Technical Tips

Welcome to the technical tips section. I`m hoping this section will grow into a comprehensive reference library for Laverda 500 enthusiasts. If you have a contribution to make which you think will be of use to fellow enthusiasts please send it to me and I`ll try to include it. I`m delighted to say that the first contribution is by Piet Hermann, a true expert in all things Laverda and somebody who has extensive hands-on technical experience with the marque.

 

Living with Laverda a 500

[Piet Hermann]

The Laverda 500 is a delightful machine, fairly light with good mannered handling and the best brakes on the market at the time. The engine, although it doesn’t seem very powerful in stock form, can hold its’ own against any contemporary road bike of the same capacity, it just needs a decent handful of revs!

Owning one is quite rewarding, so long as basic maintenance is looked after along with frequent oil changes.

One of the few glitches that might crop up is disappearing valve clearance. Valve seat material as used by the factory isn’t up to prolonged use with lead-free fuels; use of a lead-replacement concoction is strongly advised. While the ignition system was state-of-the-art at the bikes’ inception, it is a weak point today. Fine for track or racing duty, but today’s’ stop-and-go traffic will show its’ failings quickly. An inability to idle for very long without plugs fouling is the main symptoms. Precise carb settings are required, difficult with the units having 30-odd years of wear and tear in them. Reconditioning the carbs is an absolute must with new needle jets, needles and very often, slides being needed. Float valves tend to corrode/wear and jam, correct float heights are vital for safe high speed use.

The chassis is quite vice-free with only steering head bearings requiring replacement every now and then. The swingarm is located in rubber bushes that will be past their best by now, they can be replaced with needle bearings from the bigger brothers, the triples, basic dimensions are the same with only a different spacer tube and a grease nipple needed. The rest is all fairly standard equipment, although of very high quality.

Maintenance

Because the engine isn’t equipped with a proper oil filter, engine oil should be changed at 2000-2500km intervals. A good quality 20W-50 mineral oil is sufficient to keep the engine happy. The sump strainer should be removed and cleaned at every oil change.

Valve clearances should be inspected every 5000km at the latest, especially with stock valve seats. When adjusting, it is wise to err on the larger side, safety first! Cam chain tension should also be checked and corrected if need be. Cam chains should be renewed about every 35000km, the rubber coating of the chain tensioner blade tends to become brittle by then, replace as well.

The ignition system is maintenance free; adjustment is neither necessary nor possible! Spark plugs won’t last much longer than 15000km but are cheap and easy to source Champion RA6HC. If you cannot find any, drop into your local Harley dealer, they are stock fare on all Evolution Sportsters! For tweaked high compression engines and mainly high speed use, Champion RA4HC can be recommended. Plug fouling can be encountered at low city speeds, though. NGK alternatives would be 8s or 9s, 10s for high speed use.

Carbs should be stripped and checked annually, the float valve being the most vulnerable item. The spring-loaded plunger can wear away its’ stop and consequently lengthen the valve, lowering float height and fuel level in the bowl dramatically. Synchronising the carbs with vacuum gauges should also be performed annually.

Electrics are generally extremely reliable; connectors should be checked and cleaned after winter use, perhaps be sealed with a blob of Vaseline. Levers and cables require normal cleaning and lubrication, more in harsh environments.

Upgrades

The ignition system can be replaced with a modern system such as the excellent DMC II by Moto Witt. With carbs in good condition and a fat spark at low revs, the bike can idle almost indefinitely without stalling. A real feat considering the low flywheel mass of the engine!

Valve seats can of course be renewed with modern hardened seats that are suitable for modern fuels. While you’re at it, and if searching for a bit of added punch, the valves can be replaced with Atlas/Formula 500 items.

An Atlas/Formula 500 oil pump drops right in and gives additional peace of mind in keeping everything nice and slippery inside the engine.

Cam bearings can be either plain bushes or needle bearings. They were changed somewhere along the line during production, neither is better or worse than the other. The needles offer a greater safety margin in case the head is starved of oil, which hopefully will never be the case, but do transmit quite a racket through the cam cover.

For your favourite twisties, the Formula 500 gearbox comes in handy, offering longer and closer spaced 1 st, 2 nd and 3 rd gears.

Although not being a necessity, road engines can be seriously tweaked using Formula 500 parts such as pistons and cams. To gain full advantage of these, an open, free-flowing exhaust system is needed, not quite politically correct these days…..

Triple rear wheels can be machined to fit in the swingarm, offering the use of slightly wider modern rubber. Not only for added grip, but for tyre longevity, the patch placed on the road by a 120/80 is quite a bit larger than that of a 110/90. Current Bridgestone tyres are a popular choice, but everybody has their favourites when it comes to choosing tyres….

Fitting a #520 drive chain can unleash a little power by reducing unsprung and rotating weight and offering less resistance in the driveline. Atlas front sprockets are a direct replacement, the rear sprockets will need to be sourced or made to order. The stock rear sprockets can also be modified rather easily to fit. Piet

Swing arm bushes

[Bob Dixon]

The original rubber swing arm ‘void’ bushes work perfectly well, well enough to lap the TT circuit at 100mph anyway! Many machines are still fitted with their original bushes and will probably need replacing either with standard items or if you prefer, with a needle roller or bronze bush replacement. I don’t have any particular preference; I`ve fitted my Barcelona 600 with needle rollers due to the theoretical higher level of precision but I can’t honestly say that I found the standard items lacking in any way. I guess you pays yer money and makes your choice.

If you decide to change the bushes make sure you are well prepared because the old units can be very stubborn to remove. The outer bush casing is mild steel and can seize in the swing arm housing; the bushes sit in a recess machined into the swing arm and this means that there is very little purchase for a suitable drift to knock them out. For badly seized bushes often the only option is to burn the old bushes out ; be warned that this can be quite messy! Once the rubber has melted the inner sleeve will drop out and you will be left with a thin wall outer sleeve lodged in the swing arm. This needs to be collapsed to facilitate removal and the best way to do this if it won’t drift out is to cut it with an oxy –acetylene torch and collapse it with a suitable cold chisel. It might sound brutal but short of reaming or drilling it out there is no elegant solution so, if you haven’t got access to this equipment be prepared to remove the swing arm and give it to a pro to deal with, it will save a lot of grief in the home workshop. Bob