Bigger Fuel Injectors For Ninja 250

[Powerband]

With cars its possible to install bigger injectors to accomodate other modifications to match fuel flow....to increase power without having to reprogram anything.

Are there any injectors that are bigger and would fit the 250 ninja?

Maybe this is why so many consider the 250 ninja underpowered?

Anyway to increase the flow of fuel injectors?

doing a wiki for fuel injectors after this.

[dave_boo]

Simply using bigger fuel injectors probably wouldn't work for increasing power unless they were crazy bigger. If you haven't changed the fuel pump, there's a chance that the pressure would drop (disregarding stuff I'm going to talk about in a second) due to the fact that the path is now less restricted. Also; what would the ECU do? Even assuming that the pump could keep the same pressure, it would lower the opening time of the injectors to maintain its programming.

So, if you went really big to the point that the ECU couldn't make a correction to the lean enough to offset all the extra fuel in, and the pump was keeping up; what good does that do to you over getting a power commander and doing it right?

Shoot...you could just unplug the lambda sensor and get more fuel in the cylinder....

[Richard-BKK]

Replacing the 8-hole INP-288 fuel injectors with something bigger will very likely result in a negative effect. A fuel-injection system doesn't work on the bigger the better, if somehow you can decrease the fuel-droplet size in the fuel-mixture will keeping the fuel and air mixture at the same level you will see a good increase in performance.

[submaniac]

Ditto with what everyone else said. Bigger injectors alone won't do anything. I am sure you can get other injectors, with a higher flow, but without some kind of engine management system to accommodate the injectors and adjust the air fuel ratio, the bigger injectors will not do anything, and may decrease performance if anything else. Engines will actually produce more power per each piston firing, if there is less fuel in the cylinder (and more air). The manufacturers, for the sake of safety, err on the side of putting too much fuel in the cylinder rather than risk destroying an engine (and paying under warranty) if the a/f ratio gets too thin. You would at the very least need an engine management system like a power commander to dyno tune with the new injectors.

[LivinLOS]

ECU controls fuel flow rate, not (only) the injectors.

[Richard-BKK]

@LivingLOS, actual on fuel-systems as used on the Kawasaki Ninja 250R the ECU only controls the time the injectors can spray fuel. The ECU doesn't to check or regulate anything else as the pressure of the fueling system is constant at 43psi and the resistance of the fuel-injectors is about 11.7 to 12.3 Ω

The (2010) fuel-pump of the Kawasaki 250R is far over the specifications needed for the its fueling-system, changing the size of the injectors to something bigger would give no problems to the fuel-pressure. The fuel-pump can pump 17mL for a period of 3 seconds...

[LivinLOS]

@LivingLOS, actual on fuel-systems as used on the Kawasaki Ninja 250R the ECU only controls the time the injectors can spray fuel. The ECU doesn't to check or regulate anything else as the pressure of the fueling system is constant at 43psi and the resistance of the fuel-injectors is about 11.7 to 12.3 Ω

The (2010) fuel-pump of the Kawasaki 250R is far over the specifications needed for the its fueling-system, changing the size of the injectors to something bigger would give no problems to the fuel-pressure. The fuel-pump can pump 17mL for a period of 3 seconds...

So whats the fuel sensor bung on the exhaust measuing for then ??

I understood lose the bung and it over fuels and burns the engine to hel_l ??

[Richard-BKK]

If the sensor in the exhaust system is not properly attached (or removed), the ECU can see this as the combustion is not getting enough fuel-mixture and the ECU will keep the injectors longer open to fuel the combustion. This has not much to do with the flow-rate of the fuel, the fuel-flow-rate is at all times the same.

[VocalNeal]

Powerband,

Is the 250 available in the US? You could check with Techlusion they make a unit for 650. As 250 is also a twin it might be suitable.

Instructions do say if 02 sensor is fitted it should be removed.

[LivinLOS]

If the sensor in the exhaust system is not properly attached (or removed), the ECU can see this as the combustion is not getting enough fuel-mixture and the ECU will keep the injectors longer open to fuel the combustion. This has not much to do with the flow-rate of the fuel, the fuel-flow-rate is at all times the same.

So the sensor and ECU control the fuelling.. The ECU sends more fuel (technically same flow rate but longer times.. Same effect).

