EFI for 50cc-250cc Scooter! (UPDATES!!)

[acdnate]

Thanks for the thread and the detail provided. I found out about the EFI systems on another forum and was directed to this thread. Lots to think about and draw from your experiences.

I race in a mini roadracing series. The bike I'm contemplating going EFI on started as a Honda CRF100F. The motor is not stock anymore, but is still a pita to get tuned correctly when changing elevations and/or weather conditions. This could make life much much easier trackside.

[mainepeace]

Latest info here!

My tires were a bit low. So low in fact that the rear tire popped the bead when I was pulling out into traffic from my shop. Thankfully, nobody was coming and it happened right in front of my shop, so I wheeled it down and filled the tire. Wouldn't you know it happened when I will get my new all-weather tires on Tuesday.

Anyway, after filling the tires to 35 PSI front and back it made a huge difference from the 15 PSI or so it was at (front was at 15 when I filled it).

CHECK THE PRESSURE IN YOUR TIRES! My tires actually "felt" ok to the touch and they looked fine, just the rear tread a bit low and worn on the left side (what's up with that?). I can only think that it wears a bit more on the left side because of the weight of the engine which torques the wheel a bit. Anyway, I didn't think the tires were too low (never pressure tested) and it cost me. At least I didn't dump the scooter in traffic with people behind me while going 50 mph on a curve!

I have been having a bit of a problem with the oxygen sensor. The original one kept giving me error codes and the replacement one came apart due to a manufacturing error. I have the ECU pretty well tuned in open loop now so it's not a big deal, but it will give a bit more power when everything is running perfectly. However, the ECU DOES auto-adjust, so after a while it will optimize itself. Not as good as with an O2 reading, but I've noticed that within a week of the last calibration file I got from Matt it has gotten significantly more powerful and the engine "sounds" better. Starts right up each time and the idle sounds strong. Anyway, I pushed the sheathing back together for the oxygen sensor while waiting for the replacement and it's not kicking a code, though it's still running in open loop.

Anyway, with the EFI system finally tuned, the system running properly, a 55 degree ambient temperature and properly inflated tires, I was getting over a 4mph boost from just yesterday in the same locations.

I have attached a screen grab of the data recorded from the ride home today. This data is about 1/2 hour old. If you look at it, the scale is for RPM's with the RPM curve highlighted. Each of the dozens of datasets can be selected and individually measured this way. You can even compare the data from two different runs if you want.

This graph shows:

RPM
TPS (throttle position sensor)
ECT (engine coolant temperature read from the valve cover)
IAT (intake air temperature read from the air filter)
SPARK (spark advance from TDC)

It's difficult to read without the different scales, but the TPS goes from 0 to 100, and the spark advance is basically at 0, 9.5 or 35 degrees. I can tune the spark advance more if I feel like it, but the stock settings seem to do well.

(more)

Greg

Attachments:

[mainepeace]

Here is a zoom into the run down Main Street (which is a 35 mph zone). I hit over 50 on the speedometer. At the flat spot on the RPM curve it was showing 53.

At the start, when I went to WOT (wide open throttle) you can see the RPM's jump up to 7765 then dip down 6259. This is when the sliders engage. I need a performance variator to remove that dip as the sliders (Scrappy 5.0g) are slinging out at the improper time. Ideally, they would go out a bit faster at the beginning, so the engine doesn't rev up so high, then stay there a bit longer as the engine accelerates, so the RPM curve is actually pretty flat until the sliders hit the edge of the ramp.

The RPM curve then goes up to 8200 then dips back down again as there is a small hill. It goes back up to 8500 where it flattens out. That's the back side of the small hill. It's plateauing because I have a 9000 RPM limiter set up in the ECU. (Hmm, maybe it's actually 8500, I'll have to check that). Anyway, it's easy to set a limit so you don't grenade your engine!

This system, when properly tuned, is DEFINITELY worth the $300 (plus welding costs) price tag. With the system, plus $20 sliders from Scrappy, I have gotten a RELIABLE scooter that gets over 100 mpg and has increased the top speed from 45 to 58 at the same locations with the same speedo gauge. The hill climbing power is MUCH improved, without resorting to a stronger torque sheave spring or other clutch improvements. Everything else on the scooter is stock (EFI kit comes with a sock air filter and a 24mm TB). The 24mm throttle body does not have a big negative effect on power as a 24mm carb would since the fuel is metered. Sure, there is a reduction in air speed at low RPM's, but it's not a big deal. Ideally, a long intake runner (like this intake www.scooterpartsmania.com/scooter-high-perfomance-air-filter-and-pipe-87704-p-2777.html) would give a boost at low RPM's.

I can keep up with traffic, and can even SPEED in the 45 mph zones, as long as it's not uphill. I can go up hills at 35 that only last month I could only do 25->20 up.

