ZZR1100 C won't start - any other thoughts?

[darkyoung1000]

Morning all,

I rode said dinosaur to work yesterday after approximately 6 weeks off the road.
It was a bit grumpy to start, but no more than I'd expect it to be starting up after 6 weeks.
Ran fine - as usual really for 12 miles and then parked up.
Came to start my Easter weekend with a ride home... and it wouldn't start.
Battery is fine, plenty of cranking power
Full tank of fuel (and I can smell from the exhaust it's getting fuel) to the cylinders.

I'm going to do the following:
Check the kill switch wiring
Take the plugs out and check for condition and actual sparks.
If ok, check the valve clearances.
If ok, check compression.

I've had other thoughts about the CDI unit but not investigated further.
Bike is (I think) relatively standard, with 60,000 miles. Alarm/immobiliser was removed some while back.

Any other thoughts on what I've missed to check? This can include 'why not just set fire to the bloody thing' which was mostly my thoughts having pushed it round the corner 1/4 mile uphill to the motorbike shop yesterday...
Cheers,
Tom

[Plinth]

My Bandit 12 refused to start because of the sidestand cut out switch (?) was faulty.

[anonymous-user]

side stand kill switch?

[Pope]

Flooded?

Got to be worth a go:

Throttle wide open and crank it over for 10 seconds; if there is any sign of firing keep going.

[podman]

If you left the bike with a full tank over Winter, thats quite a lot of weight bearing down on the fuel system, after that sort of mileage/wear, the fuel tap may have given up the ghost, fuel then can bypass the needles/seat and , as suggested above, flooded the whole thing.

Ive had to replace the taps on both my RDs to stop this problem, my 350 would only start with a bump in the end..

[Rubin215]

Check for sparks first; spare plug, plug lead off, ground against head.
No sparks means check clutch and sidestand switches before moving on to ecu etc.
Sparks means fuel issue such as a stuck float-valve causing flooding.

[neutral 3]

Check for a spark first. ZZR1100 body work is a bit fidly and time consuming to take off, if you havnt worked on one before.
The C model ZZR1100 is quite scarce now.

[steve954]

Sounds like the problem I had on mine!! Battery dead!!
You say it's cranking over fine but that doesn't rule out the battery!!!! All it means is the battery is taking all the power to crank over but not enough to fire the spark plugs!

Try a jump pack or jump leads before anything else!
It's a easy thing to try first! What do you have to lose?

[darkyoung1000]

Thanks all, some useful suggestions there, sidestand switch especially. It's played up in the past, but the other way - allowing me to ride off with it down before.
Pretty certain it's not the battery, having pushed it to Transit (the bike shop) they stuck a booster pack on it and cranked it with the throttle wide open for quite a while....
Time to pull the bodywork off again (only just changed the nose cone too)!
Cheers,
Tom

[Rubin215]

Well OP, did you get it going?

[darkyoung1000]

Not yet, today was a bit of a write off, but I have high hopes for the rest of the weekend.
There's a Corrado that needs fixing too....

[darkyoung1000]

Continuity on the sidestand switch checks out ok, and the kill switch is in order.
Next step will be tank and bodywork to check for a spark at the plugs.
Thanks all.

[darkyoung1000]

Just an update as I’ve only just managed to carry out more investigations (2018 was BUSY...!)

Had the tank and bodywork off and have checked the sparks at cylinders 1&2 by grounding them to the block. Sparks on both, so both sets of coils are working.
I bypassed the fuel pump using a gravity setup and the knowledge that I have a spark, but got the same results - it cranks and cranks, but doesn’t fire.

Next step is to check the compression, but I’m aware the CDI has previously been replaced and known to cause issues. I didn’t think I would get much of a spark if the CDI was dead though - any further thoughts or suggestions appreciated!

[Xtriple129]

I would have thought the fuel will have 'gone off' by now, modern fuel does rather quickly.

Drain and stick a couple of gallons of new in there to eliminate.

[CousinDupree]

Were the spark plugs wet?

Sounds like some crap got dislodged and blocked the carbs. Also how's the choke circuit?

Is there a sensor / pickup that could affect the ignition timing?

[darkyoung1000]

Just to close this thread, today, the ZZR ran again for the fist time in a couple of years.

I ended up checking the compression (all fine 125-130psi across all cylinders)
The CDI (spare from eBay - no difference to spark - i.e. there was one)
The coils (spares from...yup...there again) - no difference to spark
The sidestand switch continuity (again) - all fine

Put new plugs in....nope.
What the hell, new battery....

Ignition. Sweet inline 4 music.

Started by bypassing the fuel pump just in case, then checking it worked (it did), then doing everything we could to repeat the fault, but it wanted to keep running (albeit it was grumpy at having stood for 2 years).

My theory is that the old battery was too borked to fire it up, and by the time the cracking pack got on it, it was flooded.
Either that or the plugs weren't great, and the battery was on its last legs, and the combination sent me off on a wild goose chase.

Either way, with the help of a friend (none of this would have happened without them) the ZZR will be reassembled shortly and taken for an MOT....

[GadgeS3C]

Good result.

It's amazing how time flies and other stuff gets in the way.

[darkyoung1000]

Just a further update, as the last one was too good to be true. Went to start it again... and nothing. Well, what's changed since it was last running? Ummm.... nothing.
All the bodywork off again, and we're back to trying to work out what's wrong.
No spark at all, where before there was one. Coils check out and are getting power from the battery (the black wire) but aren't making a spark. The CDI has power and is receiving a pulse from the crank position sensor.
There was however no signal to the coils from the CDI though. On either coil. Both wires had continuity bergen the CDI and the coils though, so we have the culprit!

An intermittent electrical fault on the CDI that led to a lot of chasing unnecessary things. Here's hoping that this is the end of this issue (as new CDIs are £300)!