I couldn't resist buying a renovated Optimus 8R. I just had to have it. I was seduced by the small size and the simplicity of it. I saw a video on Youtube in which the filled the priming cup by warming the tank with their hands. This doesn't seem to work on my stove. It has a cleaning needle. Is this something that can only be done with Optimus 8 or is it maybe the wick that needs replacing or is it something else?
It has to do with pressure in tank before 'warming' the tank. The more difference in temperature you achieve the better it works. Cold tank Released tank pressure Close cap and valve Warm tank Open valve Trickle fuel Close valve Light fuel Preheat Slowly open valve Shut valve if liquid fuel comes out Open later
@kephart - I use an 8m glass fibre wick on my 8R’s for preheating. Works really well. Better preheat using a wick. Pharael.
As you know, all you are doing it with warm hands is building a tiny bit of pressure in tank. But if the fill cap gasket is no good, you won't build pressure. And if you open valve too far, cleaning needle will block jet. First thing I do on these is a dunk test to see what leaks. Open fill cap a bit, put stove in freezer for a bit, remove, close fill cap, dunk in warm water, watch for bubble. I think we all know that lust for a stove...
My response was only focused on the warm hands prime. A viable solution as an alternative. Blowing into tank with valve open until priming dish has fuel is another. There are better options but this one works. I have done it.
Thanks, Are you referring to a wick in the pre-heating cup? That seems to be good for pre-heating. I was however thinking about the wick in the tube from the fuel tank to the burner.
I have done it to see. You need a cold tank and warm hands. It works but an eye dropper bottle of meths is faster and cleaner
Agreed. It would be best to have a torch to preheat. The method is one that works when those other devices are not available AND you need the stove working.
Thanks, I think the tank and my hands were about the same temperature. The stove works fine otherwise both with meths and petrol-fuel priming. I'm not to too impressed by the boil times though. It seems the burner is very sensitive to wind. I should have used a windscreen. With just a little bit of wind it took about 11 minutes to boil half a liter of water.
I use folding aluminium plate windscreens for almost all of my outside use of camp stoves. Inexpensive on the Bay of Evil, and versatile for different stoves. Cheers Tony
Since these thing build their own pressure, if there is even a tiny loss of pressure they get really anemic. Dunk test! Or just change fill cap gasket. Can make a big difference. And yes, windscreen
Thanks everybody! I can report success on all fronts. A simple windscreen made out of aluminium from a pie bought in the supermarket made wonders and the boil time for 5dl of water was now about 6-7 minutes. I also primed the stove using hand-warming of the tank. I think what I did wrong last time was the setting of the valve. I did not correctly place the pricker needle. I now started with it all shut (all the clockwise) and then heated the tank and tested a bit back and forth. I do see however why meths could be preferred since the priming fuel produces a bit of soot and the flame is not as controlled.
@kephart - I use denatured alcohol rather than meths for preheating. Cleaner burn producing less soot. Personal choice though of course. Pharael.