Any airflow modifications, like changing the airbox or changing the exhaust is automatically adjusted for. I can't wait until I do some porting on the head, which will really open her up. With the difference in power from just a 20 degree temperature change being huge, a change in the intake and exhaust flow will have a tremendous impact. Think about it, you're getting a 24mm TB (permanently replacing the carb) and a customizable and tunable system that will give a 20-25% increase on a stock engine. It's reliable and won't overstress the components as much as a 72cc upgrade yet will give you comparable power. I have yet to go head to head with a 72cc scooter. It will be interesting to see the results.

Greg

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[imnts2]

This is a very interesting and good thread that I think deserves being brought back to life. Do any of us know anything new about the subject? Have any of the problems been solved? Etc etc. There is now several factory scoots in the smaller sizes that are EFI so perhaps the aftermarket guys have some solutions now they did not have before.
Cheers
lefty2

[mainepeace]

Pretty much the only issues I had were calibrations (which are now solved) and the power draw, which was solved with the LED brake light and a larger battery. I do have to occasionally charge the battery, but it's something that you should do anyway with a Battery Tender, Jr. or equivalent.

The temperature now is in the 40's at times. The power is tremendous and I love that it keeps coming the colder it gets.

I'm consistently getting 50 (gps) at spots where before I'd only hit 35. Partly because of the greater acceleration, partly because of the greater torque so I can climb short hills faster and exit a corner at a higher speed. Oh, and the Boric Acid treatment has helped tremendously.

I do have some cold start issues. It takes two tries to start, but mainly that's because I don't pump the starter. I just hit it for 2-3 seconds then start. I think I just need to tweak the cold fuel tables a bit more, giving some more gas. However, last year with just the carb it would take 30-50 seconds of pumping to get it to start with the engine that cold.

Greg

[imnts2]

Mainepeace Thank you. thank you, thank you very much for all the work and experimenting and talent. I owe you. Not sure what I will do. But I learned a great deal. Your update helps too. I not you still are runing and no comment about repeated maintenance. Wonderful.
Thanks Again
Cheers
lefty2

[mcialien]

reading all this wants me to change my carb scooter to efi.
how does the efi mix teh fuel and oil? my scooter has a seperate tank for oil and fuel. just wondering whether it needs to be premixed or does it have nipple where the original oil line goes into the injection system?
thanks damo

[mainepeace]

You must have a 2 stroke engine. My scooter is a 4t. They DO make EFI kits for 2 stroke engines. Just go to the Ecotrons website. Perhaps I'll start selling kits too. I believe you need to use an oil injector and not use premix anymore, though I do also believe there are injector safe oil mixes now. I don't really have any clue about that, you'll have to contact Ecotrons.

Greg

[mcialien]

thanks greg
just found it on their website, for 299us (~290) aus
the mian thing is with the kit is whether i can get enough money, im 16 and not earning much

thanks damien

[Globs]

I deliberately choose my scooter because it had EFI, as I'm old enough to remember the improvement with cars that it made!

Getting the fuelling spot on for all temperatures and speeds makes a huge power difference, better economy and less chance of damaging the engine from lean running.

In practical use I can confirm that I love EFI, it starts on the first compression and runs the same in all weathers and temperatures.

The fuel pump does take some juice though (not sure about the kit), my Sym shuts it off after 2 seconds if the engine is not running to conserve battery power, and the charger on that is very powerful (headlamps, full power hotgrips + short journeys = a full battery at the end of it).

[mainepeace]

Syms have the advantage of a better charging circuit, which is the hidden problem to Chinese scooters. Most of the time there is enough power from the stator, but if you put on accessories the charging circuit is at a disadvantage.

If you charge up the battery every night it's not an issue. If you don't, expect to replace the battery more quickly.

I would like to fit an HID lamp on the headlight, but that is not going to happen without a much more powerful stator or an external battery setup to do the headlight.

Replacing the bulbs with LED's is the best thing you can do to help the charging situation, short of upgrading to DC and an 11 pole stator, which isn't easy.

Greg

[jeepsteve92xj]

Why didn't I see this thread when it was new? I found the url to this post from the ecotrons.com site where I have visited quite a few times since I got my scooter. There is another very similare kit also from MI, but I can't access the site url from work.

Your details and pictures are awesome.

I have the Xingyue ITA150 wiht 16" wheels. There isn't a lot for performance do to it being another variation of the 150cc G6Y that doesnt share enough such and sleave and head for boring kits.

A day spent installing and a couple weeks of tuning would be more enjoyable than fracking with the carb for jets and stuff.

One small note about the level of the pump needing to be above the injector - granted it is a small relatively low pressure/volume pump - but in cars and trucks, the pump has no problem pumping up hill and many feet to supply multiple injectors.

