Fuel injection on the two stroke

resetjet
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resetjet 10/16/2014 8:15am
10/16/2014 8:15am
Also, not sure why, but it seems KTM falls under different rules being in austria then the japs as far as getting 2T bikes green sticker.
O___o
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O___o 10/16/2014 8:19am
10/16/2014 8:19am
resetjet wrote:
First of all fuel inject and direct inject are entirely different. No reason to complicate what works good with a carb.....waste of money. Only real reason...
First of all fuel inject and direct inject are entirely different.

No reason to complicate what works good with a carb.....waste of money.

Only real reason to do DI is EPA compliance.

Boats did it for that.

Snowmobiles mainly due to cold weather and high altitude and big changes in both on the same ride.

Somewhere there is a KTM inteview where the guys says they have a DI bike on the shelf, but see no reason to put it out as it will cost more, be more complicated and break easier and a carb does quite well on a 2T motorbike.

So until the EPA bans carbed 2 strokes, don't get your hopes up.
KTM has a FI bike. They are waiting for "someone else to release it first to see how it does." That is what this is, and I believe Sherco shares technology with KTM. I see this as possibly having gone down as a "good for hte goose, good for the gander" situation with KTM letting Sherco in on the FI bike technology, so Sherco gets the technology and the risk, and KTM gets the guinea pig.

and why put radiators on a bike when fins cool them just fine?

endurox
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endurox 10/16/2014 8:48am
10/16/2014 8:48am
resetjet wrote:
Also, not sure why, but it seems KTM falls under different rules being in austria then the japs as far as getting 2T bikes green sticker.
MX bikes racing on a mx track will have to conform to new CARB rules unless the CA. riders start to raise cane.
So A1 in 2017 the bikes will be running ethanol 91 octane if CARB has there way.
ando
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ando 10/16/2014 10:42am
10/16/2014 10:42am
O___o wrote:
KTM has a FI bike. They are waiting for "someone else to release it first to see how it does." That is what this is, and...
KTM has a FI bike. They are waiting for "someone else to release it first to see how it does." That is what this is, and I believe Sherco shares technology with KTM. I see this as possibly having gone down as a "good for hte goose, good for the gander" situation with KTM letting Sherco in on the FI bike technology, so Sherco gets the technology and the risk, and KTM gets the guinea pig.

and why put radiators on a bike when fins cool them just fine?

They're actually waiting to see what the 2017 emissions regulations look like. It's in an interview that one of the head technical guys at KTM did a year or so ago.

The Shop

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ando
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ando 10/16/2014 10:45am
10/16/2014 10:45am
resetjet wrote:
First of all fuel inject and direct inject are entirely different. No reason to complicate what works good with a carb.....waste of money. Only real reason...
First of all fuel inject and direct inject are entirely different.

No reason to complicate what works good with a carb.....waste of money.

Only real reason to do DI is EPA compliance.

Boats did it for that.

Snowmobiles mainly due to cold weather and high altitude and big changes in both on the same ride.

Somewhere there is a KTM inteview where the guys says they have a DI bike on the shelf, but see no reason to put it out as it will cost more, be more complicated and break easier and a carb does quite well on a 2T motorbike.

So until the EPA bans carbed 2 strokes, don't get your hopes up.
Agreed.

DI two strokes are not the panacea that everyone thinks - most of the advantages that a regular two stroke has disappear with DI systems. As you said, things like weight, complexity, cost.
peelout
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peelout 10/16/2014 10:49am
10/16/2014 10:49am
a little birdy told me direct inject will come on the 2016 KTM's

i'm crossing my fingers, but i'm not entirely convinced. i've been hearing a similar story for Honda, but Honda has shown their lack of giving a fuck towards 2-stroke owners.
Skerby
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Skerby 10/16/2014 12:20pm
10/16/2014 12:20pm
I read like the first four posts, and I know you are all dying to hear my opinion.

Here it goes, new yz250 run so good out the box, never touched the carb and I rode that sucker everywhere.

My experience with injected 4 strokes is that the FI system is like a carburuerator(spelling is hard) with one setting that cannot be adjusted without an expensive tool. Fuk'n kawi ran real lean and there was nothing I could do about it besides throwing a towel in the airbox.
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Markee 10/16/2014 1:11pm
10/16/2014 1:11pm
loftyair wrote:
You can come jet my bikes everytime I go riding at different altitudes or swing in temps and humidity levels then...thx. It will make more power...
You can come jet my bikes everytime I go riding at different altitudes or swing in temps and humidity levels then...thx. It will make more power, it's more efficient, and it will save gas, therefore costing less to operate.
CamP wrote:
So I should pay $8k for my next 2T because you can't jet a bike?
Yeah no shit.

