spark plug cap giving a reading of 11.5k, 1.5k over spec, not sure if that is a big deal.

It's old, just change it. The spec doesn't tell the whole story.

ok, so you have TCI, rare that they give trouble.


a few ideas to test:


check the ohms in the ign pickup (two wire connector coming form alternator cover, should be in the few hundred ohms range 500-700



TCI needs good voltage, try hooking bike with jumpers to a a big car battery


your coil is a 12v, disconnect the wires from harness, connect one spade to ground and flick over the other little spade connector with +12V from batt, should spark if ok


test and report

Thanks all, will have a go tomorrow.

pick up coil test
 

here is the result from the two pin connector

https://ibb.co/Rv9kDZc

i tested the connections of the 3 pin connector too, and they were all close to each other in value, here it is.

https://ibb.co/ZV4czbv

not able to get a car battery at the moment to test

Go with what Grant said and change it - NGK is my cap of choice. My rule of thumb with plug caps is any more than 5k is suspect. My old 70's Honda 400 won't start with 10k resistance in the line.

not sure how many ohms is that 0.22.... read my post, should be around 500-700, IF 0.22 means 220 ohms then something is wrong with the pickup.



the three pin is for charging, irrelevant to ignition.

Stop fooling this guy, all values are in spec, read manual before bad advices! My guess is fuel issue, hard to read the spark problem with so weak crank, fully charge battery and give it more time around on video, if no spark check leads and connections up to TCI, try another box. Remove carb, clean it and check fuel is leaving ok.

Surely dont know what you talking about, when he states its almost in spec you still say its no good over 5k?

Testing your spark like you are is not great. Leaning it against a dirty corroded engine is a crap earth for a plug.

Use a Jump lead from the spark to the neg battery or clean the cylinder with sandpaper and a file before testing it like you did. I couldn't see a spark from that video.

When you cranked over the motor with the powerstart, was the throttle open ?? It needs to be. It didn't sound like it was trying to start to me. Those coughs are probably from it igniting the powerstart just from the compression of the motor.

Test the spark again. Properly. With a clean earth point.
Replace your plug cap and HT lead (Or at least cut 10mm off each end of the HT lead and rescew)
Check your spark plug (That the electrode isn't shorting with the plug body) or replace it

Diagnose one system at a time or you will just get confused and frustrated.

Don't jump steps of diagnosis.

That's been my experience over many bikes and cars. New NGK caps are 5k resistance. Anything much over 10k (so a 5k cap and a 5k resistor plug together for example) is not helpful for cold starting.

My bike is yr 2000, and i experienced similar a yr or two ago. In my case i eventually traced the problem to a nearly broken wire at the CDi plug.

hello again

just stopped raining so could have another go

cleaned connections of the CDI, here's the before and after

https://ibb.co/XttfdW8

https://ibb.co/G7QGVhD

ran a jump lead to the negative on the battery, cleaned the battery connections.

and tried again with new cap new plug and that new ignition coil. here's the vid...


https://youtu.be/8OiHdT2JAKA

that's the battery at fully charged. it is 4 months old but was a cheap one

You definitely have NO SPARK. Or not a spark which is worth calling a spark.

Can you beg, borrow or steal another CDI ? Have you checked continuity, or better, voltage drop, from the CDI to the coil ?

I don't have an XT600 wiring diagram in front of me to look at but my guess is the capacitor in the CDI (Capacitor discharge ignition) is toast.

I think that's why you get the small spark then nothing. The CDI is not building up enough current.

If you're keeping the bike and it's an original CDI then you should change it anyway. Or at least carry a spare. So a CDI purchase won't be a bad idea.

You could also look a the ignition pickup. Or often called a pulse generator. It's what tells the CDI 'When' to discharge into the coil to create the spark.

Have you tested the AC output from the stator too. I'm testing my memory here but I think one of the phases charges the CDI.

Basically. You need to test your entire charging system. But swapping the CDI for a known good one is an easy first thing to check.

Ted

Measure the ignition coil voltage when cranking, seems like you have spark in the beginning and end. Measure wires to TCI unit, open TCI and check soldering points. Ignition coil have wire from TCI and engine stop switch.