I would not have thought the ECU can control the amount that passes through the injector, thats a physically limited thing no ??

[Richard-BKK]

@LivingLOS yes the fuel-flow is limited by two factors the fuel-pressure (43psi) and the resistance of the fuel-injectors.

The ECU opens the “door” and closes the “door”, the only variable is how long the “door” stays open...

On high-end race machines the fuel-pressure is also regulated, as fuel-temperature, air-temperature and engine-temperature can create a to high tolerance in resistance off the fuel-injectors.

[Richard-BKK]

Double post sorry

[LivinLOS]

@LivingLOS yes the fuel-flow is limited by two factors the fuel-pressure (43psi) and the resistance of the fuel-injectors.

The ECU opens the “door” and closes the “door”, the only variable is how long the “door” stays open...

On high-end race machines the fuel-pressure is also regulated, as fuel-temperature, air-temperature and engine-temperature can create a to high tolerance in resistance off the fuel-injectors.

Right.. So thats exactly what I said.. its the ECU that controls the fuelling..

[monty]

Apparently the injectors can deliver a fair bit more petrol then what the engine can burn.

My friends Ninja has an AreaP exhaust along with a power commanderIII and the oxygen sensor disconnected.

Lots of extra power with stock fuelpump/injector.

Not cheap though!

[Richard-BKK]

I have a friend, not sure he still has his Kawasaki Ninja 250R, who saw reindeer on his roof with a guy dress in a red mantel...

[monty]

I have a friend, not sure he still has his Kawasaki Ninja 250R, who saw reindeer on his roof with a guy dress in a red mantel...

?????

[Richard-BKK]

Sorry Monty,

I not believe that disconnecting the oxygen sensor will help in performance. The PowerComander III does help, but I was told it even depends more on the sensors then the original ECU (mainly because it is closer to the edge of what is possible and therefore even need to know better what the atmospheric conditions are.

[dave_boo]

Apparently the injectors can deliver a fair bit more petrol then what the engine can burn.

My friends Ninja has an AreaP exhaust along with a power commanderIII and the oxygen sensor disconnected.

Lots of extra power with stock fuelpump/injector.

Not cheap though!

Oxygen sensor (lambda sensor) is disconnected at Power Commander's instructions. In fact they brag they can provide up to like 100% more fuel when using their module.

Sorry Monty,

I not believe that disconnecting the oxygen sensor will help in performance. The PowerComander III does help, but I was told it even depends more on the sensors then the original ECU (mainly because it is closer to the edge of what is possible and therefore even need to know better what the atmospheric conditions are.

It doesn't. But the Power Commander is slightly 'dumb' in that it doesn't use O₂ readings and base it's maps on that, but rather just adds fuel above and beyond what the ECU says to put in....

[katabeachbum]

To get more power I would not touch injectors. They have enough capacity, and larger injectors gives lousy idle and low rpm power.

1. Remove cat and bypass Lambda (co2 sensor telling ECU to reduce fuel to injectors when exhaust is to dirty).

2. Block EGR

3. Spend more cash, Power Commander or individual ECU tuning

[Richard-BKK]

@monty, sorry, you are right... the PowerCommender III recommends removing the oxygen sensor.

@dave_boo, guess I need to read the manual more often...

[dave_boo]

@monty, sorry, you are right... the PowerCommender III recommends removing the oxygen sensor.

@dave_boo, guess I need to read the manual more often...

I'm a voracious reader...and for all the crap I give you often you are correct...so keep the chin up.

[Richard-BKK]

Hi Dave,

I not care that much about what people thing about me, I'm just me... If I'm wrong I'm not afraid to say...

For most things I said, time will tell, remember a few years back you questioned if Kawasaki will even introduce the motorcycle you ride today...

[Bard]

When you reach the level of tuning to injectors, have you done the exhaust yet, the cams yet? Have you ported it yet? Done a vaccum test? Dyno with power commander?

Anyway when you done all that (cost more than a Ninja 250) the Injectors can be worked with, will they do much? No not really unless you overbore the cylinders.

A wise man said, you want to upgrade the power? Maybe you upgrade the bike, it's normally cheaper and the bike is easy to fix. A 400 or 600 is cheaper if you sell the 250, than upgrade to the level of injectors.