I believe my tank has a return port for vacuum that should suffice for fuel.
I already added a manual petcock - the one Bluefront had recommended.

I have no idea wht the exhaust pipe diameter is for either your 50cc or my 150cc. I would love to know the optimal size for performance, which should also = FuelEconomy especially with EFI.
I think If I were to keep the stock pipe as you did and add the bung, maybe a 2 or 3 inch section of a slightly larger pipe with the bung would help clear the restriction of the O2 sensor protruding into the small pipe. Like a short expansion chamber.
I may do that with mine to allow the sensor location to be checked for clearance before being welded. Until I get a pipe upgrade.

I don't expect wheelies, but holding 50mph (or more) up a hill and getting 70+mpg doing it would be sweet.

The Honda SH150i and the Suzuki Sisteen are both with 16" wheels and liquid cooled and both Fuel Injected. Both have spcefications with nearly double my aircooled 150cc's power and fuel economy listed into the 80's.

Has anyone found where to even see prices on that Delphi componants/kit mentioned early in this thread?

Steve

[imnts2]

Hey. Great upgdates.

[imnts2]

Greg. Are you still running this scoot. Have you hear if any one else has had your persistence it getting it working? especially on larger scoots.

Thanks
lefty2

[mainepeace]

It's my daily rider. I haven't ridden it much in the past month but I did take her for a spin two days ago. Took a bit to start, about 10 seconds, because I didn't charge the battery and it was a bit low.

I would love to see what an EFI does on Larry's stroker!

So far it's running perfectly. Amazing power with the cold weather. It was about 48 when I rode her.

So far I have not heard from others who have run the EFI system, but I know they are out there as they are selling lots of units.

Greg

[imnts2]

Great. Ain't that great. Compared to CArbs and there headaches. Gosh , I wonder how a 150 would run with it. The problem is that most 150's would not safely handle much more than 55 MPH. I think even an ECharm runs into it's rpm limilter at 70mph indicated ( perhaps 65??) and it is EFI from the ground up.
Have a good season

[D-cat]

Just don't exceed the speed rating on your tires. Usually if you have 12 or 13" rims, you're good to about 75 mph. If you have 10", avoid going over 60.

As far as engine rev vs. speed, that what gears are for; if you have the power for it, tall up!

[timk225]

Here's my thoughts:

An EFI project on a scooter may be nice, but is it really practical? How much gas mileage did you gain? Any noticeable power difference?

That O2 sensor is now restricting your exhaust, you might want to have a custom header pipe made in a 1/2" or so larger diameter that adapts into your muffler.

I have seen and done a lot of work on EFI cars that were turbocharged, and I've read a lot about how people custom tuned their systems on certain automotive forums, like turbododge.com and turbo-mopar.com.

Look into the MegaSquirt fuel management system, it is fully customizable and can be programmed from a laptop computer, they have a great reputation and advertise that they can even MegaSquirt a chainsaw engine, so a scooter shouldn't be a problem. MegaSquirt has been around for years.

I see a LOT of failure points in that EFI system. Lots of things that can go wrong. And for a 50cc scooter? Just learn how to tune a carburetor, change jets if needed, and read the spark plug. It isn't that hard.

And you used RTV to seal the return fitting into your gas tank? Not good. RTV silicone isn't compatible with gasoline, it'll swell up and get gooey. Better check that.

[mainepeace]

The RTV is fine. It's on the outside of the fitting, used as a sealant and not as a glue. Obviously the best way is to get a new tank with a return fitting on it, but I went the cheap route. I could have also put in some brass plumbing fixtures that would seal up nicely but there is the issue of the seat bucket fitting.

This EFI system is MUCH BETTER than MegaSquirt. It is much more configurable and easier to use. I have posted before on the fuel mileage. This winter I have not ridden that much so I'm still on the same tank of gas I put in last November. The point of the EFI (or any mod for that matter) is to have fun with it and not do a cost/return analysis. Sure I'd get more fuel economy with the EFI, but I'd still do it if I LOST 20 mpg, which is what many people do when upgrading to a BBK.

True, the Oxygen sensor is plugging up the exhaust a bit. It's not as constrictive as you may think though. At that point the exhaust gases are still extremely hot and the sensor tip is pretty aerodynamic. Also I was going for the cheap way. Obviously I would replace it on a serious setup.

My point was to get it all working with minimal effort and cost. Working from the ground up I would replace the header. I know I'm losing a bit of top end using the STOCK exhaust and not upgrading. I don't care really as I'm not out for ultimate performance for this scooter. I have a nice 63cc all black scooter that I am going to do some upgrades this spring on.



Greg

[wolfbat3]

So basically Greg this could work on any 50cc scooter if done properly... interest have to keep that i mind.