My biggest complaint for a 4 stoke is weight. Adding weight to a 2 stroke, i'm not a fan of that. If advances in fuel delivery on the 2 stroke can be had with minimal weight added, i'm down.
YZ125H1
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YZ125H1 10/16/2014 4:20pm
10/16/2014 4:20pm
The system used on the Honda EXP-2 would be cool, but Honda has a patent on it which will never see the light of day. Much easier fix than creating a DI system.
ando
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ando 10/16/2014 6:11pm
10/16/2014 6:11pm
loftyair wrote:
You can come jet my bikes everytime I go riding at different altitudes or swing in temps and humidity levels then...thx. It will make more power...
You can come jet my bikes everytime I go riding at different altitudes or swing in temps and humidity levels then...thx. It will make more power, it's more efficient, and it will save gas, therefore costing less to operate.
CamP wrote:
So I should pay $8k for my next 2T because you can't jet a bike?
Markee wrote:
Yeah no shit. My biggest complaint for a 4 stoke is weight. Adding weight to a 2 stroke, i'm not a fan of that. If advances...
Yeah no shit.

My biggest complaint for a 4 stoke is weight. Adding weight to a 2 stroke, i'm not a fan of that. If advances in fuel delivery on the 2 stroke can be had with minimal weight added, i'm down.
Don't be under any illusion - a DI two stroke that meets emission regs WILL be heavier, more complex and more expensive than existing machines.
ando
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ando 10/16/2014 6:14pm
10/16/2014 6:14pm
Skerby wrote:
I read like the first four posts, and I know you are all dying to hear my opinion. Here it goes, new yz250 run so good...
I read like the first four posts, and I know you are all dying to hear my opinion.

Here it goes, new yz250 run so good out the box, never touched the carb and I rode that sucker everywhere.

My experience with injected 4 strokes is that the FI system is like a carburuerator(spelling is hard) with one setting that cannot be adjusted without an expensive tool. Fuk'n kawi ran real lean and there was nothing I could do about it besides throwing a towel in the airbox.
I'd say you had a dud fuel injection system.

The real problem for two strokes trying to meeting emission regulations is not the carb but the way the scavenging and charging works. That's where the engineering difficulties lie.
bama205
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bama205 10/16/2014 7:59pm
10/16/2014 7:59pm
EPA ruins everything. Damn libs
Berm
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Berm 10/16/2014 8:12pm
10/16/2014 8:12pm
The e-tech DI engine for Ski doo snowmobiles is almost a $2,500-3,000 premium over the carb version.
Anthony Siracuse 10/16/2014 8:32pm
10/16/2014 8:32pm Edited Date/Time 10/16/2014 8:32pm
Sorry for the double post
c_dub
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c_dub 10/16/2014 11:25pm
10/16/2014 11:25pm
Metering rod carbs (APT and Lectron) are the holy grail for two-stroke MX bikes in my opinion.

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Vecchia Scuola 10/17/2014 12:05am
10/17/2014 12:05am
I am sure the injection plus a good hardware would solve the very last problem of two stroke wich is traction on hard pack.
After that,good bye farter!
Wink
deenamathew 10/17/2014 3:54am
10/17/2014 3:54am
The way fuel-injection differs from a carburetor is that fuel is atomized due to being forced through a small nozzle using high pressure in fuel-injection. While the carburetor relies on low pressure created by intake air, drawing the fuel into the air-stream.
O___o
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O___o 10/17/2014 5:06am
10/17/2014 5:06am Edited Date/Time 10/17/2014 5:55am
I'm going to post the solution, so everyone can ignore it and argue about something else.

Keep the carburetor on the two-stroke. They need a TPS. (which most already have) The trick is in the ignition. However, a multiple map ignition is needed in conjunction with the TPS. It would only take 2 or 3 ignition maps. What you do is calibrate an RPM threshold, and in conjunction with the TPS the CDI could "see" wheelspin when the RPM threshold shoots up to the upper pre-designated limit, then retard the curve back to one of the other 2 or 3 milder ignition curve, until a condition of traction exists, at which point it would revert back to the original, most aggressive timing curve. Example: TPS maintains a constant 100% value (wide open) but RPMs shoot from 6,000 to 9,500 without load increasing (wheelspin condition) the CDI would bump back to the milder map(s) until the TPS value and RPMs indicate a traction condition.

It would be seamless to the rider, you'd never feel anything (other than dead-hook traction out of corners) and you get to keep the carburetor, albeit with a TPS (which most of the newest 2-bangers already have)

the possibilities with a system like that are virtually endless. It would still be closed loop, could be programmable by the user if they were competent. data logging capability would show you exactly where you are getting wheelspin and on which map(s) the wheelspin was occuring and the user could dial in ignition retard/advance accordingly. a bar-mounted switch could be used to over-ride the system on starts.

