How to install the oil pump and oil pump chain – Honda CX500, GL500, CX650, GL650

Here’s how to install or reinstall the oil pump and drive chain on a Honda CX400, CX500, CX650, GL400, GL500, GL650 or GL700 motorcycle.

This assumes you’ve cleaned the filter screen and/or assessed the internals, have replaced the O-rings and are reinstalling the pump.

Make sure the dowel pin is in place in the lower of the three bolts – part number 94301-08140, 8x14mm for all models:

Slide the oil pump assembly on – the dowel should seat neatly into the lower bolt recess:

Loop the oil pump chain – part number 15140-415-003, all models (eBay part number, eBay (general)) – over the sprocket on the crankshaft:

Place the oil pump sprocket into the chain, rotating the oil pump mount to align with the hole:

This chain was within spec when the oil pump was adjusted – though it’s currently looking rather loose, so don’t panic if yours looks similar:

Add the washer (90486-028-000, eBay US, eBay UK, eBay AU) and bolt (92000-06008, 92000060080A or 92101-060080A (eBay US, eBay UK, eBay AU), 6x8mm) to the oil pump sprocket and torque to 10Nm – you may have to hold the crankshaft while you are torquing it as it may well move the crank! Once that’s done, adjust the oil pump chain slack.

There’s no harm in attaching the sprocket to the oil pump before putting it into the engine as per the factory manual – I find the above an easier order of things for my stiff fingers in terms of fiddling with the chain so that’s how I approach it.

If you are doing this as part of a triple or quadruple bypass procedure, click here to go back to the main bypass page.