900r ignition coils

[Gosling1]

good to hear you found the problem keep an eye on the reg/rec output now for a month. If the battery was dry, chances are the reg/rec output could be high - this is what boils batteries dry. Having an AGM battery is good but eventually this will also fail if the charging voltage is much over 14 to 14.5 volts....15v absolute maximum.

Checking charging voltage is as easy as putting the voltmeter across the battery at idle - charging voltage at idle must be 13.8 minimum. Give it a rev out to 4k - charging voltage should rise to 14.5-15v. Any higher - especially anything over 16v - the reg/rec is stuffed and should be replaced.

[lotii10396]

Gos you must have been sending brain-signals.

Had a chance to go for a dull 1hr run this week, it was hot & sunny riding up to Nuri and the same gremlin happened - although not severe enough to stall the bike, instead just make it run like crap riding into town. New battery & coils obviously help but the core problem is still there. Drove home later that evening, virtually exactly the same run (revs, speed, distance, etc.) but no gremlin. Only difference was cooler ambient temp (bike temp stays the same day or night for highway running) which is apparently enough difference for the gremlin not to occur. Touchy obviously!

One of the observations I have with this gremlin is that when the symptoms are described every mechanic says it is fuel. God I hope not.......!

I have just checked the charging voltage with a replacement IC Ignitor box (Ron @ crystalcreek did me a good price - again!) I was trying to get a handle on what the output voltage should be when read your post, esp. re: dry battery = overcharging. I had measured charging voltage previously and it was only reading 13.5V (which is Kawasaki spec) so I was wondering if 14.5V might be too high - but it seems like it's OK as long as <15V.

However charging voltage doesn't change with revs - it stays absolutely solid at 14.5V - ???

You are spot on keeping an eye on the alternator - the IC box shouldn't make any difference on charging voltage but something has changed. Alternator (I'll just replace the lot) definitely the next part under the spotlight - not that there's much else left

[Gosling1]

good luck with it mate, I hope you get it sorted soon

Old-school method of checking the battery is charging properly - turn the lights on and give the bike a rev. The headlight should brighten noticeably. If the headlight just stays exactly the same - it's generally a charging circuit problem (reg/rec or alternator windings on the way out).

[lotii10396]

Mmmm, as mentioned revving makes bugger all difference. Got myself a little digital voltmeter & I'll wire this in to watch see, but the alternator has already had a sentence passed on it - spare ordered! Alternator problem does fit (as does IC box) , as it is all cylinders that are affected & new coil/battery reduce effect but don't eliminate. It's been a tricky little gremlin to sort but I'm not unduly fussed - I actually like tinkering with the bike and gives me an excuse to replace bits anyway. The bike is just wonderful & I love riding it: so it will be a keeper.

[lotii10396]

Update:

Yesterday went for 30km hwy ride on hot day with spare IC box and voltmeter. Volts 14.3 in town and steady at 14.4-5 on hwy. As soon as I came off hwy revs into Mt Barker bike started to lose power and volts were down around 13.8. I planned to head home via Strath but as I left Mt Barker volts dropped away totally, meter reading 12.5 (ie less than battery!) and bike splutters to a halt. 5min on roadside and going again, but it was stop-start riding as run time gets less and less, had to stop three more times to make the 30km back home.

The two main observations are that the volts are fine when starting ride & they stay steady at hwy speeds, so its a hard one to troubleshoot as there are no signs of the problem until you slow down. When its running crap fuel is almost pouring out the exhaust.....so its not a fuel starvation issue!

Spare alternator installed this arvo, wet so haven't ridden but volts steady at 14.5. FYI spare is same part number but slightly different - uses a thicker o-ring (only noticed cause swapped over the 'new' one and it didnt fit) and the cover is cast aluminium rather than pressed steel of the A8. All fits fine though.

Hopefully this sorts it - but need a warm day to test....c'mon summer!

