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Ignition Types

NO Urals approved for sale in the USA from the first ones in 1994
forward were approved for points ignition.
Type I - Models from 1994 up to about '96 or '97 had a 'Type I' - a
pot metal rotor on the camshaft with 2 steel slugs and a small sensor coil
mounted close to the rotor. A hand wound coil was also mounted under the
front cover. The 'brains' of the box were a bit bigger than a VHS cassette
and had big heat fins, mounted under the seat. The main problems with this
system was a relatively weak spark, and sometimes the timing curve diodes
would fail, but the diodes could be replaced with aftermarket ones and
usually gave good service after that.
Type II - Somewhere about 1997 or '98 the Type II appeared. All
of the electronics now fit inside a small C-shaped module that mounted
under the front engine cover, across from the magnetic rotor sensor. A
different coil was fitted that had a higher output. The components in the
module were 'potted' (encased in epoxy) to protect them against vibration,
like military boards. These modules had issues with heat buildup.
Type III - A few months after the Type II appeared, it was
replaced with the Type III (approximately mid-1998). Physically it looked
the same as the Type II, but the circuit board was modified to prevent
heat failure. Partway into the production span of the Type III, a high
output coil was mounted outside the front engine cover so it could stay
cool. This system was very reliable, although the heavy mass of the rotor
sometimes caused wear of the key. Also, a few cases of the steel slugs
coming loose from the pot metal rotor were noted.
Type IV - In 2002 with the adoption of the 750 engines the Type
IV was introduced. It featured more modern electronics. The massive pot
metal rotor was replaced by a lighter stamped steel unit with notches that
uses a Hall-effect sensor mounted in the module cover. The electronics
were incorporated on the front rotor cover. The coil was a newer design
high output unit that mounted under the front engine cover. A plastic
engine cover was used for heat dissipation. A built in diagnostic LED
simplified setting timing and gave indication of unit functionality. This
unit also had some heat related issues, partly caused by a method of
testing during assembly on one line - a surge was damaging a component on
this line during testing.
Type V - In 2004 the Type V appeared, which is basically a Type
IV split into 2 parts. The electronics were moved out into the airstream
for cooling. The LED is now visible without any disassembly. Extensive
testing in Europe revealed no problems, but there have been a few issues
with units in the US under very hot conditions and this is being checked.
Vance Blosser
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