Honda GX 160 Technical Regulations

Honda GX 160 Technical
function and the manner in which the engines are assembled. Please remember that save for the
changes specifically mentioned in these regulations the engines must be completely standard and
unmodified, and that all components will remain in place unless this document specifically states
that they are allowed to be removed. No specific coating procedures are allowed on any internal
or external surface of the engine. The fasteners on the engines may be drilled for the purposes
of lock wiring, as can drain and filling plugs. Replacement of external fasteners with non-Honda
fasteners is only permitted when the replacement fastener improves safety or when the standard
Honda fastener is not readily available. A thread recovery procedure is acceptable providing
that the system and replacement fixing used are of no different size or pitch to the original and
therefore offer no mechanical advantage over the original fixing, or alter the position of the original
fixing. Engine measurements must be taken with the engine in a "just-raced" condition, i.e. with no
removal of carbon residue or in any other way altered from the condition in which it was last used.
2. DEFINITIONS
2a. The standard, unmodified component
This means that the component has not had its substance altered in any way. It has had no material
removed from it or added to it (except as noted in these regulations). It will be of the same, original
material. Where appropriate, it should have the manufacturer's original manufacturing process
or machining marks on it. It is the component defined as being applicable to the particular engine
type. If it does not say you can do it, you cannot do it.
2b. Engine types
The original QHQ4 engine, to engine number 7664037, was known as the K engine. The QHQ4
engine from engine number 7664037 onwards was known as the E engine. The QHQ4 engine
with suffix T, from engine number 1000000 onwards was known as the T engine. That also
included all unified specification engines (GX160UT1 QHQ4 and QHG4). GX160UT2 QHQ4 and
GX160RT2-QHG4 engines (T2) All these engine types are eligible, with exceptions as notified in
the following document.
These regulations relate specifically to the T2 engine, references to all previous engine types have been
withdrawn. Previous engine types are subject to the regulations V11a of May 2016.
2c. Legality limit
In general terms, and where not clarified or qualified elsewhere in this document, the legal limit
for eligibility purposes shall be deemed to be the service limit as specified by Honda in the most
up-to-date Honda Service manual for the particular engine. (http://www.honda-engines-eu.com/
en/welcome.html)
Honda GX160 technical regulations
1. GENERAL
The scrutineer will pay special attention to ensure that the
finish of all components match those of the standard unit and
reserves the right to compare any part from competitors' engines
directly with a standard part as supplied by Honda (UK). Unless
competitors have gone out of their way to source alternative parts,
their engines should automatically comply with this rule. Furthermore,
competitors should note that the term "standard" refers not only to
the components used but also to the number used, their position and
shaded area denotes text amended from previous version
Version 13a
Regulations
31 March 2018 Page 1 of 10