[pedroguerra21]

hello to everyone...!

This is about a 2008 kawasaki zx10r, and it will be a good question for the experienced users.

well, it happens that running the bike from 1st to 4th, everything stays cool, no issues at all...

when i am on 5th or 6th gear, if i am revin´it in the highway and hiting top speed as well no trobe at all...

but if i am on 5th or 6th gear and try to cruise like 5000 or 6000rpm, with throttle stay, bike suddenly starts to loose (lack) power like 500rpm and then you feel a pull and it goes back to normal... few seconds later the same thing and so on... rpm´s go down like 500 and them up ...

i thought i had a bad exhaust valve, so i took it off and installed a ESE ( healtech) so the fi does not comes on. bike stays the same...

one more strange thing, is that when i stop the bike i can ear a wisle from the tank and if quickly i open the tank cover it shuts off ...all the tubes under the fuel tank are correctly installed ...

what do you guys think...?

anyone ever pass through this...?

 

[MiamiNinja]

I've experienced that loss of power issue as well but don't know what it is. Sorry i cant help you on this one. Good luck maybe let us know what it is if you find out the issue.

 

[pedroguerra21]

Exactly the same symphtoms...?

 

[pedroguerra21]

Apparentelly from what i am seeing, it seems like this 9×2 oring is not in a good shape and it might be loosing pressure through it and that explains the witsling on thr fuel tank after stopping it.

I will also replace the fuel filter, although kawasaki does not sells this part alone, i have been doing the same on a Gsxr 1000 2007 and find out they are the same.

Any help would be great.

 

[GreenOne]

This is a longshot, but where are you from?

This is a common behavior if you have a euro spec bike with lambda sensor eliminators. At least for the gen 2, but I assume it is the same for gen 3. Happens after about 10-20 seconds on steady low throttle between 0-20% at cruise rpms (0-~7000). Typical highway riding. And only in 5th and 6th. The issue happens when the ecu goes into closed loop. If the stock lambda sensor(s) are not there, the ecu don`t like the lack of feedback from the missing sensors and will continue to richen up afr all down to 11/10:1 range and you will loose power, and rpm will continue to drop. The moment you twist the throttle a little it snaps back to normal.

 

[pedroguerra21]

In fact i am from Europe.
But i do not have o2 sensor eliminators... the stock O2 sensors are plugged into place and working... no fi light on the dash... no service codes...

 

[BOP Leader]

From your description it sounds like you may have a blocked gas cap/gas tank vent tube. Even though the pipes are correctly installed, doesn't mean they may not be blocked. Try blowing compressed air through the lines to clear them.

 

[BOP Leader]

Also, have you riding at a constant 5-6krpm in any other gears? Could be a bad throttle position sensor

 

[GreenOne]

In fact i am from Europe.
But i do not have o2 sensor eliminators... the stock O2 sensors are plugged into place and working... no fi light on the dash... no service codes...

Ok, it`s probably not the issue then. The stock o2 sensors are unlikely to fail.

However...the sensors could still malfunction without triggering any FI light. (at least for gen 2) As long as the heater element circuit in the sensor is not broken you will not get the FI, even if the sensor part is faulty. That`s why the o2 eliminators don`t work for anything else than getting rid of the FI light. They only close the heater element circuit. And that`s also why dynojet made the o2 optimizer later.

If you have a PCV on the bike you can datalog the injectors duty cycle/pulse width and see if they richen up the bike when the issue happens. Just to rule out faulty o2 sensors. I can tell you how.

Which brings another issue to mind. If you do have a PCV with stock o2 sensors in place and a single map for all gears, you can experience similar issues. In this case you must make an advanced gear map and zero out the closed loop area for 5th and 6th gear. (Connect and sync speed sensor or connect gear position sensor first).

If you have the issue in any other gear than 5th and 6th it is something else.

 

[pedroguerra21]

Also, have you riding at a constant 5-6krpm in any other gears? Could be a bad throttle position sensor

Yes, i have. No loss of power... no "flutuations" on the rpm... 1st, 2nd,3rd, 4th bike runs just great... 5th and 6th gear if i cruise like 5k or 6k rpm steady throttle it starts bogging... feels like your fuel is going end and then she wakes up... but if i run full throttle no trouble at all ( although i feel like she is not giving all that she can )

 

[GreenOne]

Also check for exhaust leaks before or around the O2 sensors.


