Ignition and battery problem kz750 ltd h2 1981

hi forum

please see new photos of my bike in the gallery.
I uploaded a before and after. I will upload more as when I complete it!

Problem

The bike won't start.

The bike has been completely rewired in 2009 and a boyer Branson ignition fitted.
A new battery was fitted. The bike turned over and a good spark was showing.
The bike work was stopped, some white van man shunted my car. I've just started again rebuilding.
Three days ago, no spark was showing? I connected my optimate optimizer and tried
Cranking it for a spark. The bike cranks very sluggishly, the lights, turns, gauges all lightup normally.
No spark?

As the ignition system is a Boyer Branson one, the bike has never started up fully.
The original motor 28k was replaced with a gem of a find, one with 6.5k.
Could the long stand in two winters, with some periodic battery maintenance
of killed the battery off?

If the battery has failed, what is the best battery I could buy please?
There are sealed 'hi torque' batteries or common batteries with distilled water etc.
I like the idea of a sealed unit, just like my VW Golf Tdi. No battery problems for 11 years.

What battery would the KZR's recommend please?


Many thanks

Angel - uk

Dear Kzr's

My kz750 ltd h2 1981 has had a Boyer branson
Ignition system fitted. Uses half the electric and better spark etc.

My bike will crank, very sluggishly, but will not spark.
The bike has been completely rebuilt and this my first attempt
To start it.

The Boyer Branson advises a fully charged battery.
Please see my other posting today.

Does the kz750 ltd h2 1981 have a ballast capacitor in it's harness?
I note that it was advised in the forum, that whenever upgraded
Coils etc are fitted, you need to remove the ballast capacitor.

I don't know whether my kz above, has one fitted.
Does anyone have a photo or any advice on this problem please?


Many thanks to all riders!

Regards

Angie - UK

Angel, I think the Item you are referring to is the Ballast resistor. this would be in the harness to drop the voltage across the factory points and condenser. If in doubt measure the voltage across the battery then at the positive coil terminal. If close to 2 volts lower than the resistor is most likely in place, which would then need to be removed from the circuit.
Batteries, well the AGM, Absorbed Glass Mat, is a sealed battery and will be more than a wet acid lead battery, but won't break the bank. If you don't want a wet cell then this AGM would be the next best. Yes you old battery would be needing to be chucked in the bin. Start with a new one.

Here's a pic of it, its under the tank on the left as you sit on the bike.

hi motor head

thank you for your reply!
the photo link had expired, what was the
photo of please?

good news, the new motobatt battery
made a considerable diff. to the cranking
speed. still no spark?
i've been doing some multimeter tests today.
the battery static was 12.8, cranking was 10.5.
the boyer ignition system kicks in at 12v.
each coil and 1& 4 or 2 & 4 plugs were tested against
the casing. it cranks, no sparks.
i isolated each coil, away from the other
linked coil and then repeated the other coil.
no spark?

the stator rotates, i then disconnected the battery and
also the stator wires. using a multimeter i checked
the resistance from the stator. each coil
should be 130-140 ohms. i only measure 68.4?
i think that one coil is faulty, maybe?

any advice greatly received, with a big thank you!

my bike is the kz750 ltd h2 1981 and didn't use points.
am i correct in saying that my bike never had
a ballast fitted. does anyone have a photo of a ballast please?

many thanks everyone! i want to hear the dinosaur
roar!

regards

Angel UK
((( hug )))

steelhorseangel wrote: ... no spark?...

With ignition switched ON, would measure voltage being actually received at the coil. Which ideally should match voltage measured between the battery terminals, but in reality may be sufficient if voltage being received at the coils is only very slightly less than voltage across the battery posts.

Battery voltage is usually supplied to the coils by a red or red/yellow wire (when the ignition switch is turned ON).

The other wire from the other coil primary terminal serves to ground and un-ground the coil primary winding. Often green to a coil for inside plugs, and black to the other coil for outside plugs.

When grounded, the coil charges. When un-grounded, the coil fires. (Presupposing a "good" coil.)

Good Fortune!