Fuelling Fix
 

DISCLAIMER: YOU DO THIS AT YOUR OWN RISK AND MAY VOID THE MANUFACTURERS WARRANTY.

Step 1. Before turning the ignition on press and hold Select and Reset buttons, turn the ignition on and keep holding both buttons until you see the Diag screen appear.

Step 2. Press Select once to toggle to the CO MODE

Step 3. Press both Select and Reset together. Hold for about 3 seconds to enter co mode. The number displayed is the cylinder selected (genereric computer for all Yamahas) You need to select 1, Press select to scroll up and Reset to scroll down.

Step 4. Press both Select and Reset simultaneousley for a few seconds to see the setting for the selected cylinder. This number will be different on every bike and has no relationship to the mixture its just a number it can range from -128 to +128. Write down the number and keep it in a safe place in case you need to return to your original settings.

Step 5. Pressing select will increase the value (richen the mixture), pressing Reset will decrease it.

I initially increased my setting 5 digits from 10 to 15. This smoothed the bike out but still had a little surging. After reading what Alan and others have said it should be safe to increase your original setting by up to 10 digits. I will now adjust mine up another 3 to 18.

Step 6 To exit CO mode, turn off ignition.

Noticed benefits. The bike is now very smooth to ride and on my 1st adjustment took out almost all the surging/jerkiness. This has made the bike much easier to ride through corners where i can now get on the gas earlier in the corner increasing the mid corner speed.


More info can be found on the forum: fueling fix.

fueling fix
 

I have been playing with the fueling on my Xt660X to improve it's performance & rideability.

I have fitted variable adjustable resistors to the Air temp sender & Coolant temp sender. Adjusted them to lower temp readindgs, of 5 deg C for both. Increased CO from 9 to 28. Adjusted throttle angle sensor from 16 to 22. Removed the snorkel from the airbox & added 2X 50mm holes to the airbox. I still run STD pipes.

The bike rides very smooth now, with a little improvement throught the whole range & not much more in fuel. This might help other riders who can't afford a power comander or local Yamaha dealership that can't get your Xt to run smoother or stop it cutting out.

Seems like you sorted your bike out well, it cost me a fair bit of dosh to get mine sorted ! did you have any problems with the bike cutting out,another of our members has this problem i thought it could be the throttle sensor?

Fueling fix
 

My bike cut out from the very day I bought it. I took it back to the agents a few times, they had no clue what the problem was, that was a year ago. It was very intermittent.

I then started to do a little research on the fuel injection system. I found away to richen the CO through the dash & moved the throttle sensor up in angle & never looked back. No more cutting out

The bike still ran very lean. A few weeks latter I then played with the Temp sensors. Add two variable resistors & that richen it up nicely.

I have also made 2 spacers for the front fork springs, as I have found the front end starting to sag. Spacer size 37mm outter, 25mm thick, with a 20mm hole in the center. The front end feels nice & stiff & has not topped out with the extra spring tension.

Hi kev!

Nice one there. Looks like you have managed to outrun the system with that trick.
It looked almost like one trick we used to try on the Golf GTI 16v. There you have a full throttle switch, wich we runned over a relay with a sertain resistor connected to it so it was fooled to belive that the engine was cold and opened the coldstartvalve. But only when you pushed the pedal to the metal:icon_cool:

Please let us know how you did it and wich ohm you used for the air and coolant temp senders so that others could try it

Nice mod

Fueling reply
 

Hi Stoppstadd

I left the motorcycle trade as a mechanic after 12 years & now have work for Volkswagen for the past 14 years. As a workshop foreman. I have been playing with fuel injection systems for a few years now. So the Xt was pretty easy to sort out.

I used 2x. Adjustable resistors from 0 Oms to 1k Oms, rated voltage 50VDC & 0.8 watts. You can get them from you local electronics shop.

I cut the Coolant temp wire green/red in half, just below the fuel tank. Ran two wires from the variable resistor to each end of the cut wires & joined them. IE, the resistor between the cut wires. I did the same for the Air temp sender. IE, the resistor between the cut wires.

I then went in to the dash into zone 5 & 6, then adjusted the Air & Coolant temp sender deg C & found after may hours playing. The best variable for my bike, being 5 degs C below the actual reading. I can turn the resistors to 0 Oms & the bike is back to STD for work, good fuel consumption. Then can adjust the resistors up, in turn lowers the temp deg C, for the weekend mountain racing. I have marked the resistors 5 & 10 degs settings, for quick adjustment. I had already adjusted the CO up some time before I carried out this mod.

Great!

Another easy way to fool the injection system.

I dont need it becauso of the PC wich i quick adjustable manually if you want to richen the mixture. But maybe for someone who wants to save a buck its worth it.