Cheapest way to upgrade power is to lessen the weight, remove passenger pegs, lighter tires, remove all you don't need, replace with lighter weight. You over weight? Loose it. 10 pounds is 6 bhp on a typical 100 hp bike, on 33 hp it is much more.

Anyway I like to fool around with engines, but screwing around with injectors is not necessary unless you dramatically change either the cc of the bike or rpm. It's a waste of good money.

[dave_boo]

When you reach the level of tuning to injectors, have you done the exhaust yet, the cams yet? Have you ported it yet? Done a vaccum test? Dyno with power commander?

Anyway when you done all that (cost more than a Ninja 250) the Injectors can be worked with, will they do much? No not really unless you overbore the cylinders.

A wise man said, you want to upgrade the power? Maybe you upgrade the bike, it's normally cheaper and the bike is easy to fix. A 400 or 600 is cheaper if you sell the 250, than upgrade to the level of injectors.

Cheapest way to upgrade power is to lessen the weight, remove passenger pegs, lighter tires, remove all you don't need, replace with lighter weight. You over weight? Loose it. 10 pounds is 6 bhp on a typical 100 hp bike, on 33 hp it is much more.

Anyway I like to fool around with engines, but screwing around with injectors is not necessary unless you dramatically change either the cc of the bike or rpm. It's a waste of good money.

So how many kg/kW is that?

I think that's the biggest problem my 'lil ninja has...my fat ass...

[katabeachbum]

When you reach the level of tuning to injectors, have you done the exhaust yet, the cams yet? Have you ported it yet? Done a vaccum test? Dyno with power commander?

Anyway when you done all that (cost more than a Ninja 250) the Injectors can be worked with, will they do much? No not really unless you overbore the cylinders.

A wise man said, you want to upgrade the power? Maybe you upgrade the bike, it's normally cheaper and the bike is easy to fix. A 400 or 600 is cheaper if you sell the 250, than upgrade to the level of injectors.

Cheapest way to upgrade power is to lessen the weight, remove passenger pegs, lighter tires, remove all you don't need, replace with lighter weight. You over weight? Loose it. 10 pounds is 6 bhp on a typical 100 hp bike, on 33 hp it is much more.

Anyway I like to fool around with engines, but screwing around with injectors is not necessary unless you dramatically change either the cc of the bike or rpm. It's a waste of good money.

So how many kg/kW is that?

I think that's the biggest problem my 'lil ninja has...my fat ass...

I find it easier to get a bigger bike than to loose weight

[Powerband]

So it seems this bike is limited by the sensors that calculate fuel delivery is all.

Who's done the actual modifications, except for te cat removal, i've never seen any gains by removing a cat, it just gets louder, at a loss of low end.

[visions]

Just curious...anyone ever tried an electricly driven supercharger on a bike. Easier to fit, (than belt drive) not a great power robber, and can easly vary the boost available, and switch off if not required. Bike basicly remains standard. I know they have been used on cars with very high HP gains, but never seen anything about them on bikes???

Maybe there is a reason my limited knowledge has hidden??

[soundman]

Just curious...anyone ever tried an electricly driven supercharger on a bike. Easier to fit, (than belt drive) not a great power robber, and can easly vary the boost available, and switch off if not required. Bike basicly remains standard. I know they have been used on cars with very high HP gains, but never seen anything about them on bikes???

Maybe there is a reason my limited knowledge has hidden??

GIYF.Here.

[Powerband]

An electric supercharger would probably have to work in burst and not a constant air charge. There wouldn't be enough electricity to keep it going all the time.

if you feel the exhaust gas coming out of the muffler, you would have to atleast have that much input to get a return.

[visions]

An electric supercharger would probably have to work in burst and not a constant air charge. There wouldn't be enough electricity to keep it going all the time.

if you feel the exhaust gas coming out of the muffler, you would have to atleast have that much input to get a return.

Yes. Been doing a little research and apparently the amperage draw is very high requiring big leads (very)etc. Usually a 24 or 36V motor. Also of course the charging capacity of most bikes wouldnt keep up with the drawdown loads imposed with a constanly running unit.

Seems always.... the real answer is to buy a bigger capacity bike, but of course lose the economy and manouvability of the smaller bikes. Both important considerations in urban driving.