Help - R90S won't start

[Wanderer]

OK, a brief re-cap:

• August 2006 - gearbox failure, otherwise all OK
• Over last 18 months rear end strip to fix gearbox
• Nothing else touched - other than carbs
• Carbs have been properly refurbished by Mike Davies in Swansea
• Bike now back together

This evening's events:

• Went to start bike for first time
• Engine cranks over fine, but won't fire
• Checked spark plugs, slightly wet so petrol appears to be getting through
• Changed spark plugs, checked gaps, all OK
• Still won't start
• Check spark - plugs in HT leads resting on cylinder head
• NO SPARK, on either plug

And here I am. Slightly confused. How could I have lost the spark in both plugs? Could I be testing them incorrectly?

All advice/suggestions greatfully received.

Cheers

 

[(RIP) Proff]

OK, a brief re-cap:

• August 2006 - gearbox failure, otherwise all OK
• Over last 18 months rear end strip to fix gearbox
• Nothing else touched - other than carbs
• Carbs have been properly refurbished by Mike Davies in Swansea
• Bike now back together

This evening's events:

• Went to start bike for first time
• Engine cranks over fine, but won't fire
• Checked spark plugs, slightly wet so petrol appears to be getting through
• Changed spark plugs, checked gaps, all OK
• Still won't start
• Check spark - plugs in HT leads resting on cylinder head
• NO SPARK, on either plug

And here I am. Slightly confused. How could I have lost the spark in both plugs? Could I be testing them incorrectly?

All advice/suggestions greatfully received.

Cheers

Clean the points !!!
they'll have got a fur on them if They've been open all this time.
Also make sure the condenser is ok.
point gap is 15 though on peak of cam..
take plugs out to make it easy to get onto cam peak

 

[Wanderer]

Excellent, many thanks Proff. That's my weekend task then. Much appreciated

 

[cookie]

And here I am. Slightly confused. How could I have lost the spark in both plugs? Could I be testing them incorrectly?

All advice/suggestions greatfully received.

Cheers

have a shufty at the wiring diagram & look for any wire that's common to both ignition circuits, then check it's actually there and passing current.

maybe the power feed to the coils? i'll try and find a wiring diagram tomorrow.

 

[Wanderer]

Thanks Cookie, much appreciated. Second task for the weekend