PROX Connecting Rod Kit for HONDA XR 70 1997-2003

On HONDA XR 70 from 1997 to 2003, the PROX 03.1075 connecting rod kit fits in place of the original part. Between the piston and the crankshaft, the connecting rod takes every combustion and every climb through the revs. Replacing the rod, crank pin and bearing in time prevents engine failure.

Specifications

• Brand: PROX
• Manufacturer part number: 03.1075
• Engine: 4-stroke

When to replace it?

• Vertical play at the big end at top dead centre.
• Side play out of tolerance, signs of overheating (bluing).
• Vibration and dull noise from the bottom end.

During a bottom end rebuild, at the intervals in the service manual, and without delay as soon as play appears at the big end.

Fitting tips

1. Replacing a connecting rod means pressing the crankshaft apart and then realigning it: with a dial indicator, you check the run-out, i.e. the deviation in rotation measured at the end of the shaft, which must stay within a few hundredths of a millimetre at most. Leave this job to a properly equipped workshop if you don't have a press and a truing stand.
2. Replace the crankshaft bearings and oil seals at the same time.
3. Check the big-end side play after assembly.
4. Close up the engine with a complete engine gasket kit and tighten to the manufacturer's torque.
5. Check the gearbox bearings, then fill up with fresh oil and fit a new spark plug.

Why PROX?

ProX Racing Parts has been supplying engine and clutch parts to motocross riders since 1975, from its headquarters near Amsterdam. According to its catalogue, most of its parts are made in Japan, by manufacturers that also produce parts for the Japanese motorcycle makers.

Spare parts and items to plan

• Crankshaft bearings and seals : see the selection
• Complete engine gasket kit : MOOSE
• Gearbox bearings : see the selection
• 4-stroke engine oil : LIQUI MOLY 10W40 1 L · MOTUL 10W50
• Spark plug : see the selection

Frequently asked questions

Can I fit the connecting rod myself?
Yes, if you have a press and a crankshaft truing stand; otherwise, an engine workshop can do it for you.

What else should I plan for?
The crankshaft bearing and seal kit, the complete engine gasket kit, the gearbox bearings if required, engine oil and a spark plug.

Compatibility

Check the exact model and year of your bike in the list below before ordering.

Fits:
HONDA XR 70 2003
HONDA XR 70 2002
HONDA XR 70 2001
HONDA XR 70 2000
HONDA XR 70 1999
HONDA XR 70 1998
HONDA XR 70 1997