So I have nearly finished the resto of my 72 DT2 and I tried to fire her up tonight, but I have no spark,nada, nothing.

I would be very helpful for some diagnostic assistance as the bike ran fine before I stripped it and I have done virtually nothing to the engine,and I have a brand new plug.

One thing that concerns me is whether the engine itself should be earthed and if so where to? Having said this I have tried running an earth lead direct from the battery to an engine fixing and still nothing. For what it's worth, most of my other electrics (horn, headlight, flashers) work ok when I simulate a live feed from the stator.

Am I right in thinking that the coil is the first thing to check, and if so, how? Similarly how can I check that I am getting a live feed when I kick over the engine? It's a black wire going onto the cool, is it the black wire off the stator that I should be testing.

Unfortunately electricity is a bit of a black art to me so apologies for the dumb questions.

I'm not sure if this whole issue is related to my other post about an unexplained loose black wire - yamaha-enduros.com/index.php/forum/gener...2-wiring-help-please

Thanks

Here are a few things to keep in mind:

* Frame is the Common Ground[Earth] for the bike
* Engine is grounded to the bolted frame.
* The Battery Negative Cable[Black/Ground] is connected to the frame.
* The Main Wiring Harness has a rounded-edge, spaded, two-wire(Black)
terminal that connects to one of the mounting screws of the Coil.[Frame/Ground]

* The Main Switch, in position-1 - [off], grounds the coil ignition wire.

* Ground[Earth] wire is Black[at the Coil Mount].
* Stator Ignition wire is usually, also Black.

~

I would disconnect all of the Stator wires and
run a jumper wire from the Black Stator Wire, directly to
the Black Coil Ignition Wire, then crank and check for Spark.

I would also use an alligator clip jumper wire from the spark plug
electrode to the frame for a good Ground connection.


c.winterwoods

I don't know how points get dirty just sitting around the shop, but I've had it happen. Slide a piece of white business card between them and see what you get?

Thanks for the replies.

I haven't had much time to play but I did run a lead direct from the stator to the coil, bypassing the loom. Still nothing :(

Presumably if I put a tester on the lead from the engine and get some juice when I kick the bike over this would rule out stator problems and indicate the coil to be at fault?

"...and indicate the coil to be at fault?"


Yes, maybe on one end.

I would also check the other end:

Pull the flywheel and check the wire running
from the condenser to the contact points.

Sometimes the wire gets misrouted and it rubs
against the spinning flywheel flange and the
heat eventually melts the wire insulation,
creating a short - directly to ground.


c.winterwoods