In the past two days there were a lot of discussions on the Optimus Nova addressing concerns regarding the filter, mouse tampon (filter on the plastic pick-up hose) and the like. Having a new Nova, I thought it must have been just a remote incident on some stoves. I decided that since I was not sleepy yet (midnight) I decided to try to fire up the new stove. Followed all directions in the manual, primed it with meths and opened the spindle No flame . Perhaps it needed a 2nd prime still no flame when the spindle was opened And so the stove tools had to be prepared like preparing for a surgery. First suspect was the filter as with previous topics. I removed the spindle/nut and tried to blow through the hose where it connects to the pump jeeeeez it was totally blocked. So I took out the other end of the hose to look at the filter Not good at all I wondered how the darn stove passed the test as there was a red tape at the bottom of the stove that said "PASSED" was it passed the test or just passed through someones visual inspection Alright so what could I replace in leiu of the OEM filter. Aha! Lance's brass mesh to the rescue. After looking for a suitable form in which to make the filter, I settled with one of the pot support of the SVEA 123 which was a loose fit where the filter sits. I placed it on a mini vise, and cut a swatch of brass filter With my fingers and a hard plastic, I pressed down on the mesh until it conformed to a cylindrical shape and using a sharp cutter, I cut away the excess brass. I carefully inserted the brass into the hole with the help of the blunt end of a smaller diameter drill bit The rough edges were coaxed to bend inward using a hard plastic before connecting the hose back. Alright, I said to myself it should fire up. Having gone through the checklist, I primed her up once again, opened the spindle and "NASA WE HAVE A PROBLEM" it still would not fire So I suspected it was at the pump end that was giving a problem. I remove it from the fuel bottle and dried it up removing the screwed on quick connect coupling. I could see the hole but when I blew air from the pick up tube, no air would come out the other end. So I decided to remove the plastic hose from the pump housing only to find that it was blocked by plastic. The same plastic material as the pick up tube. It was hard....felt like it had melted and solidified and completely blocked the hole. With a small drill bit, I unblocked it and remove the blockage and when I was satisfied that I have removed 90% of the plasticky matter, I screwed on the pick up tube and reconnected the quick connect coupling on the pump housing. Feeling confident that all passages were clear of any obstruction I prepared to fire her up (oh by the way I was using kerosene fuel) and the third try was indeed a charm I had to let it run for about 20 minutes throttling between full and simmer before getting a real good flame. Ah yes, its always best to test a stove making sure it is in working order before taking it out in the field That way it will not let you down Ron
quite astounding, isn't it? it's almost as if the company wants to self-destruct... i ran into many problems with my Hiker Plus out-of-the-box as well... glad you fixed the stove!
Ron, "Passed" has nothing to do with the quality of the stove. "Passed" means that Optimus has passed the problem on to you. HJ
Hey Ron, Sorry you had an issue with it right out of the box. was it plastic from the tube threads, when I took mine apart yesterday, I found what looked like a small piece of thread cutting in that same location but it wasn't blocking the fuel. Using only the tool that came with it, I took it down as far as I could in about a minute and a half. The o-rings on the spindle looked new. Lubed them with some silicone grease. The one under the disconnect coupling has a nick in it. It doesn't move and still sealed, but I replaced it with new viton one just the same. Re-assembly went about the same. I tweaked the flame spreader to fit a bit more snugly and fired it up and checked for leaks. AOK. Picked these up a couple years ago at Harbor Fright. They've really come in handy. The viton ones on the upper left cost almost as much as all the rest combined. Viton's been around since the mid 1950s. Don't know why it's so expensive. Hopefully with Kalrez, Chemraz, and Simris, the price of Viton will go down. Haven't tried any of those yet. Mike
Forgot to give you the big thumbs up for stating the importance of pre combat checks and inspections. Many family outings have been ruined and many lives lost by failing to inspect and test gear prior to the big event. Like your screen filter mod. I'm adding that one to mine. Mike
HJ, oh that what it meant - passed on the problem to the user toonsgt - well I have learned from the pro's. My former boss was an ex USMC Captain and he'd yell at me hard if I did not check my dive gear 3x before going on a 100feet deep dive or not checking the chase car before actually using it on a security detail (burned a lot of rubber there and some axles in the process). Lovely viton/nitrile o-ring set you have there. Now I know who to ask if ever those o-rings get busted Yes, it pays to check all your gear before going into battle. Ron
I was just thinking about some of the mesh I have seen in a few of the stoves I accumulated this year, may or may not need to be replaced. I mostly need to see how many and of what size pump cups I need and order some, then I won't have an excuse to not work on my recent collection of paraffin stoves. Slow progress, at least I got a few stoves running last weekend in-between working with firewood and yard work.
I've been trying to find some brass mesh/screens, but all I find (on-line) are the little circles for pipes. Seems that pot-head suppliers have cornered the market.
I got the brass 100 x 100. Cuts easily with scissors or a knife. Rolls very easily too. Stainless can be had at much smaller mesh size, but is not as good at conducting heat, which is the whole idea for vaporizers. I know that some of the original ones had stainless mesh, so I don't know if the difference in conductance between the two is even measurable in this application. Mike
Henrik, you are of course right again. I got off on the vaporizer tangent because that's what I bought it for. I didn't do a very good job of getting that point across. Definitely a finer mesh is preferable for filter applications. Thanks for keeping me on my toes. Mike
Does the mesh filter material have anything to do with the vaporization process?If you were to only use clean fuel could you get by without the filter in a pinch?Thanks, Phil
Phil, On the Nova, it has absolutely nothing to do with the vaporization process. I bought the screen for my US military stoves that use the small bullet shaped generators with rolled mesh inside. This would simply be a retrofit to replace the little ceramic disc that clogs if you look at it while holding a can of diesel. I've run mine sans filter for a few years now with no issues. But I am more careful about making sure the fuel is CLEAN. Do I recommend no filter? I would have yesterday, but not since Ron showed us his idea. I didn't like the idea of putting a fiber filter in there and have loose filaments creeping into the guts of my stove. But the wire mesh seems to be a GREAT idea. That's why I'm cutting a piece of mesh for mine now. Mike
