Tips For Any Repower Application
The demise of many familiar old engines is
bringing change to the Outdoor Power industry. The fact is, there are large
quantities of expensive equipment that will need new engines. With replacement
engines becoming unavailable, a whole new set of problems is developing.
Repowering is more than just buying an engine that will fit in the available
real estate and bolting it down.
Some of the factors that need to be addressed:
1. Electrical needs are different in the new generation engines. Ignition
systems are now solid state. Either the switches and sometimes the safety
switches need to be replaced AND rewired. This is a very time consuming and
costly approach, the alternative is the use of a conversion kit like the UK-1.
This solves the problem by mounting and connecting 4 wires.
2. Starter requirements may be different. Many of the new generation engines use
solenoid actuated starters. These starters require a significant amount of
current to engage. Most of the equipment not designed for these starters have
switches and wiring inadequate to meet their electrical needs. [The same problem
exists in much equipment built from the factory using engines with these
starters]. The UK-1 kit will quickly fix these problems permanently.
3. Cooling is the most important aspect of a repower. Air cooled engines
must have an unrestricted source of cooling air. In open air installations this
is normally not to difficult to deal with. Once an engine is installed under a
hood or in a piece of machinery, heat recirculation is a very present source of
trouble. Look carefully at the original engine set up. Are there any shields,
foam rubber baffles, etc.? Was the old engine ducted? If so great care must be
taken to address the cooling issues. When the cooling fan pulls warm air from
the exit side of the cylinders or muffler it is a problem. This often occurs
with heat rising under the hood or inside side panels and being pulled back to
the fan. Maybe the old installation was a horizontal twin and the heads spilled
air outside the hood and grill. A new V-twin may now dump all of this hot air
under the hood. Provisions will need to be made to address this issue. Pulling
in exhaust gasses creates the same problem. When heat re-circulation occurs
engine life can be VERY short.
4. Fuel lines need to be kept relatively cool. Allowing fuel lines to be exposed
to very high temperatures creates the perfect environment for Vapor Lock to
occur. Fuel lines will dry and crack quickly, bringing great risk from gasoline
leaks.
5. Fuel solenoids -- many new engines have
fuel solenoids. If the engine being replaced had battery ignition, using the
UK-1 for the conversion will solve this problem also. If the engine being
replaced was magneto the ignition switch may or may not need replaced.
6. Crankshaft and main bearings -- the engine must be selected for the proper
crankshaft dimensions. If the application has a heavy side load on the crank, it
may be desirable to select and engine with ball bearings mains. Appropriate
flywheel screens are important also. Does the application need a chopper screen
or will a regular one do?
7. Adapter plates may be needed for crankshafts alignment. See our selection.
8. Muffler and exhaust -- exhaust gases need to be routed away from the engine.
The routing needs to be done in such a manner that the heat does not get
recycled, the gases directed in the area away from the operator. Gases should
not get directed toward tires or belts that will be damaged by the heat.
External mufflers are no longer “state of the art” and need to be well shielded
because of liability issues. Mufflers that do not meet the engine manufacturers
back pressure specs when installed on a specific engine must not be used.
9. Fuel pumps -- the fuel pump needs to match the application. Some vacuum pulse
pumps cannot be used to lift the fuel more than 12 inches, some 24 inches. If
the fuel lifts are in the 24-inch area, a mechanical or electric pump should be
considered.
10. Summary: These comments are to provide awareness to some of the issues to be
addressed when one selects a spec or type engine to be used in a repower. The
many specs and types exist because of different needs in different applications.
We hope this sheds a little light on the subject.
