Sparking fault

[pmd31421]

Hi my Vtr1000 has lost the spark at the spark plug when cranking the engine over.
It sparks when I let the starter button go ....?
It's backfires and has fuel at the plug .
It ran fine last week when I put it on the bench to change the brake fluid.
Ideas ?
Pete

[sirch345]

Is the battery good do you know, does it turn over at a reasonable rate when trying to start the bike with the plugs in, not struggling

Have you removed and refitted anything thing since it was running good

Chris.

[pmd31421]

Hi , yeah turns over really well . Not 100% sure tho as it soon starts to slow down . Always started the bike before tho. Not taken anything off , I only changed brake and clutch fluids .
Pete

[sirch345]

In which case I would suggest charging the battery up fully on the bench with a motorcycle charger, and see if that helps it to start it,

Chris.

[macdee]

Is the battery good do you know, does it turn over at a reasonable rate when trying to start the bike with the plugs in, not struggling

Have you removed and refitted anything thing since it was running good

Chris.

As sirch has said i would start with the battery check the voltage
Starting your bike takes a lot of power from your battery so may be not enough left to run the ignition
what R/R is on the bike ,my reg died but before it give up the bike would not run properly popping and banging

[pmd31421]

Hi , thanks for advice . What I can't understand is why it sparks when I let off the starter button.
Pete

[954luca]

If the charging system is all ok, try replacing the plug, or swap it with the back one to see if still does it, my front plug lost its spark completely once, new plugs sorted it.

[alanfjones1411]

I would check battery,starter button,plugs,leads and coils.The starter button could be losing contact when pushed in and making contact on the release.

[sirch345]

Hi , thanks for advice . What I can't understand is why it sparks when I let off the starter button.
Pete

Possibly due to more power going to the ignition coils rather than the starter motor as soon as you leave the button go, with the momentum of the engine still turning a small amount after the the start button has been left go,

Chris.

[Pete.L]

Bang on Chris.
The load of powering the starter motor robs the coils of the ability to give a decent spark.
This is due to either a weak/poorly charged battery, poor electrical connections around the starter motor, solenoid or battery or even an old worn starter motor.
As has been suggested, start with the easy/ cheep stuff first. Give the battery a charge and clean the connections in the starter circuit


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[Cadbury64]

I've been resurrecting bike #3, an ST1100 that had been parked up for 8 years. Once I got the fuel system sorted (dead pump and blocked carbs) I found weak sparks in spite of a brand new battery, which made for really poor running at higher revs. One major culprit turned out to be corrosion in the connector that feeds power to/from the right hand switchblock. You should be able to check for voltage between the black/white terminal on the ignition module connector and ground, and expect to see normal battery voltage.

As stated above, try a charged or new battery first.