[justbuggin]

hey greg i am gonna do this upgrade to my 150 in the near future where was it that you got your system

[jeepsteve92xj]

I have to do my Xingyue 150cc , and hopefully also do my soon too arrive Zhen 150cc.
I messed with my carb enough last summer for a lifetime.

I've watched the prices of the kits from two sellers and sadly they aren't going down.

this one that Greg used:
www.ecotrons.com/Small_Engine_EFI_kit.html

and this:
www.mbe-motorsports.com/catalog/product_info.php/products_id/190

I am just starting to look around mbe parent site:
www.chinese-parts-canada.com/turbocharger_fuel_injection.html

With the EFI Honda, Suzuki, Aprillia, Piaggio, Genuine, and CFMoto scooters I am surprised that there aren't more Chinese EFI scooters and kits.

[justbuggin]

thanks i have emailed ecotron today and matt lee replied we are in the starting gate for a 150cc 157qmj efi coversion

[mainepeace]

No, the MBE-Motorsports one is a totally different kit. They use different software and a different ECU.

I used the Ecotrons one. I cannot speak for the MBE quality as I have not used that kit or seen it in use.

It will work the same on your 50cc as on my 63.

Matt is a great guy and he will work with you to get YOUR scooter working with the system. They are constantly upgrading the firmware with new settings as they are always researching.

The reason there aren't EFI kits for most Chinese scooters is that most people who buy the scooters aren't willing to spend $3-400 on a kit to upgrade it when the scooter itself is $600. Most people look at the cost/benefit analysis. You are NOT going to save money overall by going with the kit, unless you keep your scooter running for 10 years as a daily rider, and that's what most people focus on. You WILL get a more reliable scooter with much better power and cleaner emissions and a minor MPG bump.

Greg

[warriorboxerdog]

I was wondering what does your charging systems put out? Mine is 7 amps at 12 volts which equals 84 watts. Does the kit perform well other then the electrical problem? How did it hold up over time? Did you see any performance gains such as throttle response or higher top speed? How good was the tuning software? Did you get any of the upgrades besides the usb port? Has anyone used there cdi? How did that perform? Any words of advise? I'm thinking of getting the 2 stroke version for my 50 cc 2t

[mainepeace]

I have never measured it, but it's a standard 139QMB stator. The "electrical problem" isn't really an issue as I charge up the battery on the tender anyway. It's a good idea to do that to keep the battery in good working order.

As for performance, you should read the thread. I have MPG and MPH specs listed somewhere. Not much on top speed as top speed is a function of gearing, but I can go well over 50 mph radar verified.

Greg

[D-cat]

Did you get 84 Watts on the DC output? That's impressive.

According to the manual, the 50cc stator is rated for 144W at 5000 rpm. That's total AC and DC, and that matters because the 50cc rectifier is half wave and dumps the extra to ground. DC effective voltage is 2/3 AC and at half wave means only about 1/3 total power is available for DC charging, or 48W (4A @ 12v). The lighting tap is AC, is set to account for the effective voltage difference so under normal draw they don't heavily affect each other, leaving in theory 88W for lighting (all 72 of the negative wave, plus the extra third of the 48). This includes both headlights, tail light, all dash lights, and the autochoke. If either circuit exceeds its allotment, it will affect the other in available power, so for just the headlights it should be kept under 50W. This is why you may have your headlights go dim when you hit the brake light, regardless of how fast your engine is spinning.

Now this is just managing normal draws as engineered. Adding an EFI would require increasing DC capacity, or at least reducing AC draw. Reducing other draws should help significantly, such as LED tail light and flashers. There are whole other threads on headlights. I think this thread has shown at least for just EFI this is enough.

Another option might be to convert to full wave AC-DC, giving 96W DC draw available, but no AC (ignoring the exciter coil, unrelated circuit). Rewinding your stator and installing a new rectifier, then rewiring the harness are all good rainy day projects. You'd still want to use LED where possible since overall capacity would be reduced, but management should at least be more straight forward, especially when adding DC loads such as an electric pump for EFI and/or HID.

[mainepeace]

Personally, I think it's overkill, converting to a DC circuit. So much easier to just put in a larger battery and keep it charged, like I did. If you're worried about the "greenness" of it all, get a solar charger.

Of course, people love to tinker and modify, so for them it might be fun. For me it's a PITA as I can't ride my scooter when it's apart. (Of course I do have a dozen I could choose from, but that's a separate issue).

Greg

[subukiit]

Anyone has any idea about this kit that how time it will take to reach in India...coz m gonna order this EFI KIT..

[mainepeace]

It might actually be quicker for you, since it ships out of Taiwan! It took about 1 week (can't remember exactly) to receive it from Taiwan for me. They shipped it out the day I ordered it.

If I were to guess, it would take about 2 days to get to India from Taiwan, but I have no idea how reliable the transportation is going in that direction from Taiwan.

Greg