Dont worry mate ... just think ahead when all us old farts are dead and gone and cant taunt u anymore , and you are the shop floor manager and u ride to work and back on your brand new BMW1000 and are built like Arnie ...... you can have the last laugh
Jets are stock, clean and in the proper holes. Icing?! Shoooooot. There's a thought. If it ever stops raining/snowing today I'm gonna try blocking off half the radiator with cardboard to hold the heat in the motor and go for a ride. These bikes don't have a cold limiter built into the ignition box if the coolant temp sensor isn't past a certain range, do they?
Icing should be a slow developing problem, more common on aircraft, but the cooling of evaporation might make it difficult to draw enough fuel. So stock jets mightn't be enough. Also, if the air filter or exhaust system is changed than it'll need rejetting. Does it rev past 12k when stationary or is it only under load or full throttle?
Rode it today, it's hits 14ish now intermittently. Air filter is brand new and stock. Exhaust is stock too. It revs higher unloaded than loaded. I'm thinking on calling in the professionals before I blow it up. Get it on the dyno and a wideband before I break it.
Cold weather, particularly as cold as you are talking about, means that the air is a lot denser, so needs to be richer for that extreme. Even though I am always telling people to stop fitting bigger jets in this case I will make an exception, well worth trying some larger main jets. I think most humans don't like riding around in the snow
The logical answer is don't ride until it's warmer, but where's the fun in that? I don't like riding in the cold/snow/rain, but I'd rather ride in that than not at all! It definitely feels like it's going dead lean though. Either that or the clutch is slipping in 2nd, which would be ass-backwards.
Well the good thing about the cold is you get quite a bit more power. Lots of suppliers in the States have main jets at good prices so should be an easy task. Try going up by 10 and see how it performs.
Another point to ponder is... are you running Winter grade fuel?? The RVP (Reid Vapour Pressure) will be substantially lower in Summer grade fuel which will affect combustion...
we need to work this out, you are so close. Can you PM me your engine number, I want to confirm its a C model engine ( have we done this already ? ? I cant recall)
My vin has an O instead of a C- we never sorted why when I asked a few months back. https://2fiftycc.com/index.php?threads/should-my-engine-and-chassis-vin-match.9015/#post-93134
That is going to make the problem worse. http://www.tomorrowstechnician.com/performance-primer-tuner-and-hooch/ http://www.hotrod.com/articles/wideband-oxygen-sensor/ Maybe get some 10, 15, & 20 larger jets
Wouldnt worry it if it was EFI as the Computer compensates with fuel and spark.. Carbies... they prefer minimal temp change... minimal altitude change.. and really prefer WOT....
Too bad I can only wot to 12 or so . Can't argue the temp component tho! Or the differing fuel needs.
Ethanol contains oxygen in the compound, so it is lean already, might have to lift the needle, too. A small washer or o-ring would do.
So alas, today it started snowing again. There was no dyno time for me. So I ripped the engine in the Ducati apart to get to the clutch. Why yes, I AM a glutton for punishment, why do you ask?