Hi. My newly arrived 8R does not build up pressure the way I expect i to. After 5 min calm burntime it still did not, even if the tank gets hot. Installed the pumpvalve-cap from my 123R and gave it 10 pumps. All good and keeps roaring. Had another 8R some years back and can not remember it having this problem. Will have a closer look at the original capvalve but it seemed to be ok. Anyone who have exp the same issue and found the problem?
Hiya, most likely the cap seal is leaking. Try placing the brass tank and burner in very hot water and look for bubbles of fuel vapor. You can get replacement SRV pips and cap seals from the Fettlebox. Cheers Simon Foxxx
I agree. A very small leak will allow a flame to keep burning but it won't build enough pressure to roar like it should. What happens with the good 123R cap if you do not pump it?
One of my favorite things is my little spray bottle of soapy water. Spray around fill cap and watch for bubbles. Ten pumps is a lot IMHO, should only need a couple.
The pump and associate cap for it, will only show if there are leaks elsewhere and that cap may leak also. The standard cap may still leak or the SRV, as I had a couple stoves leak out the SRV in the cap. To check the regular cap and SRV, I loosen the cap up and place the empty tank in the freezer for a bit, remove, tighten the cap, dunk in warm or hot water. Be sure the valve is closed on the burner. Duane
Thanks y'all ! The problem was the filler cap gasket. I will replace that and the valve-seal. Fettlebox next.
That's good news. The valve seal? You may just need to tighten the nut a little more. Just enough to allow the spindle to turn, but not so loose that it leaks. If the filler cap gasket was hard, there is a chance the SRV pip is also. Keep an eye for a flame on the cap's SRV hole. There are a lot of posts here on how to check and replace the pip in the SRV. Yours looks like a square SRV fitting. Ken in NC
A temporary fix is a O-ring in the fuel cap, but don't over tighten, it can distort and loose pressure. Duane
I adopted the oring (viton) solution as "temporary" many year ago, and it is still there, in the 8R that I use quite regularly. It did not deformed, even when occasionally over tightened. Maybe I have just been lucky, or perhaps is the right size (at the time i got what was at hand) Maybe the viton is the trick.
Wow. Come to think of it I did use an o ring I had laying around several years ago on one of my Enders 9061 fuel caps. I forgot to replace it with a viton washer I was going to make for it. Took the stove out and checked it for leaks. None
The new seals did make a diffrence, but it will not roar. Does so only if I use a pump. Would you like to comment on the videoclip?
Nope. The stove was sold as "unused", but I think it had been testfired. It has probably been left to dry for decades. Could be the wick needs to be replaced but Im not the one to tell. The end in the tank looks clean
I have few coil burners that have a wick: https://classiccampstoves.com/threads/no-problems-with-pre-heating.30371/ They have been unused for decades... It takes some time for a wick to absorb the fuel. Have you removed the jet from the burner and put some pressure to the tank when tank is full of fuel? That would fill fully fuel line with fuel. Then let wick to absorb the fuel for day or two.
I know this thread now should be moved into the fettling Department, so maybe the moderator could assist. This spare-kit holds parts for both the 8R and 123R? Another question, why the wick? Why was these stoves not designed like other stoves and the pressurelamps with the puelpipe reaching the bottom of the tank?
Am I totally wrong suggesting that the wick is a feature on self pressurising stoves, so that there always is fuel in the raiser tube, even when it is cold? When lit, the fuel that already is there is vaporized. Regards, Vidar
Hi, your Op. 8r is designed to be self pressuring so a wick is used to ensure that fuel is available at the jet even when the tank has just been sealed and there is no pressure to deliver fuel for priming or running to the jet. Once the stove is running, thermal feed-back heats the air above the fuel and pressurises the tank and ensures fuel delivery to the jet. You must ensure that you always leave a gas space above the fuel when re- filling the tank. A maximum of Three-quarters full is a good rule. Similarly after using the stove, and allowing the burner to cool, release the gas pressure, then re-tighten the filler cap, so you are ready for the next start-up. If you don't do this the tank will be at negative pressure when next you try to start. Best Regards, Kerophile.