if an electric powervalve servo is used, ala RC valve Honda or electraction TM, one could integrate the motion of the powervalve into the system for further traction and linear power delivery. I won't try to convert anyone though, i'll just do it myself and ride it. Ride what you want.
Johnny Depp
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Johnny Depp 10/17/2014 8:33am
10/17/2014 8:33am
Direct injection should have at least these benefits:
*more power by better atomization and placement of the fuel charge
*better mpg by better atomization and placement of the fuel charge
*less emissions by better atomization and placement of the fuel charge
*better power delivery by more tuning choices
*the ability to eliminate pre-mixing by oil injection

Now the downsides:
cost
weight
complexity
reliability
dirty fuel problems
do it yourself mechanics are out
software for programming
racer628
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racer628 10/17/2014 1:39pm
10/17/2014 1:39pm
only one problem...its built in france.
queen of spodes 10/18/2014 5:30am
10/18/2014 5:30am Edited Date/Time 10/18/2014 5:30am
O___o wrote:
I'm going to post the solution, so everyone can ignore it and argue about something else. Keep the carburetor on the two-stroke. They need a TPS...
I'm going to post the solution, so everyone can ignore it and argue about something else.

Keep the carburetor on the two-stroke. They need a TPS. (which most already have) The trick is in the ignition. However, a multiple map ignition is needed in conjunction with the TPS. It would only take 2 or 3 ignition maps. What you do is calibrate an RPM threshold, and in conjunction with the TPS the CDI could "see" wheelspin when the RPM threshold shoots up to the upper pre-designated limit, then retard the curve back to one of the other 2 or 3 milder ignition curve, until a condition of traction exists, at which point it would revert back to the original, most aggressive timing curve. Example: TPS maintains a constant 100% value (wide open) but RPMs shoot from 6,000 to 9,500 without load increasing (wheelspin condition) the CDI would bump back to the milder map(s) until the TPS value and RPMs indicate a traction condition.

It would be seamless to the rider, you'd never feel anything (other than dead-hook traction out of corners) and you get to keep the carburetor, albeit with a TPS (which most of the newest 2-bangers already have)

the possibilities with a system like that are virtually endless. It would still be closed loop, could be programmable by the user if they were competent. data logging capability would show you exactly where you are getting wheelspin and on which map(s) the wheelspin was occuring and the user could dial in ignition retard/advance accordingly. a bar-mounted switch could be used to over-ride the system on starts.

if an electric powervalve servo is used, ala RC valve Honda or electraction TM, one could integrate the motion of the powervalve into the system for further traction and linear power delivery. I won't try to convert anyone though, i'll just do it myself and ride it. Ride what you want.
Wheelspin is half the fun of riding a two stroke. Cheap is the other half.
resetjet
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resetjet 10/18/2014 5:47am
10/18/2014 5:47am
Everyone knows FI results in more horsepower, etc.....However, power is not the 2 strokes problem. It has plenty of it. Wheelspin and powerband is the problem. (i am a 2T lover BTW, so save it)


The pic of the KTM 125 with the DI system is starting to make sense. Maybe they can get the power of that thing up enough to justify it. Not that it would compete with a 250f, but what the heck.


All I know is that investment into R and D for the 2 stroke is a good thing for me, however it comes. I can always continue to ride my old bikes if I don't like it.
Question
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Question 10/18/2014 5:51am
10/18/2014 5:51am
resetjet wrote:
Everyone knows FI results in more horsepower, etc.....However, power is not the 2 strokes problem. It has plenty of it. Wheelspin and powerband is the problem...
Everyone knows FI results in more horsepower, etc.....However, power is not the 2 strokes problem. It has plenty of it. Wheelspin and powerband is the problem. (i am a 2T lover BTW, so save it)


The pic of the KTM 125 with the DI system is starting to make sense. Maybe they can get the power of that thing up enough to justify it. Not that it would compete with a 250f, but what the heck.


All I know is that investment into R and D for the 2 stroke is a good thing for me, however it comes. I can always continue to ride my old bikes if I don't like it.

I though DI would bring more torque since it is a 44mm vs a 36-40 carb. I can be totally wrong, I just always felt more diameter = more torque... but I am far from being a carb guru Smile )))
TMV
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TMV 10/18/2014 8:01am
10/18/2014 8:01am
Question wrote:
I though DI would bring more torque since it is a 44mm vs a 36-40 carb. I can be totally wrong, I just always felt more...

I though DI would bring more torque since it is a 44mm vs a 36-40 carb. I can be totally wrong, I just always felt more diameter = more torque... but I am far from being a carb guru Smile )))
I think there's a limit. You can put any carb size that fits but at a point there's a saturation point and no gain anymore. I'm not 100% sure so if someone could confirm it....
nytsmaC
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nytsmaC 10/18/2014 8:21am
10/18/2014 8:21am
I like that my 2-strokes have no battery, no fuel pump, no complex wiring harness, no extra fluff. A minimalistic, simple bike that is cheaper to buy, cheaper to maintain and quick/easy to work on. No laptop required.

I won't consider buying an EFI 2-stroke until they are significantly better than a carbureted one. Even then it will be with a lot of reluctance as all of the things I stated above will be gone never to return.

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