Sent from my iPhone using Tapatalk

 

[pedroguerra21]

From your description it sounds like you may have a blocked gas cap/gas tank vent tube. Even though the pipes are correctly installed, doesn't mean they may not be blocked. Try blowing compressed air through the lines to clear them.

This sounds for me the most reasonable explantion... however from what i can see at dealers manual, there is a fuel tank for usa Canada and florida with an external return hose... mine does not as i am from europe...

But in faction i have a problem with pressio or suction at the fuel tank...because as i am riding if i get close the fuel tank i can ear the "whisling"...

Today i have mad an inspection to the fuel pump and found out a faulty oring ... replaced it and run it on the stand with strady throttle at 5k rpm and no losses... (i am running out of time as the day goes by ) i can not confirm the problem is this because with the bike on the stand you have a free wheel so...

By monday will bet back to you...

 

[MiamiNinja]

yes the exact same thing. Happens every now and than but havent had it happen in a little while.

Exactly the same symphtoms...?

 

[BOP Leader]

There will be a vent on your gas cap to allow air in to occupy the space left behind from fuel leaving the tank. Fuel starvation will cause the symptoms you describe.

 

[BOP Leader]

To verify if you have a vent issue on your tank, use your spare key for your bike and crack open the tank while you cruise in a straight line in 5th-6th gear. This will verify if you have a vent issue.

 

[pedroguerra21]

There will be a vent on your gas cap to allow air in to occupy the space left behind from fuel leaving the tank. Fuel starvation will cause the symptoms you describe.

I understand your point, and of my first tests was blowing compressed air into the cape hole, and it vents all the way until the hose under the fairing...

So, i really can't assure if it is a pressure or a suction issue...

 

[pedroguerra21]

So... today...

Went for a teste rife on her.
Bike starts easier, i think this is due to the replacement of the faulty oring and i will go ahead for the fuel filter replacement ( same as Suzuki Gsx-R 1000 2007/2008, 29eur at portugal ).

Anyway the problem is still there...

However i received the de-cat pipe at the end of the day and while i was installing it i saw the catalitic converter had like 5 holes all arround... honestly i don't think this could cause the problem, but who knows... tomorrow will be riding it and let you know...

So, resuming, bike has not trigered any fault codes... i think it has not that kick it would have... 5th and 6th gear bike "swallows" rpm cruising low speed arround 5k or 6k rpm...

My new theory is that Somehow someone has attempted to flash the ecu with a non-recomended driver or not properly... what i feel is that for a small amount of tps, the STP close itself and that causes the symphtom like when you are without gas or engine breaKing... and so i will step forward and will analyse the ecu maps...hope to come here soon but i expect to take 2 or 3 weeks to get my job done.

Thanks

 

[GreenOne]

Does this look familiar? Notice throttle position. (time in seconds and speed in km/h)

 

[GreenOne]

However i received the de-cat pipe at the end of the day and while i was installing it i saw the catalitic converter had like 5 holes all arround... honestly i don't think this could cause the problem, but who knows... tomorrow will be riding it and let you know...

If you bought a true decat link pipe you have a gen 2 registered in 2008? Gen 3 cat is part of the header.
Holes in the cat should not cause the issue. Although it tells the story of somebody messing with the bike.

My new theory is that Somehow someone has attempted to flash the ecu with a non-recomended driver or not properly... what i feel is that for a small amount of tps, the STP close itself and that causes the symphtom like when you are without gas or engine breaKing...

This should not be possible with the given circumstances. I mean, it is of course possible to (by error or not) reprogram stp to close at a certain throttle position/rpm, but it should happen the moment you are in that range and not appear after steady throttle.

I still think it sounds like a closed loop issue if your description is accurate. Any other non electronical issue should present itself in 4th as well as the load is next to identical at cruise.

 

[pedroguerra21]

I am preparing to show you closelly what is happening... i think that untill the end of the day i can edit the clip