Bandit 400 no spark and then some spark, but not enuff!!

[kjdoc]

I have read about every post that I can find about no sparking Bandits, but this is unique! I have recovered / repaired a basket-case 1991 Suzuki Bandit 400, and all systems and Ohms check out fine.

I cannot get a spark while cranking the starter and new plugs and battery. However, after cranking for a while (20-30 seconds) there is a small irregular spark, then it gets brighter and more regular and then shortly after the battery is too weak.

My question: What would cause no spark, to some spark to almost enough spark, but never start the engine??? After I recharge the battery, this happens all over again without results. It's like something is "warming up" each time!

I have tested the spark plugs grounded against the engine, then install them, but no start and an occasional backfire!! There is clean fuel supplied and the carbs are cleaned and working. All switches are good, bike in neutral, clutch in, stand up, I've tried every combination!

Thanks for your input...

[CestrianX]

The occasional backfire says it all I think.....timing. Is the static timing correct?

Is there a chance that someone else has had a go at it and failed? Maybe they have installed a new timing unit and not the gears for it, hence the occasional misfire.

[P.addy]

Got a spare set of coils?

[orac]

400 bandit suffer from coil leaking, give similar symptons as you have. they still indicate to be fine on normal checks, problem gets worse when it rains.

also check all the earths and power feeds to the coils, bandits like most over suzukis use a constant feed to the coils with a switched ground.

they also have habit of cooking caps in the ingnition controller. so try and lay tour hands ona spare one to check its not that
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Current rides - 2016 Triumph Street Triple Rx, 1994 Suzuki Bandit 400 VM, TGB 204 Classic 125cc
"with nothing left to lose, there is everything to gain. It's not the size of the dog in the fight, it's the size of the fight in the dog"

[temeluchus]

Similar experience with a pals Bandit 400, it turned out to be corrosion in one of the connector blocks under the seat.
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Some shite cruiser. Now with guns and FREEDOM!

[kjdoc]

Thanks for all your replies so far:

I do not have a spare set of coils…yet.

A timing unit, I have no idea of what that is… I will check the manual.

The ignition controller is brand new and functioning correctly… I think.

I will look for corrosion in the connector blocks, and add some extra earths…

[orac]

[kjdoc]

The Starter Relay is what I was referring to your suggestion of an ignition controller. May not be the same thing, but I did find one on e*Bay for only $19 USD.

If the ignition controller is something different, then there is prolly another piece I will need to search out with the "timing unit" that I am not aware of.

[orac]

Just having a re-read. The ignition timer maybe the same thing inwas talking about. It should be a black box under the pillion seat on that yeat machine, unless its been moved.

fyi, solenoid os not was talking about. However i am just thinking back, did have a similar issue that was caused by a bad connection from the crank position sensor. Follow the wires from the left hand casing (should come out near the starter motor), that is a small 2 pin connector that gave me issues once. Replaced with spades and heat shrinked together to keep the water out
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Current rides - 2016 Triumph Street Triple Rx, 1994 Suzuki Bandit 400 VM, TGB 204 Classic 125cc
"with nothing left to lose, there is everything to gain. It's not the size of the dog in the fight, it's the size of the fight in the dog"

[kjdoc]

[orac]

As in a couple of spade connectors. Cut the b lock. Lean off and relaxed it
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Current rides - 2016 Triumph Street Triple Rx, 1994 Suzuki Bandit 400 VM, TGB 204 Classic 125cc
"with nothing left to lose, there is everything to gain. It's not the size of the dog in the fight, it's the size of the fight in the dog"

[prawny1]

Will almost certainly be the ignition pulse coils playing up. my bro's gsx400 impulse used to play up merry hell, would sometimes not start then run cold but play up hot.

Changed the pulse coils and it ran like a top, his tested good too by the way.

Since you mention backfiring it is worth asking, are all your leads in the correct firing order?
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hellkat wrote:

Some people are only alive cos its against the law to kill them.

[kjdoc]

[orac]