EFI Fuel Injection 420cc Engine ~ North Star E420 Unboxing 

Dude… you could build a go cart with a check engine light! 😂

I've been wanting to see EFI on a small engine like this for a while now. I'm excited to see what you do with this.

Map sensor. Doesnt need a mass air sensor. I think it's refered to as speed density. Usually uses map/tps/O2/IAT/engine temp to control fueling. Dont forget a megasquirt alternate is Speeduino. I use this system. Both use the same Tunerstudio for tuning!

So I’ve had to go to school for these EFI engines they’re trying to make them more like a car engine than anything but each computer whether it be Bosch or Delphi they have a learn process the engine Hass to get up to temperature before the process could really begin the O2 sensor don’t start reading until it gets around 700 720°F and then it regulate the throttle which is what the small rev on startup is once engine gets up to temperature every single smooth out in idle properly. This is especially important for the first time, running it and every time after resetting the computer and easy way to tell if you have a Bosch or Delphi system is to look at the O2 sensor wire if it’s one wire through the O2 sensor it’s a Bosch system. If it’s a four wire, it’s a Delphi and you can contact either company to get parts.

if you look 7:26 you can see where the throttle cable will come into the back of the engine and it has a screw mount to hold the cable and then on the throttle POT there is a place to put that cable end to move the POT with a cable

I've already been hacking on one. The 4 pin connector is a CANBUS cable. Green and Green white are the CAN low and CAN high signal, yellow Green is ground, Blue/red is positive. The other connectors are a remote kill switch (short green and yellow green) and the other is an idle switch that sets the engine to idle {purple and yellow/green) The ECU does not appear easily tunable. Changing the exhaust or the intake will instantly ruin its calibration, as it does NOT have an o2 sensor and cannot detect rich/lean. So changing anything about it renders the ECU, in its current state, incapable of running the engine correctly. Even removing the airfilter or not having it on tight makes it seek and surge. There are PROBABLY commands that can be sent over canbus to edit the injector duty cycle/fuel map tables, etc. I have not split open the ECU. Based on the sensors it has, it is definitely a speed density system, and it might have an alpha-n fallback. You might be able to get more fuel into a higher performance engine by manipulating the fuel pressure, which probably requires an external pressure regulator. No Mass airflow, no o2 sensor. Potentiometer for the throttle is wired to blue white and brown yellow, with brown yellow on the wiper. The starter switch is yellow/green and brown, short them together to start, short them together to stop. blue/red is positive for the lights, blue green is the engine running led, red/white is the engine stop led. IT DOES NOT have a mass airflow sensor. It has a Manifold Air Pressure Sensor, intake air temperature sensor, throttle position sensor, crankshaft position sensor, and an engine oil temperature sensor. Incidentally, i've already made mine start buck and spit on a speeduino.

Stage 2. We’re gonna remove the governor, add a billet flywheel and install a Mikuni carburetor. 😂

If it has a diagnostic connector, you should be able to hook into it and change the computer mapping so it will run with the open-air filter and exhaust. The boys at Grind Hard have done it on 3 of their custom-built rides, I think with the right program you could make that 420 do anything you want.

Confused?? 🙃 So the throttle is the position sensor… just not mounted on the throttle body. So that leaves a servo motor on the throttle body. Waiting for a signal from the ECU. which is waiting for a signal from the position sensor. Hmm 🤔 definitely doesn’t look like that’s the fastest response possible but it does look like the slowest. Still I was wondering when one of these would find its way into your most creative mad scientist hands. lol, Now I can’t wait to see all the really cool and awesome testing you’ve got planned. 👍 This one’s definitely gonna be fun to play with and watch on RU-vid. Ps: Thanks for sharing your mini-bike knowledge.

Ive got to say this would be a sweet upgrade to my Predator 420cc Hemi that is on my Case 222 garden tractor. Especially in the winter it would be sweet to see how EFI would be.

