TL125 Ignition

[markcrossley]

I'm new to this site, so please be gentle.

I've just completed refurbishing a TL125 K1 imported from the US. I've rebuilt the motor with many new parts, and am happy with it mechanically. I have only a very faint occasional spark though, and the bike won't start.

There is only one generator winding which I have checked for continuity. Its resistance is about 3.5 ohms.

The HT coil is a new pattern one. The points and condenser are new, gapped and timed correctly. I've replaced the wiring, such as it is. Now I've run out of ideas. Do flywheels loose their magnetism with time? The flywheel is lined up with the key on the crank, so I'm assuming the mangets are phased correcly with the generator coil. I can't find a definitive figure for coil resistance, but 3R5 sound reasonable. It's sparking but only just visible if you look closely.

What does the panel think?

Mark

[max1956bikes]

polish the points must be perfectly clean.set at 12 thou.

[markcrossley]

Thanks Max,

Points brand new and .012"

Mark

[stork955]

Gday, what Max is saying is that new points come with a protective coating on them which needs to be cleaned off with solvent. Flywheels can lose their magnetism, a quick test is to see if a large screwdriver will stick and take "some" force to remove again. Check for continuity to ground at the coil, there should be none with the points open. You should have a low reading for when the points are shut -just the resistance of the source coil, around a couple of ohms as you have measured.

Cheers,

Stork

[tltel]

Hi mark

I would do as the others have said, but also check your earth connections to coil and condenser, that sounds more like the problem to me.

I have never known a TL flywheel or generator to fail.

good luck

TLTEL

[markcrossley]

Thanks chaps.

I'll clean the points and check the gap again, and check all the continuities. I've repainted the frame and made a new mounting bracket for the coil, but I didn't clean the paint from the mountings, so the earth might not be getting down.

Thanks again. I'll just have to defrost the shed door now...

Mark

[markcrossley]

So after letting my TL sulk for 6 months in the shed after your help, I had 10 minutes to spare at the weekend. I checked the points and reminded myself that I had actually set them to the high end of the range at .016". So I reset them at the recommended .012". A half hearted kick and bloody hell it started!

Five minutes later and I was riding round the garden like a big kid. Ebay project brought back to life.

Thanks for the info chaps.

So can you now help with suggestions for carb settings and any other twiddles for a newly rebuilt 124cc motor with a Sammy Miller exhaust and a brand new "Sheng Wey" carb that appears to be an absolutly exact copy of the very rotten original that came with the project.

I'm inspired again. Ta.

Mark