Hello All, I have just got myself a Optimus No8 , ,Green Tin Patent Number stamped on it,a early model I understand. It runs but needs some fettling.I have flushed the tank and fuel pipe out using a hose pipe after removing the jet nipple and gauze. Swilled out with clean petrol a few times,cleaned the jet,and fired it up.........I am getting a weak blue flame with yellow tips. The burner screws on to the tank with no wick just a wire gauze that slips in to the fuel pipe,I gave this a clean out in Paraffin. Any pointers appreciated. I think I will buy a new tank gasket and jet nipple if they are still available? Thanks
Hello, There is no wick? The wire gauze belongs more to the 111's. I have never heard of a 8 or 8r without a wick. So I guess your missing one. Where the gauze came from I don't know. Without a wick some of the fuel at the bottom of the tank would never get used along with other problems. I would love to see some pictures of your stove. Gaskets and jets are still available from basecamp. Cheers, Jeff
Hi Jeff, I will load up some shots tomorrow. I have had a fiddle with the stove a short while ago and now have a very strong blue flame now......a lot more power than my 99 and a lot less control. I have removed a large chunk of debris from the fuel pipe that had got lodged just before the regulating screw tip,this is the reason I had got a low flame before. I looked at base camp for the parts and was unable to see jets for the 8 the thread size on this stove is a lot smaller than the 8R?. Thanks for the reply,I will load up photos of the stove burning and a exploded view of the stove as i received it.
Ah your right Bill! Primus used the older kero jet for the older/early 71's and later changed to the gas jet later on. Here is a picture of the newer jet and older jet for the 8R Jeff
I have just made up a wick refilled with fresh fuel fired it up and this is the flame pattern I have,I,m stuck again!!!!! Cheers
well it looks like your fuel is coming through ok can't tell from the pics but is all the flame coming from the burner? or is some coming from the spindle i had a 123 that burnt like that it was crud in the jet i cleaned it a few times until it ran reasonably well but it never ran properly until i forgot it one day and left it burning for ages this is what happened it cost me a kettle but the stove has been perfect ever since
No it is all coming from the burner,it is very erratic. Last night before i made up the wick the flame was blue running very strong with just a tinge of yellow at the tip of the flame ,seemed to be a bit to powerful. I will go a long with your what you think, crud build up. I will carry on flushing it out if this will not sort it out I may go with a vinegar soak, some thing I did read about on a post here I will let you know how I get on. Cheers
if it was running ok last night and isn't now that you fitted a new wick it sounds like maybe either you dislodged some crud while doing the work or a loose bit of crap from the wick might be causing it if you have a midi/mini pump and cap take out the jet clean it then blow some fuel through the burner with the jet out,if you don't have a mini/midi pump place the stove in hot water and let the pressure build up then open the valve that might wash out any bits lurking inside
I guess the other possibility is that the wick you made contained some man made materials? That mop head needs to be 100% pure cotton only. Cheers, Graham.
Well things are looking better now,still a lot of yellow at the flame tip ends.... any suggestions welcome on this. I would not know if the mop head is 100%, cotton it has been around a while. So the new jet is the same as the Svea 123?..... Thanks for the help.
Hi Tim (assume it's Tim - apologies if not!), My earlier comment about the mop head might have been a bit cryptic on reflection. If it contains man made materials (like being a nylon cotton mix or somesuch) then the melting point of the man made stuff is going to be far lower than the operating temperature of the supply tube when the stove is up and running. Therefore the risk is it'll melt and gunk up the supply tube. Should have explained earlier
Yes it is Tim... and the Tele is short for Telemark,my style of skiing. Any way what I may try is swopping the wick out of my 99,and see what happens. Cheers
you said in your first post you were using clean petrol is that unleaded ? if so you'll be hard pushed to get a pukka blue flame out of it my army No7 (123r burner) go's like the clappers on unleaded but i always get large yellow tipped flames from it panel wipe is much better but thanks to Ian i got to try some Aspen 4t what a difference that makes btw thanks Ian
Yes unleaded petrol....I did read about panel wipe and Aspen on here,I will try it out some time. I am pleased with the results of the fettling I have done with all your help. I only got the stove yesterday,I got it of the French Ebay. Only myself and one other person was bidding on the Stove,I got it for a lot less than I would have paid for a battered up R8 on the UK Ebay. I will order a new jet nipple of Base Camp. Thanks for all your help. Cheers Tim