I have not worked with VW but im a audi/ VW freak and i have owned about 20 golf cars and several audis over the years but my favourite is still the audi UR quattro -81 a silvercoloured one that i had 10 years back. Had to let it goe because of military duty:093: I still miss it...

Good work/ information ther kev!

Kev, that sounds very interesting and I am sure our members might find it extremely useful on their bike, however is there any chance you could take some pics of the step-by-step operation so we can publish it here and call it the KEV-MOD?

See what you can do. Thanks a lot for the tip

Fueling fix photos
 

Fueling fix photos, of Air & Coolant sensor wiring. Red wiring for Coolant temp adjustment, yellow wiring Air temp adjustment.
Also warm the bike to operating temp before setting the variable resistors.

Hope it helps someone.

Kev

Excellent work Kev, later I will make this a dedicated thread called the Kev Fuelling Mod.

Kev,
Thanks to let us know about your investigation.
Did you make this modification because you still have the Old ECU or does it works for the new one as well?
Thanks
L66

fuel mods n rockers
 

I have a new 06 model xt and so far it has not cut out at all but is rather lumpy I do fing this annoying tho I have a Hyerbusa that is also choppy on the throttle so I guess that its a lot to do with fuel injection in general. I have been interested in the mods mentioned here tho they do sound like common sense to me and I would like to try them on my bike. If I do this for the standard pipes fitted and then change them for something that wont please the neighbours will I have to go through the exersize again ?

I do feel that the stock bike is a bit underpowered, perhaps the engine is really just screaming inwardly to be free'd.

Interested in your comments thanks

mainly the problem with the stock bike is that it has to meet european standards of emission and noise pollution therefore when it comes out of the factory it has restrictions which are there to comply with those parameters, i.e. cat converters in the exhausts, restricted air filtering and ais (air induction system)

So replacing cans with open ones and removing the snorkle plus fitting high flow filters stage 1 & 2 will release the full potential of the bike at the expenses of the environment.

We understand however some problems are present with ecu and tps which Yamaha still hasn't manages to rectify in the XTX/R bikes however I can tell you that the MT-03 has no such problems because on the official Yamaha website it is stated that a newly designed fuel injector has been fitted to that bike and I had it on loan for 2 weeks and can guarantee it works.
I wish that mod could be done to all the new XTX/R but perhaps Yamaha can't be bothered

Ecu
 

Hi Lewiss66

I still have the old ECU. Yamaha in Australia won't give me a new one. Resulting to this mod.

This mod will work on any version of ECU.

I have forwarded a full step by step discription with photo's for fitting this mod to the administrator. He will post it soon.

Kev

Yes people the patented KEV Mod will work on all ecu's and I am going to publish the guide in the techno section soon and thanks to Kev for coming up with this gold nugget :wav:

Hi
one thing you will find in doing all these mods are (apart from making your credit card scream with mercy ) .you will get a better throttle response through the rev range,better mid range power,smoother running engine ,a better sounding exhaust note,you will only gain a minimum higher top speed .
So all in all its a lot of cash for very little gain . If it is power you are after then the way to go is with a different cam shaft or a engine rebore , larger piston .

Important Message For Kev
 

KEV please read and help thanks

Dear Kev I have received your pics and the only problem is my pc won't run the file Fuelling.wps, I understand is a Microsoft word document but can you save it as a .doc document or even a .txt file please and then resend it?
Thank you so much I am dedicating a page on my website just for this mod so I do need the document.
Best Regards
Fran

Just sent it off mate.

kev

got it working on it now Kev, cheers

Fran

Captmoto,

Talking about the MT03, When you say "on the official Yamaha website it is stated that a newly designed fuel injector has been fitted to that bike" It might be interresting to know if the Injector itself is the only part to replace instead of the all assembly. In that case It might be worth replacing that part for the new one instead of buying a power commander + dyno...!
L66

The Kev Mod is here
 

http://www.xt660.com/site/node/53

Looks great mate, well done.

kev

Well thank you for giving us this opportunity, tell me Kev are you any good with washing machines? :toothy9:

just kidding mate

Well done

Ohms
 

What is right ohm value for resistor? Is it 1K ohm as 1000 ohms, or is it 1000K ohms as 1M ohm? CaptMotos KevMod page says 1000K ohm, but Kev at his message says 1000 ohms. I am thinking of testing this mod, and got to be sure witch resistor to buy, I think its the 1K, but please confirm that.

We are going to have to ask Kev, I am afraid, I only published on my website the text and pictures that Kev submitted to me by email. Bear with us and we shall clear / rectifiy the issue asap, Kev is New Zealand and probably in the land of nod at this time so we'll have to wait a little later.

cheers

Sorry for the confusion, it is a 0 to 1k ohm resistor. CaptMoto, please can you correct your Web page.

