Primary Chain (Hy-Vo) gets loose and taps off the inside of the casing

Renew the primary chain or create a primary chain tensioner to take up slack

This is what Warren had to say on the subject:

"Fuel tanks are around 17-18 litres on standard bikes. Later 750s and all 850s in Europe had 24 litre tanks that fit straight on. Buy one and change it out. Make sure you get the fuel taps as they are slightly different, but only one will fit if needed."

This is true, and if you are a practical crossing-the-continent kind of guy then it's good advice. But for some people (me included) the original standard tank is a thing of beauty and stopping every 120 miles or so for petrol is a small price to pay.

Vacuum Fuel taps leak Can leak and combined with carb needle valves failing can flood fuel into the cylinders

Change taps for manual taps, or modify existing vac taps to manual. Always turn off fuel when you leave the bike.

Early models had "sealed beam" headlights. This type of headlight has no separate bulb; the main and dipped filaments are moulded into the reflector and lens assembly and the whole thing is a single unit. There are 3 issues with these things nowadays:

• The whole headlight unit requires replacement if one filament blows
• They are not so easy to buy, compared with replacement bulbs
• The light output is very weak compared to a modern halogen bulb

Later models (1978-79) have a halogen headlight with a standard H4 type bulb fitted. You could buy a used lens and surround, or alternatively there are halogen conversion kits available from companies such as Yambits.

Was a big problem on early XS750s but seemed to be cured by the release of XS850. If it only slips occasionally, then a simple shimming trick can be done without splitting the engine cases.

We have compiled a list of useful contacts and tips on the suppliers page.