Likely an air density fuel setup, air temp and throttle position determines the amount of fuel. Look forward to seeing the details im still at the unboxing

The tech support person is probably right about the priming. That engine is very likely wired like a motorcycle. They only run the pump when the engine is actually spinning. It is wired in series with the coil so when the coil start firing, then the pumps will engage. The reasoning for it is if you crash. You don't want the fuel pump to be running just because the ignition is on. You should be able to run off the float bowls for a couple of seconds, which is more than enough time for the engine to spin up and then turn on the fuel pump which will then refill the bowls. You could add a push button priming button and figure out an easy way to drain the fuel post-tank. Then you could drain the fuel like you do with a carb bowl, and have a way to make sure it was primed before you even try.

That’s cool! Puts some fueltech to Control it!

Just wait till someone comes out with a tuning software for it or a new tune able ecu. Can't wait to see how far you can go with it being new.

It would be great to see it put on a go-kart, if it's as good as the other 420 etc ,thanks for sharing, all the best to you and your loved ones

i'm stoked for this series and how these things come around with mods. After watching this...there's a long way to go..i've never been a fan of drive by wire.

Patiently waiting for that “Vent tube explanation video that was promised two weeks back. 😂❤

Loved this, I literally saw these last night and have all the same questions, though I’m super glad they give a way to hook cable throttle up out of the box, it does have a delay on the throttle but to be fair so did the first cars with throttle by wire….

As someone that has tuned using MicroSquirt (MS2), I recommend skipping all this nonsense and going straight to learning how to use microsquirt. this system likely uses the head temp sensor to go rich/lean (AKA- dummy switch), and the fuel/spark tables are probably about as dumb as a mule. MS is the way to go. you can like tune it on your dyno. please use a real wideband o2 sensor setup. any old cheap injector will work, but it needs to be small CC's.

Finally, I’ve been waiting for this video

I'd actually be surprised if it had MAF... I figured it would be "speed density", which is based off manifold pressure and RPM to hit the targets in a fuel map. Many OEM engines are spun that way. If it says it has MAF though, I might expect to find the MAF sensor built in as part of the airbox. I'm assuming that the reason it has the fly by wire throttle body is to govern the engine. That pot is likely used by the ECU to set target RPM... probably uses some sort of PID algorithm to adjust the throttle to hit the target RPM. So, the upside is there is no mechanical governor. The downside is the only way to get around it will probably be something like microsquirt (or megasquirt). I doubt fly-by-wire will have have a good response so, I'd personally find a way to hijack the throttle control for direct cable control, or find a throttle body you can adapt to the engine. There is another do-it-all ECU solution called Speeduino, which is built on a generic microcontroller platform... even more geeky than megasquirt, but cheaper. I highly doubt the stock ECU can be tuned. It is cool to see, but the thing is, if you have to swap the ECU, and the throttle body, are we gaining much with this engine? Might be better off just adding these mods to standard 420.

Hey Red Beard, any luck getting this engine running better? Maybe those folks over at Northern Tool would have some pointers? I’m super excited to see what EFI can bring to the mini bike world! It feels like you’re a bearded mini bike riding version of Steve Jobs who has just shown the world the first iPhone! Some people dream of a future of jetpacks and self driving cars, but seriously, I just want an EFI mini bike. A bit weird, maybe, but I can’t be the only one!

Need that second video already. I need to know if this is my next purchase

I made a post about what engine for my garden tractor and someone posted the NT link. Thanks for this video

the plug with bl and y\g and g/w and g is the CAN comm plug, the ecu is going to have to go, it will cap the rpm's and the boost. get someone to attempt comm to the ecu via CAN interface, see if it can be read, and more importantly, written.

Yeah carb flywheel and cam I don't seen getting rid of that slow throttle response

It reminds me of early GM TBI injection where it has just the basics to make it run. I am willing to bet it’s very limited to adapting to mods. Basically a great engine if you are keeping it relatively stock.

I think that's perfect as-is for Grandma's 4-wheel scooter that has trouble on some of the hills in her park on the way to bingo.I think she'd like to drift a couple corners and scare people out of the line to get in her spot quicker. ;)

it does have a crankshaft position sensor which means you can chuck the flywheel for propeller operations, airrboat and ultralight plane, use a belt and pulley on the pull start end to a john deer 2 lb generator for 20 amp charge

Very excited to see the possibilities with this motor. Keep up the good work!

Amen. Lean on him in hard times

I couldn't tell does it have a o2 sensor.

Interesting engine, we should have been adapting small engines back in the 1990s with EFI when they were having success with them on automotive engines. Now we have fallen behind in that regard.

