.: XT660.com - The #1 XT660 Resource :.

.: XT660.com - The #1 XT660 Resource :. ( https://www.xt660.com/index.php)

- Fuelling and Intake ( https://www.xt660.com/forumdisplay.php?f=207)

- - Fuelling Fix ( https://www.xt660.com/showthread.php?t=55)

Quote:

Originally Posted by Stoppsladd

Ahaaaa!!

Now i understand. But i didnt think that a thing like that would affect that sensor. What do you think of the fueling mix now? Will it go richer now because of the lower pressure or is it the opposite way?

Not quite sure, a good question. Would have to think about this one, my first thought is leaner as you shut off the throttle. As the pressure sensor is also a load sensor & would read a lower pressure when the throttle is closed.

All I know it does make a marginal difference.

Quote:

Originally Posted by lewiss66

Hello Kev,
Last point about this modification.
Don't you think that puting a filter instead of a L hose at the breather engin hose end would be a safer solution to keep the particles from getting into the crancase chamber?
L66

Yes I do think putting a filter is a great idear, as long as it is the sealed type, .IE. plastic fuel filter so it won't get the cartage wet.

Make sure it is at least 12mm ID, as not to restrict the engine breather.

There is already a flutter valve in the oil trap of the XT's, so not to worried at the moment.

Haven't done mine yet, not found a filter of that size. Will fit one once I find one.

kev,
I talked to a friend about that modification. He own an old XT500 and knows a bit on mecanics. He said that the engine breather is connected to the air filter in order to spread some oily steem coming from the engin pipe. This will avoid the filter to dry up that can cause even more problem to the engin after around 2000miles. What do you think of that?
Putting a T pipe from the engine breather connected to the air box for one branch and down to ambient pressure for the otherone would might fix it up.
L66

Quote:

Originally Posted by lewiss66

kev,
I told to a friend about that modification. He own an old XT500 and knows a bit on mecanics. He said that the engine breather is connected to the air filter in order to spread some oily steem coming from the engin pipe. This will avoid the filter to dry up that can cause even more problem to the engin after around 2000miles. What do you think of that?
Putting a T pipe from the engine breather connected to the air box for one branch and down to ambient pressure for the otherone would might fix it up.
L66

Hi L66

The STD air filter on the XT660 is a paper element, I'm sure you would not want any oil or oily vapor to contaminate the paper, once the filter is full of oil/vapor the air would not be able to pass through the paper element.

If the XT660 was designed for the engine breather to lube the air filter, I'm sure they would have fitted a foam type filter.

To my knowledge Euro 2 Emission Control states engine vapor is to be rebreathed & not vented to the atmosphere.

I would not vent the Airbox down steam of the filter, because it would suck in dirty unfilted air.

Kev

How about removing the airbox completely and replacing it with a small conical gauze type one.all the air you need and no need to re-route pipes.
http://www.mandp.co.uk/list.aspx?tie...rs&tier3=S%26B

Quote:

Originally Posted by Kev

Hi Kev,
I agree but what about Filters like the K&N filter.That's what I have fited. It's got oil inside and removing oil/vapor in the air box might dry it up and damage it.
I'll check with K&N compagny if that can cause problems.
L66

Quote:

Originally Posted by lewiss66

I don't see any problem using the K&N filter with the engine breather disconnected, as it fits in the exact same position as the STD one.

The STD one does not get any oily/vapor on it with the breather fitted to the airbox. If you are getting excess oil on the filter the engine has blow by & there is a problem with the engine.

The air flows through the air filter & the breather is down stream, can't really see how it would get to the filter in the XT660 design unless there is a engine problem.

I have owned 2, XT500's, first one in 1981. That motor used to blow allot of oily vapor into the airbox, it had a round oil trap which did not work to well & had a flat type foam air filter.

If you wheelied it to far, it would dump about 300ML of oil from the engine breather straight in to the airbox & smoke as if it was on fire. In those days I modified the engine breather to the top of the frame into a thin plastic bottle with another pipe out of the bottle back down below the motor. I would empty the bottle ever so often, manly because of wheelies.

Quote:

Originally Posted by Buck

Super bikes owners have been doing this for years.

The only thing with fuel injection you have a few things to consider. You would need to fit the Air Temp sender & Pressure sender into the design, may be a short tube between Throttle body & Filter.

You would have to calculate the swept volume of the cylinder in cubes, stroke/bore X 8000rpm. To work out what size air filter would be needed. This is normally worked out on a flow test bench.

For us a bit of trial & error.

For the latest info on the Fuel mod, check this thread http://www.xt660.com/showthread.php?t=356

[QUOTE=Kev]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. Just remember that the coolant temp sender is for the fuel injection & the cooling fan. So don't set the temp sender for the coolant sender to any setting below 5 deg C mark, then you will be safe. You can adjust the air temp to any setting. I had already adjusted the CO up some time before I carried out this mod.

Quote:

Originally Posted by JMC

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.

If your bike still suffers from surging after this fix please contact your yamaha dealer, more info can be found on the forum: fueling fix

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

My XT vibrates a lot when you crank the throttle open. My C1 was at -6 I have moved it up to 0, this has smoothed it out quite a lot. Do you know if there is a default initial setting or is this a factory set-up on assembly?

Also where can I find a "map" of the diagnostic menu's, info and adjustments?