Thanks
Kev

Thanks guys! That was quite quick.

Hello Kev,
I just wanted to know how you finally get to tweek those two temperature sensors (coolant and intake air). What about the other sensors. Did you play with them as well?
Thanks
L66

Hi Lewiss66

I adjusted my TPS well before this mod, because it was cutting out. I still have the 04 ECU. If you have an 05 ECU you don't need to adjust your TPS.

I had adjusted my CO up to, because it was lean. But this only seemed to help in the bottom end. I need something to richen it up over the whole range. So I played with the Air/Coolant temp sensors.

I am a mechanic by trade & used my experience in helping me to find a happy balance of not to rich & not to lean.
I started with the Air Temp sensor adjusted it down in Temp. Until the bike was to rich, I then turned it back a few DegC. Then adjusted the coolant temp sensor until it started to run rich then turned it back a few DegC. I carried out spark plug checks to check fuel mixture as a guide line, but it's more of a feeling how the bike pulls.

Start in the bottom to mid range, also using the CO adjustment. Once that feels good write down the settings. Now run the bike from mid to near top end ranges. Adjusting the Air & Temp sensors. Write down the settings. Now see if there is any difference in settings & mix them together to get the best result.

This is a basic way of setting fuel injection. If you want the exact science you need a Power Commander & Dyno to set it up. I.E.. Every 250RPM you can make an adjustment & save it to the Map. Remember every engine is different & needs it's own precise tuning. Yamaha mass produce engines with a base tuning spec, lean for emission control. So in most cases you can get your motor to run better, by making it breath better & richen it up.

I would recommend if you are not aquatinted with tuning engines, get some to help you. Or best of all, run it on the Dyno.

Hope that helps.
Kev

Thanks KEV,
Great Job!:038:
L66

fixing it now :066:

Done!

Kev any other gremlin you find a solution for please let us know thanks.

Engine Breather
 

Something else I have done is disconnect the engine breather pipe from the airbox. Blocked the airbox side, fitted a L pipe to the existing pipe, connected a new 13mm ID pipe to the L pipe & routed the pipe down between the swinging arm & the motor. You can get a plastic L pipe from the local hardware shop, irrigation section.

This is so you get pure air into the airbox & not rebreathed engine fumes. Better Air more power.

They only do this for emission control.

Another interesting mod Kevin my old mate, how's about pictures and examples please?
Thanks

[ATTACH] Attachment 190[/ATTACH] The photos, engine breather mod. Don't forget to block off the Airbox after the mod.

Will take home my camera tomorrow, it's at work. Photo's taken by camera phone. Will post clearer photo's tomorrow night.

Kev ,do you know if this mod will have any effect on bikes that have power commaders and bikes that have had dyno runs,or is it a straight forward mod.???

Hi buck.

This mod is for all bikes, no matter what mod it has had.

In theory the purer the oxygen the bigger the bang. Oxygen levels change from city riding to country riding, so this mod really only makes sure you have the best oxygen molecules wherever you are riding.

A motor can only induct a certain swept volume of Air/Fuel usually 14.7 parts of Air to 1 part Fuel in the ideal. So making sure you have the best 14.7 parts of oxygen molecules is the ideal.

I remove my engine breather from the Airbox, for this reason. No use in rebreathing hot engine fumes, when you need cold condensed air for the big bang.

Ok gotcha,i was concerned it might give problems once people have had a dyno set up and doing this mod would result in having to put it through another run to set it up again.

Great! I have also been thinking of doing this mod. Now i got some great ideas of how to do. I was thinking of fitting a filter at first but now i will go for the "L" tube.

But what on earth is that "hose mod" you have done to the air box???? Seen in the middle pic.
You are not leading in unfiltered air are you?!?!???

The hose mod
 

The Hose Mod

Ok, I have been caught. Another mod by Kev.

Back to the Hose Mod. The standard air filter area is 9768mm sq in area. With the snorkel removed from the Airbox, the intake area of the Airbox is 4000mm sq. So the Airbox is restricting the air flow through the filter by more then half, not good.

I drilled two holes 33mm in diameter, one on the right side of the airbox & the other next to the removed snorkel. Then got two L pipes with the ID of 30mm with an extension tube between the L pipes, as seen in the photo & fitted it to the side of the airbox. Away from any water entry.

I also cut the removed snorkel hole bigger from 4000m sq to 5500mm sq. Cut was made in one piece so I can glue it back when I sell the bike. The two holes can also be blocked with 35mm grommets. All parts bought from the local hardware, L pipes from the irrigation section.

The extra air made a big difference in acceleration. More Air meant, more Fuel needed, that's where the Kev variable resister mod came in handy.

I did not want to fit a 2nd stage filter for fear of water entry or water saturation of the cotton in the filter.