Yamaha TRX850 Enthusiasts Forum

I have placed new pistons (CP, high compression). Engine back in the frame but no sparks on the new plugs... ;-(
Bobines are ok, bobine caps are ok, all fuses are ok... new battery, new plugs...and no: it's not the kill switch
And tomorrow I have a track day... Ignition dead?? How can I check that?

Thanks in advance guys

Is the rest of the electrical system working, do you get the neutral light on?

I'f you've had the whole engine out and it was working before, I'd check you've got your're earth points back correctly and they're not corroded etc. If the bike did work but now doesn't its unlikely that something has failed whilst you were fettling the engine. Far more likely that something isn't were it should be, have a really good go over the bike and check for any stray leads, then its the painful task of checking all the connectors. Hope it helps.

There is an earth strap up near the coil mount plus one on the top sump cover bolt.
If you have power but no spark,
Look for issues with your cut out switches including at the clutch lever and the side stand switch.
If you have used a different 2 or 4 pole key ignition. Red and black 15 amp cables are your power.
The 2 smaller striped cables also impact on your cut out switch/ ECU.
It was a couple of years ago when I did mine and can't remember if the 2 striped cables are isolated from each other or joined to make the curcuit. Joined together or isolated which ever way, they earth the ECU through the cut out switch curcuit.

I think that I'm going to make a new wiring loom
The last year I removed the dashboard, lights, etc.... I just have a temp. gauge and a tacho...and eliminated the rest. Maybe there is something wrong in what left of the electric system.

The 2 smaller striped cables also impact on your cut out switch/ ECU.

That's also a option...

Thanks for the advice guys

The 2 striped wire and black and red 15 amp wires I referred to are connected to to your ignition barrel. If you havev't changed this I'd look at your cut out switches and neutral wire from the gearbox.
The single bullet connector near your rear shock reservoir

Found the problem...

The single bullet connector

...stupid that I missed this one, it took me a trackday.