Check out the E300 engines, same EFI and they already sell them on air compressors and generators at norther tool.

Sounded like a governor surge 🤔 hoping you can Gitt'er tuned up ! ☮️

You don't need a mass air flow sensor, that was tech from before speed density became more common place with the use of a MAP sensor to determine air charge pressure, crank angle sensor to determine stroke position and a calculated known displacement as that gives you all you need for EFI, you can up that in accuracy by adding a feedback loop with a wideband O2 sensor. The microsquirt would be what you want for an aftermarket EFI controller for use with boost.

There is a scooter guy on yt. Who was selling efi kits for scooters it had knobs to tune it! It was for 200cc + engines! I'd look into that!!

I was in northerntool this morning and they have a bigger engine then this its a 739 cc and they had it in the big hot water pressure washer skids, that thing looks nice!

Really cool. My son loves the look of those motors

Can't imagine that starting it cold at full throttle is very good for it lmao

Manifold absolute pressure or MAP is what it's using for air fuel measurements. That's a good thing if you can crack the ecu tuning.

Heck yeah that's a good value. I wonder what kind of main chip the ECU uses

Most efi needs tuned...manufacturers will richen heavy and make it sluggish until its broken in. It has tons of potential if it has a good pcm/ecu

Super cool! Can't wait to see more!

Man I want that for my mini bike that is awesome

They literally have a bracket to hook a cable up to the potentiometer to run like an old style set up. You can see it when you take the tank off.

If you could do an instructional on what's needed for a custom EFI exhaust that would be awesome! I want a custom exhaust but not sure about remounting the sensor

Like a few others here, we’re confused why it was surging while running. Was there a mistake made starting? An issue with the machine? Or does it take longer to settle in and self correct?

this would be perfect to put a turbo on, great for the go cart ;)

I bet you hold it full throttle until the Ecu self optimizes/learns. Just like the newer fuel injection swap kits for cars.

So this type of EFI setup is Speed Density rather than MAF. Uses a MAP sensor to read manifold pressure and an Intake Temp sensor then uses those to calculate the density of the air entering the engine. Downside of that is its struggles to compensate when modifications are done that improve air flow unless tuned, which I'm sure at the moment there's no way to tune the little ECUs on these engines lol Most standalone ECUs like MegaSquirt use Speed Density .

theres throttle linkage on the potentiometer and you slide the cable through the case. also most likely you are correct they probably have a tune that they load on that lil ecu. just bc like you mentioned no maf sensor means no air fuel ratio data is being feed to the ecu so no it cannot compensate for the changes made after a owner has added a turbo or small s/c. but you could wire in your own ecu to each component i.e. head temp sensor, fuel pump and so on and yes a mega squirt would work as long as they allow single cylinder motors to be ran of there ecu. wonder if it uses a half effect sensor to crank trigger for timing.

I instantly thought, that an ECU swap using Megasquirt would be perfect.

At the 7:19 mark, looks like there is a lever on the back of the potentiometer that would accept a cable.....nevermind lol

Look at the grom ecu's i think they have the best technology and aftermarket programming

I notice in the specs on Northern Tool, they say the crankshafts on these are forged steel.

Adding an alternator would be easy and solve the issue of the weak factory charging system. I'd remove the factory charging coil and go that route. You might also be able to upgrade the charging coil.

It probably uses a closed loop system. Since no maf or o2 sensor its probably all pre set values.

Probably is an electronic controlled governor. Which explains the surge without a load. Idk though.

The extra intake gasket is a heat shield typically.

Wasn’t even warmed up and making judgements on sluggish ect. Lol

After the 459 predator I'm glad to see your warning people to wait and see on parts availability

I'm sure there is someone out there that will be able to get into the ecu and help you write a good map table for the timing and fuel. It is just going to take some surching. Then when you get really crazy you'll need to find out what kind of injector it has and what the fuel pressure is for that map that's going to have to be worked on.

You would think with EFI it would run smoother than that.

I have always wanted to come up with a simple mechanical injection system but I couldn't find parts or no one would discuss it, I think they thought I was nuts.

