An old thread on here made me think about this five year old Polaris. It's my only non-vintage Optimus, so I can't gauge if this is simply the sound/behaviour of a healthy copy of modern Optimuses. I went from shrugging my shoulders to just wanting to know. That's what happens when I put a pot on it. It pulses like a helicopter. Initially I figured "this is how the stove sounds" but then read people solving this with valve adjustments, spreader plate height changes, varying the number of pumps, fresh fuel, and even using a Primus pump (and ran a Whisperlite Uni off the Optimus pump perfectly BTW), etc. None of these tweaks altered the pulsing. I've disassembled it and cleaned thoroughly and checked orings, replacing one that really didn't need replacing but was closest to it. So is this normal? Did everyone who has this just buy a Polardog and call it a day, because it simply sounds like a stove that can't burn fully, but I can't even approach the experience level with Optimus burners that some of you have.
And without the pot on top? What fuel are you using? "Did everyone who has this just buy a Polardog and call it a day," Can't talk for "everyone" but many sure did...
@Odd So I've added this example of full blast with and without a pot. I'd say "oh my kitchen doesn't have enough cross-wind", but all other stoves work when tested here. Fuel: freshly purchased Coleman Fuel/white gas
Obviously it is related to having a pot on it - so don't. Just kidding, I'll dig my unaltered Polaris out and do some experimenting. I just hope I can find the flame plate. All my Polarises have BD hats... How's it doing on part throttle? I trust you're aware full throttle just wastes large volumes of fuel without the energy / heat being absorbed by the pot... /Odd
I tested my unaltered Polaris ( I found the flame plate! ) using alkylate 4-stroke petrol* and it sounds very similar to yours when I put a 1.4 litre Trangia kettle on it. Roughly the same frequency on full blast but maybe slightly less sound volume (but that's hard to judge, could be a factor your camera interferes in). And less pulsating sound without the kettle, just as yours... Btw. Pre-heated with alcohol just as I'm used to... So I'd say your Polaris is within specifications. Nothing problematic at all... This was the second time ever this Polaris was fired with petrol - I always use kerosene or Jet-A1 in all my Polaris's. Don't like the volatility and extra risk involved with petrol as main fuel. The slight advantage of pre-heating on the main fuel don't outweigh the extra risks imho. Ymmv - of course. And: with the BD PolarDawg2 fitted - everything gets so much better; quieter, better simmer ability, less violent flame etc etc - at a weight increase of a mere 36 grammes (1.27 ounces) for the entire stove. You'll never look back... *which is the closest to Coleman Fuel I have, and it's close enough for this type of testing. A one quart bottle of genuine Coleman Fuel can be bought in Germany for something like EUR 8.90 - which is roughly USD 9.80 - but it's forbidden to send it in the mail so I haven't bothered to get it just for experiments like this... Cheers, /Odd
@Odd I'm grateful for you going and taking it out for a test, and now I can stop wondering. I always pre-heat with alcohol--it just makes sense, and I'm excited to see what the stove gets transformed into when the PolarDawg 2 arrives. Thank you for doing that!
My Nova used to sound exactly like your Polaris. After raising the flame plate for kerosene and using a lower plate for gas, it no longer helicopters. @Odd , didn’t you share this trick with us?
Sadly for me no extreme or middle spreader adjustment worked, though I’ll be giving it a higher position just to run some kerosene to see how it does with that fuel. We have a good supply of affordable white gas in Canada so Kero doesn’t get much use, but curiosity and any excuse to run it win!
I got my Primus Omnilite Ti and also MSR Dragonfly throttling like that. Maybe it's has something to do with the fuel debit. So, I turn the knob on the stove to maximum, and reduce a little by little the knob on the pump, now it's not pulsating anymore. The flame is still fully roaring but more stable. I think it has something to do with the stove capability of burning every cc of fuel per second, even in full roar.
I thought I’d come back around for an update on the pulsing. For context, I own a couple of Novas and a Nova+ that don’t do this (I swapped Polaris and Nova hoses to isolate issues), so it’s not some massive user-error issue, but it just so happens my Polaris is VERY picky about jets. Swapping through the various stoves’ jets gave me consistently good results on the Novas but the Polaris was only happy pulse-free on a brand new jet I bought as part of the repair kit. Here’s the frustrating part: that jet had a manufacturing defect that sent the fuel slightly off centre on the flame plate. Worked great, just ugly to look at and it made one support light up red hot. That jet also messed with the polar dawg cap making a lopsided flame pattern. Finally got another kit yesterday from my local supplier, and the stove now has a centred flame that doesn’t make that helicopter sound and works best with the aftermarket cap. The old flapping Polaris jet works well in the Novas oddly enough, so it lives on a spare. So that’s the end of that journey. Thanks again for the helpful suggestions. Learning the quirks of this one have been fun (minus the time and cost of tracking down those replacement kits—they’re like hens teeth in Canada!).
