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Hi, Have a Kawasaki KX250 with a ecotrons two stroke efi turbo kit. Has any one else fitted one of these kits? Having problems getting it tuned right. Starts really well and on bitimun once you get past the bogging it really flies but once on sand or dirt it runs very lean. Despite advertising turbo two stroke kits Ecotrons dont seem to know a lot about tuning the EFI to suit and auto tuning with the 02 sensor hasnt helped. i tried manually tuning but that was worse. If someone has got one to work I would like to hear from them and wouldnt mind trying their Cad file. I know it wont be perfect for my set up but it should put me in the ball park.

I did ask Ecotrons toput me in touch with someone who has got one to work but they just put me in touch with their tech department.

 

 

 

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I dont know a lot about efi & turbo's but you might want to check out some of the snowmobile forums like Snowest.com as the mountain guys are running EFI Turbo 2 strokes a lot. Do a search and maybe make a post on there as there is a lot of info to be had. I hope this helps you.

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to the OP ,

 are you just running the efi system ?

not a turbo charger ?

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On 6/12/2017 at 8:45 PM, Rockiv said:

Hi, Have a Kawasaki KX250 with a ecotrons two stroke efi turbo kit. Has any one else fitted one of these kits? Having problems getting it tuned right. Starts really well and on bitimun once you get past the bogging it really flies but once on sand or dirt it runs very lean. Despite advertising turbo two stroke kits Ecotrons dont seem to know a lot about tuning the EFI to suit and auto tuning with the 02 sensor hasnt helped. i tried manually tuning but that was worse. If someone has got one to work I would like to hear from them and wouldnt mind trying their Cad file. I know it wont be perfect for my set up but it should put me in the ball park.

I did ask Ecotrons toput me in touch with someone who has got one to work but they just put me in touch with their tech department.

 

 

 

have you got the 02 sensor connected and ecu connect to a laptop so you can see what air/fuel ratio is at the rpm that it bogs at ?

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Sure did, it did improve on the bitimun but seemed to make no difference when on the sand.

 

 

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Hi, I am running a turbo and the efi. Will add some pics soon

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on sleds its often clean up the ground and strain the fuel on the way into the tank and replace the in line fuel filter yearly.

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Hi havent had time to get new photos but here are some photos while I was working on it. The plastic tank has been replaced with an Alloy tank, Had to shorton the tank to fit the oil pump and throttle body in,  the plastic welder tried 5 times to stop it leaking but after a week it would start leaking again.

Its A KX250 engine with a KDX250 gear set, heavy duty clutch and clutch basket.

KDX250 cylinder head with the low compression head gasket.

KDX Flywheelwheel with 70 watt charging coil.

Has a Plenium chamber 2.2 times bigger than the engine to keep a charge inbetween strokes.

Uses a primary turbo off a twin turbo Subaru, Runs 7lb boost and boosts up suprisingly quick.

Next time I try this I will ask the doctor to borrow his Tardus to try and fit everything in.

The bike has been made for beach racing and has been lowered 100mm.

Pic1.jpg

Pic2.jpg

pic3.jpg

pic4.jpg

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Can't see your pipe but there has to be a enough backpressure in it from the turbo and pipe diameter to control charge loss. Another strategy is to use another reed cage for the intake to the sealed airbox.  Your problem could be a lot of things though.   As boost builds fuel has to increase and timing decrease, if your controller has preset curves for normally aspirated you might need to come up with your own.

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Hi, Highmarker. I am using the origional stinger pipe out of the exhaust. Holding boost does not seem to be a problem. You could be onto something about the ignition timing. I did retart the timing but I may not have retareded it enough as I am using the standard KX250 CDI.

The main problem I am really having is trying to get the Ecotrons injection system to stop running lean. I can watch the oxy sensor reading on the fly and its scary how lean it gets. Ill retard the timing a bit more and try a few things in the next couple of weeks. Will keep you posted.

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Did you ever try an eco Trons kit without turbo?

definitely an interesting build, there are only so many variations of bike builds but you just made something different. Keep it up!

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When you say run lean, does it happen at a certain RPM, only under boost, @ what boost level, etc?! In general, 2-strokes are notorious for running lean in the mid-range so don't be too surprised if you're adding lots of fuel compared to the base map. What's the fuel pressure @ from the pump? Do you have a return line or are you returnless? Do you have a rewound or hi-output stator to handle all the electrical demands? Thanks for sharing, interested in the details on this one!

 

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RawbW Hi, never tried the injection system without the turbo, if I wanted to do something by halfs I would ride a 4 stroke, ha ha.  

317 Hi, thanks for the interest. It seems to run rich until the turbo kicks in then lean. Running a 40lb fuel pump with the ecotrons fuel regulator, extra fuel goes back into the tank. The KDX250 lighting coil is replaced with an aftermarket 70 watt unit. Its been changed from a half wave to a full wave stator then goes through a resistor/regulator to a 4 amp battery. It charges at about 14 volts. Once when the regulator stopped working and the battery voltage got low it actually flooded as the injectors cant close fast enough. It has two injectors, a small one for idle, then the main injector kicks in above idle and when the turbo boosts the small injector comes in again as a boost.

As a note I have tried playing the global fuel inrichment setting (riches the fuel by a selected percentage over the whole rev range) just to see what happens when the turbo kicks in and its ok then suddenly floods at about 7000 rpm and I assume thats when the small injector kicks in. Must be a very fine line line between being too lean or rich.

Hopefully Ill get a chance to do some testing this weekend.

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Think I see one problem that would cause it to run lean under boost. Fuel pressure regulator should be manifold, or boost referenced. The Ecotrons regulator does not appear to have the reference line. As pressure rises at injector tip, so should supply pressure. Without the increase of supply pressure your effective pressure across the injectors decreases. 40psi. fuel pressure spraying into a intake with 7psi. Equals a actual working pressure across injectors of 33psi. 

Same scenario can happen if injector tip is exposed to vacuum, but in reverse. More manifold vacuum = higher pressure difference across injectors. Opposite of what the engine wants.

You might be able to tune for this, but it would be a whole lot easier to not have to tune for the reduction in effective fuel pressure under boost.

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Sand generates the highest load on the engine and the highest boost.  I would add fuel in on the high load map cells.  I assuming its a 3d table for fuel and ignition.  You just need to identify which cells on the map its running through when its leaning out and add fuel accordingly.

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Jeremyf1 Hi, thanks for the input I dont think that that is the problem as the fuel pump has more than enough capacity to easily keep up the injectors. In saying that I might just do a fuel pressurer test on the fly as I have been wrong many times before.

Turbo Dan, Hi, yes it does do a 3D graphic of the mapping and I have tried doing that but without too much success, the Ecotron O2 sensor set up for two strokes does not show up very well on the ecu recordings, its like they added it as an after thought. You can either record what ther ECU is doing or what the O2 sensor is doing you cant record both at once to get a good picture of whats happening. Its only because it comes with a display that I know how lean it actually is (and by the detonation sound from the engine). I think I will need to make a rolling road so I can make changes on the fly.

Thanks

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