[Bike-Nut]

I may have the answer for you.
My A1 suffered the same symptoms a few years back but due to the length of time i have owned it i knew it wasn't coils. Mainly as you pointed out there are two of them.
Also suspected the igniter but had another niggling suspicion. Confirmed it was not the igniter by borrowing the one off my dads GTR.
This confirmed the suspicion. It was the pickups on the crank position sensor.
On the end of the crank is a plate which has a tab which passes a hall effect sensor (pickup) which signals the igniter.
Was a lot cheaper than an igniter box also.
Symptoms were exactly as you describe so it sounds like the issue to me but i could be wrong.

Hope it helps.

[Gosling1]

^^^^ deffo worth checking the igniter coils to see if they are in spec........

Years go on the Pearl, I had a mis-fire which started out of nowhere one afternoon, just as I was about to ride up to Sydney to watch one of the first Formula Xtreme days.

I rode to the closest mechanic which happened to be Bruce at Macquarie (local ACT members will know who I am talking about..)

anyway, his apprentice had a listen.....and then said 'lets take the points cover off'- he then used a screwdriver to just tap lightly on the igniter coils - sure enough, he tapped - and 1 pair of plugs stopped working altogether and the bike almost stalled. Tap again - and running on all 4 just fine. He reckoned that the igniter coils fail like that due to age/heat and number of cycles. Got a spare set from his box of parts - and on my way

[lotii10396]

Sorry for delay in responding - family etc. So a closing summary.

Replacement alternator seems to have sorted the ignition issue. Like everything once it's sorted it kinda makes sense and the breadcrumbs add up, but the symptoms made it incredibly hard to explain to a mechanic because it runs fine when I'm there or its being serviced.....so most think it fuel related.

- not a misfire, but the whole engine just completely loses power and splutters to a halt
- only happens when hot, need to let bike cool down to get running again. Worse in hot ambient conditions.
- only initially happened when running at a constant highway RPM (but got progressively worse)

It does seem like fuel, but if this is discounted then the alternator does seem an obvious culprit - and it does get hot. The over-charged battery was a big clue and the voltmeter really tells the story. Thanks to Gos who pointed that out. The fact that it occurs across all cylinders at the same time means that if it were coil failure (ignition or ignitor) than it would have to be both coils failing at exactly the same time. Possible , and Ignitor coils were next on the list BTW!

Anyway I now have a spare IC Box (handy) and with new ignition coils and leads bike starts and runs so much better. So good in fact that I no longer bother to run 98 fuel (thats all previous owner used) and the sound? Pure bliss.

As an interesting comparison my car recently had a similar running issue, no mechanical fault, starts and runs fine but no power up hills. After all the standard checks (spark, fuel, exhaust) the mechanic thought MAP sensor but a new one, new plugs, new coilovers etc. didn't fix it - instead made it worse! So bad it was un-drivable, so thought the only next option was to discount the ECU - and like the bike not especially easy finding a secondhand one to test the theory. In the end it turned out to be a catastrophic internal failure of the cat - which was less than 2 years old & didn't make any rattles.

A lesson I have learnt is that IC boxes and ECU's *can* fail, but in some ways the increased complexity of engines makes me forget to really look hard at the basics. If the bike had an alternator light (like most cars & probably modern bikes) I'm sure this would have lit up and I would have immediately looked at the alternator. And Kawasaki discontinued the alternator check function for the A8

All fun and games, learnt more about the bike and a big thanks to all that helped.









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[pkay]

I just read this cause my 900 is the bane of my life - every time I fix something, something else fails. The previous owner really stuffed the bike up with home mods so unwinding these has been a challenge. And just when you thought it was all good the replacement switchblock was for a two cable not one, and the stone you pulled out of the radiator actually blocked a hole (glad it didn't come out on a ride). Needless to say seeing what you went through to chase down the problem has kept me in the game

[HeyCharger]

Hi guys. I'm an old codger who has just purchased his 2nd GPZ900 ( after a gap of some 25 years .
I want to replace coils and leads (Plugs are already on their way).
I see I can get TourMax coils from the UK for 30GBP ea,
Can I also get leads and what do you suggest?
I also need small trinkets like air filter, front indicator, mirrors and foot brake light switch.
Thanks. Rod.