HISTORY OF IGNITION TYPES - Ural
THIS ARTICLE WAS WRITTEN BY VANCE BLOSSER AND PUBLISHED HERE WITH HIS PERMISSION.
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.
This Page was last updated: Monday, April 21, 2008 at 1:07:32 AM
This page was originally posted: 9/13/04; 7:14:50 AM.
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