fit the end of the valve. There are flats filed onto the other end for an adjustble spanner to grip it. Its shaft is wrapped in gaffer tape to the diameter of the pump tube to keep it centered in the tube. You should also replace the washers under the fuel caps, these will be hard and not sealing well. They may work a bit now but they will fail eventually. Viton or nitrile rubber washers can be had from Base Camp or 'spiritburner' on eBay. New pips for the NRVs can be had the same way. Ordinary rubber will perish within weeks of touching fuel. Let us know how you get on
