Tank Slap - Motorcycle Forum

Yes it does Duke.

I'm wondering if the coils are starting to fail when they get hot and then work again when they have cooled. Apparently this can be quite common when a coil is failing.

That or vapour lock in the fuel whe it's very hot but I wouldn't have thought so tbh.

I wondered about the coils as they do break down as they get hot when on the way out. Check all the cables to them as well.

Have you got a Power Commander fitted, Blade?

Cabling to the coils checked a thousand times Duke.

Yes I have a power commander. Dealer hasn't asked me to remove but then maybe he is not aware I have one. Perhaps I should mention it and see if he wants me to remove that as well. I guess that way at least it's stock.

Thanks very much for the input which is appreciated buddy

Ok power commander and exhaust valve elimnator now removed. Bike now has no NON OEM electronics installed what so ever.

Whilst the bike was stripped down I also check the resistance for the primary and secondary windings on each stick coil. As to be expected all within range but guessing / wondering if these could go out of range when hot ? So not 100% confident the coils can be ruled out.

Come in for some lunch before the disappointment of a test ride to verify no further forward

One bonus is I can now strip a zx10r blind folded probably quicker than a kawaskai Mechanic the amount of practice I've had. In fairness it's a very easy bike to work out and well put together which is welcome with current events.

Kwacky wrote:
If it's not a sensor I wonder if something is warming up and letting in air? Only reason I ask is because I've had this in the past with a car. There was a small seal which started to crack. When it was warm it let in air and caused the car to idle badly and sometimes stall.

Dunno if you've given this any thought but it's the only thing I can think of now.

Kwacky wrote:

Kwacky wrote:
If it's not a sensor I wonder if something is warming up and letting in air? Only reason I ask is because I've had this in the past with a car. There was a small seal which started to crack. When it was warm it let in air and caused the car to idle badly and sometimes stall.

Dunno if you've given this any thought but it's the only thing I can think of now.

Cheers Kwacky I have and was one of my first checks to inspect all hoses for split or damage. Also checked the vent pipes from the tank weren't pinched anywhere and help creating a vacuum and vapour lock to the fuel on very small throttle openings when hot which in theory could cause a vapour lock and stall scenario.

Appreciate the suggestion and help though mate, thank you.

May have made some progress today fingers crossed.

Need to do more tests but looks potentially better although don't want to say fixed yet.

Will update tomorow after more tests.

duke63 wrote:Have you got a Power Commander fitted, Blade?

Duke your a star . Looks most likely it was the power commander or the exhaust servo elimnator as since removing both I have done 100 trouble free miles alot of which were ridden in the conditions most likely to generate the random fault I. E. Stop start traffic with a hot engine temp.

I doubt it was the servo eliminator as even if that throws a code it won't shut the engine down.

However the power commander controlling the fuel injection MAY have given the Code 31 vehicle down sensor as the on board self diagnosis obviously wouldn't be looking for power commander faults. My theory is code 31 was the nearest it could get to a power commander fault although WILDLY misleading and set me off down the complete wrong track in faulting finding. Also kawasaki were doing the same and looking at code 31 fixes. Very misleading.

I did change the power commander map a week ago in an effort to help the problem so the thing still works. All I can think is the signal was changing as the cabling got hot and this generated the fault and shut the engine down.

At the moment I m just mighty relieved my bike is not dead. Next step is to refit the exhaust servo eliminator back on the bike as its a 2 minute job and will prove which of the two items I removed on friday was causing the problem i.e the servo eliminator or the power comannder.

I'm also going to call the manufacturers and see if they have heard of this technical fault previously.

Strange thing is the power commander worked faultessly for 7000 miles and the issues only started shortly after the QS and servo elimnator were installed admittedly very randomly. Could be a huge coincidence or possiblely either the QS or the Servo Eliminator have influenced or generated a problem with the power commander.

Any suggestions ?

I can't remember what QS set up you had. Did it interact directly with the PC?

I'm no expert but these things are always a process of elimination and the easier it is to disconnect something, the sooner it can be eliminated or found to be the issue. Sometimes its easier when its not your own bike to as it takes the personal aggro out of the equation.

Doing an internet search its appears QS and PC compatibility is very hit and miss. One item is cutting the ignition and or fuel to enable an upshift whilst the other is trying to optimize the fuelling for best running. I would guess that if one isn't aware of the other then this could sometimes cause issues.

Possibly that was the issue as prior to installing the QS the PC was faultless. However I'm not 100% convinced as it worked faultessly everywhere in the rev range except at idle when hot. Good info though thanks Duke.

It was a PCV and Translogic IS4 QS I had installed Kwacky.

What threw me and kawaskai off course for a good while was the disgnostic both on board and the workshop based system flagging code 31 vehicle down sensor fault which would have explained the engine cutting out if it had been a TRUE diagnosis and not a complete red herring and very misleading.

One thing I have noticed is the bike idles much much better since the PC has come off. Previously it would hunt on idle especially when hot. I didnt notice this before the problem occured so I m assuming the idle was ok prior to QS install as I m very observant and also would have check the idle when servicing. I didn't think much to this as the idle is governed electronically with no manual adjustment and when I compared with Rockets Zx10r his bike was identical and hunt on idle when hot and he doesn't have a PC fitted. With hindsight this must have been part of the issue.

Big thanks to everyone who has helped it really has been appreciated and good to exchange ideas and suggestions which have helped massively. Thank you guys

If it hadn't been spotted Kawasaki would have charged me a fortune in labour for fault finding only not to cover it under warranty as a third party item was at fault.

It's been very frustrating but being positive I've learnt some stuff along the way which is always very good. Especially electrickery which has never been my strong point

It's pretty much the best possible end to this tale of woe, really.

Can you make anything back off the Power Commander or is it fubar?

I will do some more tests Itchy but the PCV is working and you can change the fuel maps and there is no obvious damage to control unit or connectors.

I think it's just not compatible with my QS tbh.

Happy days!

Blade wrote:I will do some more tests Itchy but the PCV is working and you can change the fuel maps and there is no obvious damage to control unit or connectors.

I think it's just not compatible with my QS tbh.

if that was the case why did it still cut out after you removed the quickshifter

Happy days any way Glad its sorted

Now that is a very good point Rocket. Cheers buddy its very good information and something I hadn't considered.

At least the QS looks to be OK which is good news as I can put it back on and I'm glad as I loved it

Or possibly it was the servo elimnator which I can't rule out yet. If I was a betting man I would say PCV. However it's a quick an easy check to put the servo elimnator back on and see if there is any negative effect so I will do that when I get 5 minutes and at least I will then know one way or another if it was the PCV.

I'll also ring Dynojet UK and discuss the issue with them as maybe they can shed some light on the situation.

The good thing is its now fixed but I would still like to know the exact ca use if possible. Just for learning and peace of mind if nothing else as this fault really did baffle me.