Friday, March 24, 2023

Our 10k RPM Stage 4+ 212cc gets E85!

Main Our 10k RPM Stage 4+ 212cc gets E85!

Viewing 34 posts - 1 through 34 (of 34 total)
  • Author
  • #81191

    Our 20+ horsepower 10000 RPM Tillotson 212cc engine gets an upgraded carburetor and E85 fueling! We order a wideband O2 sensor and air to fuel ratio …

    tyler larson

    That innovate wideband is setup for gasoline so your afr's should be around 12.4-13.0 at wide open throttle on e85 depending on where the motor likes it


    The only family fun center type go karts that aren’t slow, stall a little or backfire. I wish those type of gokarts at tracks were like that! Great video guys and hope to see more!

    andrew w



    The A/F Ratio wideband sensor doesn't care if you are running Gasoline of E85, it is looking for a level of oxygen in the exhaust. if you are running 14.7:1 (stoichiometric) with gas, then switch to E85, when you get the A/F Ratio correct with the proper Jetting, the gauge will still read 14.7

    Jon Lasaga

    You would probably get much more power out of e85 in a fuel injected setup than you will with carbs there's not nearly as much room for adjustment with carbs

    Orion Crane

    Your target on e85 will be exactly the same as on gas. Since the sensor is calibrated for gas. 12.5 actually sounds a little too rich to me. I’d shoot for like 13-13.5 for an n/a engine on e85 read by your o2. Your actual afr will in fact be around 8.8-9 but it will not read that way on the gauge


    Can't you build something with a 2 stroke engine instead of a 4 stroke engine

    Rich B.

    I think E85 in a small engine with no boost or ability to advance the timing is a waste of time. Keep in mind that the hot rod guys using this stuff run them super rich and they also run a ton of timing advance to take full advantage of the higher octane of E85. Most of these applications are boosted as well so they need all the octane they can get to keep detonation or spark knock in check. Straight gasoline gives more BTU's per combustion cycle and therefore more power…if you can keep the engine from having detonation problems or leaning out. Unless you can advance the timing on this engine you are actually making less horsepower on E85 than straight gas. If you were to dyno an engine tuned for gas and simply switch to E85 without retuning, the numbers would drop. E85 loves timing…..lots of it, and a real fat mixture. I think your high speed gains were more the work of the bigger carb venturi than the fuel itself. And as with any size engine..the bigger the carb venturi, the more low end torque you give up. Try some non-ethanol gas in that engine and you might be surprised once you get it dialed in.

    Ivan kacarov

    dude have you thought about making go kart from old diesel generator the size is almost the same like 250cc petrol engines 🙂

    That93white del

    Link to wideband and gauge used?

    John Rimmer

    Put a hotter plug in and change your gap see what that does

    Bike Life_93

    I think it’s time for some 2 stroke builds. There are lots of old Skidoo engines out there.


    lets go to the board so i can give you all a lesson because i'm mr. know-it-all LMFAOOOOOOOO you stupid little boy you dont know crap!!!!! an you even said later that you screwed up but you want to teach everyone how to do it the right way?????? HA HA HA HA HA HA HA shut up little johnny boy an keep sucklin mommy an daddy's tit.. WHAT A JOKE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!


    If you are using the wideband stationary add some continuous load with the brake or actually drive and check the mixture. 12.2 under full load is what I aim for on my Sun Rolling road Dynometer. Also check full load first and change main jet to suit , then work on needle profile for the mixture ramp to full throttle. Great video as always.

    john beach


    brian ramsey

    Love the videos you guys do


    you got to add timing with e85


    Please no more beauty shots of an electrical arc. Really. That's like tide pods for the eyes and only appeals to 15 year olds.

    Jesse Haskins

    I see the problem with your situation. The AFR gauge is more than likely calibrated for gasoline. However the O2 sensor simply reads lambda. Lambda could care less about AFR. Lambda simply determines if there is any left over oxygen. The gauge is converting a lambda to AFR. At idle you want a lambda reading of 1 on E85 or gasoline. A lambda reading of 1 is essentially saying that there is no left over oxygen and that the burn mixture is perfect. However, the problem you guys are running into is that the gauge is converting lambda to a gasoline mixture ratio (AFR) even with E85. So the gauge is going to say that you guys are running a 14.7 AFR when in reality it's running a 9.8 AFR because of the different fuel and lambda correlation. What I would do if I were you guys is take your target AFR on E85, convert that to lambda, then look up that lambda in gasoline AFR. This will be the AFR you should be targeting on the gauge. For example, if you are targeting a 8.8 AFR on E85 the gauge is going to read 13.2 AFR. Hope this helps.

    andres hernandez

    Love the shoe guys I used to watch y'all guys a couple of years ago but now I remembered your channel I got inspired to watch you videos again 😎

    Exotic Creature

    E85 combustion leaves behind muss more free oxygen content in the exhaust gasses. On a car that isn't flex fuel this extra oxygen will cause low voltage readings from the O2 sensor which the ECM interprets as lean. Because it isn't calibrated to increase fuel by the necessary amount the low voltage readings continue and the check engine light will turn on. I do believe Tillotson also offers mechanical injector units for small engines. It may just be worth it to use that instead of the carburetor


    Contact Mighty Car Mods. They love E85

    mike bogardus

    Add timing!!!!

    Kevin Sharma



    @CarsandCameras When are you guys going to zip tie or clap your oil tubes? I remember you guys had problems with them coming off id figured you'd want to at least zip tie em down so they wont blow off again due to pressure.


    The guage doesnt give a fuck if its e85 or gasoline u still target the same afrs. it just takes more ethanol to get the mixture u want. thats it! make sure your wideband has been calibrated in free air first and make sure the bowl isnt drying up at wot. You may need a low pressure pump. You could always use a clear bowl and strap a gopro next to it to see if the bowl is staying filled at wot


    i guess the carsandcameras grand prix is gone now

    andrew fehlen

    I have a polaris efi 500 snowmobile engine……


    E85 that's lame we have 98 or 100

    Austin Is a Person

    My uncle is willing to sell a snowmobile without a track for $100. All the parts are there except the track. It’s an ‘85 ski doo formula ss. Text me at (419) 777-6975 for more information. Please thumbs up this comment if you want to see them smack a snowmobile engine on that sucker.

    Nathan Hensley

    What cam y’all running


    Food for thought, the hole sizes in mikuni carb mains is directly related to the number written on them. #100 is 1.00mm
    #85 is .85mm

    So you guys drilled to .055" which is equal to a #140 mj.

    Thats not unheard of. My old 1100cc bije had #125 mains on the 24mm carbs so i doubt you need a fuel pump or larger needle and seat on the float.


    switch to a lambda gauge and you will be much better off.

Viewing 34 posts - 1 through 34 (of 34 total)
  • You must be logged in to reply to this topic.