37 Comments

  1. Jason has obviously never owned a 2 stroke. He should have seen my melted big end bearing. After running tickover too low.

    I'm sure he doesn't think quite exactly what he says. But he picks videos with attention grabbing titles and this is where there is an issue.

    As you say. What something is designed to run is very very important. Engines need a certain amount of cooling. Too little and they'll seize. I can attests to that from seizing mine….. a couple more times….. than I'd like to admit.

    And this ignores everything else around how well it burns etc.

  2. Your cake analogy is the simplest explanation I have heard yet for why max power takes more fuel than stoichiometric mixture, I'm going to steal/use that next time I have to explain it because it's way quicker and easier to describe 😂

  3. My ex bandit 600 run hot as an oven ,that hot my mates would sit there legs next to the bike as in there on fence at pavement I'm parked on road heat from engine warmed them ,lol I'm serous ,got a kle 500 now ,keeping my fingers crossed ,lol

  4. That’s why ethanol is such a good fuel for performance. Not only does it have a higher octane number so you can run a higher compression ratio, but you need 30% more fuel per charge so you get that much more charge cooling, brilliant if you are running an air cooled engine.

  5. There should be a warning on some of your videos, " WARNING!!, Content may not be suitable for laymen or thick twats ". did you copy half them words from fucking star trek episodes?.great video, i watched it whilst having a shit , it helped

  6. Good vid never understood why you tune richer than 14.7 for best power – if you 'lose' the fuel though, wouldn't it read lean on an o2 sensor so you'd still want 14.7 at the pipe? On the heat thing – won't there be a reduction in flame temperature as you go leaner than stoichiometric though? So if you get lean enough will it counteract the lack of evaporative cooling?

  7. I don't think you are getting your message to us right, and some data and or papers would be good, as you normally provide.

    Look at this image:
    https://www.google.com/search?rlz=1C1CHWL_pt-PTPT817PT817&q=egt+vs+afr+graph&tbm=isch&source=univ&sa=X&ved=2ahUKEwikhNTq94HgAhUbSBUIHXdRBrYQsAR6BAgAEAE&biw=1920&bih=938#imgrc=dRsPDdPk8QVZ9M:
    Just to help out the chart is't in AFR but in FAR so the values in AFR are: (0.05 = 20.0:1) (0.06 = 16.7:1) (0.07 = 14.3:1) (0.08 = 12.5:1) (0.09 = 11.1:1) (0.10 = 10.0:1) (0.11 = 9.1:1)

    It clearly shows that around the 14.8-14.6:1 the cylinder head is hotter and and from there on the lean or rich side the CHTs are cooler and the decrease in temperature is steeper on the lean side.
    As for CHTs, is it meaningful of a hotter or cooler engine system? I'm not an expert and I might be wrong, but I'm led to believe that yes.

    Just to compare running in the best economy zone of 16.7:1 the CHT is as cold as running at 10.5:1 (unless you have a problem your not going to run that rich)

    The EGTs also have a similar trend but at different AFR, we still have rising in EGT on the lean side up to 15.6:1 after that they start to drop off.

    But then again this situation of running lean normally it's only programmed for cruising/low load as it also doesn't need to make much power. Also visible in this chart going rich can net you more power up to 12.8:1 and only loose 5% power going ever richer, and as you go leaner from 12.8:1 (IMPORTANTE NOTE: Not lean) the power drop off is very steep netting you a loss of up to 20% when you go to extreme lean.
    But then there are emissions and… …it's a can of worms!

    One more note, I risk to say that this chart is mostly for port injection as running leaner than 18.5:1 and richer than 9.1:1 with gasoline they tend to misfire and run poorly.

    We want data, we want data… ECHO…echo…co. ho! it's just me! 🙂

  8. On the old Kawasaki H2, 3 cylinder, 2 stroke, air cooled engines, the carburetor on the middle cylinder jetting was intentionally richer than the two outer cylinders. This was to compensate for the lack of cooling fins on that middle cylinder. They were making up for the lack of air fin cooling with extra fuel cooling for the middle cylinder.

  9. im in the karting world.. and recently they released a bigger radiator for iame x30 two stroke and some other bits .. anyways the rad works insane and keep temps really low in there quotes to these updates they said that the engine temp at 45 degrees for less engine wear .. standard stuff alloy piston iron bore.. i would say at 40 to high 50s there should be bare minimum difference in wear infact your probably risking a cold cease with the lower temps meaning its obviously tighter clearances.. and more wear.. i goes big rad has its benefits for summer days.. but i thout it was weird that iame wanted temps down when they weren't high anyways

  10. Fuels with lots of latent heat are awesome!
    Here's the fuel cooling you can get: Units are Joules/(Liter of air fuel mix) @ AFR
    Octane: 24 @15:1 ([email protected] 13:1)
    Ethanol: 116 @ 8.9:1
    DME : 132.8 @ 8.9:1 (Liquid phase DME out-performs petrol on 900PSI direct injection)
    Iso-Propanol : 93 @ 10.2:1
    Methanol : 210 @ 6.4:1
    Methanol : 337 @4:1 ( ! holy shit ! )

  11. So how does the computer change your engine mapping to run leaner or richer? My thinking is using fuel injecting more/less fuel/pressure and spark adjustments more/less spark or advance/retard timing.

  12. Can you explain why backfires happen? Popping out the exhaust? Ive seen and heard people say its cause the engine is lean, but that confuses me because Ive always been under the impresion that a backfire was the consequence of excess fuel dumping into the exhaust, which I would think contradicts the idea of there being too much air relative to fuel? Forgive my ignorance, I just really would love to know!

  13. To repeat what I posted on his video he seems to be conflating exhaust gas temp with the physical engine temp.
    An engine running lean or rich will have a lower exhaust gas temperature, but a lean mixture will cause the physical components of the engine to be hotter.
    Hence the need for an CCT (combustion chamber / head temp) gauge to be used with an EGT (exhaust gas temp) gauge for tuning to know if a low EGT is rich or lean.
    Or at least be aware that mixtures need to be set to be on the rich side of peak EGT and if leaning it off causes EGT to drop, it's too lean.
    Not knowing that can be an expensive lesson or first time EGT gauge tuners.

  14. Moving to 48volt automotive standard we could have smart external heat exchanger variable fans and pumps, pressure temp sensor getting velocity info via can buss. Calculating heat in and removed, given a target range it makes tactical decisions for heat control. Bike Management system makes strategy decisions, and sends velocity to cooling processor.

  15. Can't you go super-lean like 20:1 and get away with it due air and fuel cooling the system on the intake and get great mpg as well as much cleaner emissions? Wouldn't titanium blocks andor pistons be possible with sufficient cooling in such a setup?

  16. All 2-stroke racers always run as lean as possible and then choke the engine under brakes to cool it off. Karting guys squeeze the air-filter. Bikes used to have a spring loaded lever on the bars somewhere.

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