I think it has a mass air flow built into that tb plus some of those wires might be to tune the ECU I'd check for sure

Looks a lot better made than the Ryobi 420cc EFI generator engine makes me think maybe the computer needs to auto tune and she will top looping , or maybe when it gets warm... still sucks that it is doing that...

I think the first thing is slap on a forced induction something, turbo or supercharger, and see what happens. Out the box, I doubt you'll break anything. You're not cranking up the power that much. Maybe billet flywheel and some stronger springs, but don't add a cam or anything. Let it do its thing with more air.

The battery is used like a capacitor, know how the light got dim at idle on these engines some times? , well the injector needs a steady voltage because that's how it fires. An diping voltage bouncing around would make it fuel werid an make the ecu not run properly as voltage = speed in working electronics like the injector an the eletric motor contorling the throttle. So it probably has enough to charge while running but at low idle it needs the steady voltage that the battery provides

Yeah I'd like to see you put it through the wringer and see how well it holds up like everything new you're going to have to wait until the parts start coming in for the aftermarket stuff😇✝️🙏❤️🇺🇲💯👍

You need to bypass the governor itself and somehow remap it.. I think it is still to slow based on the sound on how it breathe. Might be nice for constant RPM application like generators. we might need to speeduino or megasquirt it.

get a aracer stand a lone ecu and arf1 wideband 02 it has a auto tune and it can be fully adjusted with your phone via app it has quite a bit of options' i think it would be you're best option .

Extending the fly by wire would likely be troublesome. It's a good thing they set it up for a cable.

Rmember the valve spring hieght tool you were lokking for i found one

I want to see how they do the crank sensor both sides, mechanical and electronic

I may buy two of these and strip the EFI and put one on each cylinder of my VG 23 hp EFI mod lol.

When making changes to intake or exhaust, disconnect the battery and cycle the power switch. That'll clear anything the ECU has learned and then adjust to the changes. Unless it has a fixed running map. Then you'll need a different ECU.

It looks really cool little high tech for me

Love the potential that might be available!

Worse case you could always make a Arduino control if the pedal Potentiometer, and the knob are different Potentiometers are different values

Amazing engine! Thanks for sharing.

What about pressure washers?

Noticing the xmaxx in the background...

You should be able to use a boost refrence fuel pressure regulator to raise the fuel pressure under boost should not need to mess wiiith the electronics

I bet you could probably wire up a Fuel Tech to it. Will be interesting to see where this goes

so if the crank position sensor is bad there is no fault light (probably when it lights up full, thats the CPS is bad.)

In its stock configuration it shouldn’t be much more than a built 224 to torque so it could go on the dyno? Can you get a wide band sensor on an exhaust to check if the ecu is adjusting the fueling.

Biggest upgrade to these types of engines is oil cooler, filter and pump .this will increase engine life when you are tuning for more power ,(come on people it's just obvious to do this )👍

TURBO!

Y’all are thinking wrong it would be a great replacement for my 420cc in my 14’ flat bottom duck boat

The battery for the efi is probably so the generator doesn’t burn up, the battery is there to take the peaks in demand

I would be interested to see if it is more fuel efficient because of the fuel injection, or can you run a turbo on it.

I wonder if that EFI can be retuned for different engines (read sachs rotary)

Look like the vanguard 400 model 25E3

Does it have a MAP sensor? If so Probably just running in speed density mode. Ecu references MAP signal to calibrate fuel. Modify the MAP table in the ecu to account for mods

You start modifying this probably should run a Wideband O2 sensor on it to see what air fuel is!

Is this basically a rebranded engine from the Lifan-powered EFI generators that came out a few years back? I've been wondering what took them so long.

so what i think is going on with the EFI system isn't soo much that it draws enough power to need a battery but more so that it needs a more constant power supply. the charging coils by no means have a lot of power but they should be enough for around 120 watts on dual coils, but the battery probably acts more as a way to absorb the voltage spikes and whatnot due to these charging systems essentially providing pulsed DC. you'll notice this issue with lighting with how the things flicker at lower rpms which is why a fat ass capacitor/battery does wonders for go kart and minibike lights running off the charging system

One of those plugs must be the on/off and's engine start button.

Won't you have to calibrate the EFI so that it knows you want more fuel or does it have some sort of mass air flow meter on it that lets it know that more fuel is needed. Would be interested to see what it can do with E85 and boost.