7: Service check.

By now I had driven 3000 km and it was time for a service check. I had, however, re-tourgued the cylinder heads, adjusted the valves and changed the oil after 1000 km because of the new cylinders and pistons. Whether it is necessary to change the oil at 1000 km is debatable, but why worry when oil is within easy economic reach.

Talking about oil I have made the following decision: I buy a well known brand, half synthetic, 10W40 and use the same oil every time. Whether you buy the oil in a supermarket or on a gas station (if you are able to locate the oil among candy, porn and whatever they have for sale in such places) doesnt matter. It needs exactly, 3 litres and the brand I buy comes in 4 litre jars. In the beginning I found that fine since that left something to refill if needed. It has turned out that mine doesnt use any oil – at least not something I can measure with the stick.

I have modified a 5 litre vinegar jug – cut a big hole in the side of it. It fits perfectly under my bike when I need to drain off the oil.

The oil filter on a Guzzi is placed in a difficult position. The oil sump has to come off. It is kept in place with 16 (or is it 18?) bolts – a lot, thats for sure. Some change the filter every third oil change - others every fifth and others again probably never. I plan to do it once a year. Use the UFI filters recommended by the factory. They are a bit more expensive than certain alternatives, but they work well and are get good ratings on pages where they test that sort of things. You can buy an intermediate ring for the oil pan which includes a pipe stub for an external oil filter. One day when I tire from removing the oil pan, I probably will make that modification.

I always keep an extra sump gasket, an oil filter and gaskets for valve covers on hand. Nice to have, if you suddenly feel like servicing your bike.

I also needed to adjust the valves, which I still dont do very well and I needed to adjust the ignition.

I hate breaker points. Having spent a couple of hours perfecting everything, I decided that it was never to happen again. I bought an electronic ignition – Dyna III – on the Internet. There are various electronic ignition systems you can use. Some are very advanced (and expensive) with computer controlled ignition timing depending on the number of rotations. Others – including the Dyna – use the original centrifugal advance system with weights and springs.

A week later my new ignition system arrived, and I took everything apart once more. The installation was easy enough. Off with the plate that keeps the points in place, install the printed circuit board, and a wheel containing a small magnet. I adjusted the distributor until it ignited exactly at the 8 degree mark on the fly wheel. I had, however, forgotten one thing. As it is a 4-stroke engine the fly wheel rotates twice for every spark in the plug. I had adjusted mine to the wrong stroke. The engine cannot start – and you can actually produce amazing flames from the carburettors. I have seen it with my own eyes.

After this small mistake the ignition systems has worked like a dream. It is hardly worth checking – it never moves. For me the price of the electronic ignition has been worth it.

If you plan to install an ignition of this kind then change the small springs by the swing blocks as well. They are pretty difficult to install but it is possible. Mine were somewhat slack after 25 years. The springs together with some swing blocks and the number of revs, decide the time of ignition. At low revs it is approx. 8 degrees from the top, at higher revs it is up to 34 degrees before the DTC. So these springs are not entirely unimportant. And since I replaced the breaker points you may spray the weights and springs with oil. My brother in law also ordered a Dyna for his Guzzi, and together we spent less than two hours installing, adjusting and putting the bike back together. Including a couple of beers. Its always easier the second time around. He has nothing but good to report about his ignition system as well.

Something else you have to do when you service your bike, is to synchronize the carburettors. There are several reasons for that. On of them is to make both sides perform equally as this makes the engine perform better. Another effect is that the vibrations in the handle bars are lessened considerably. When the carburettors are perfectly in sync you will experience almost no buzz in your fingers even after a long ride.

I had never tried this, so I studied everything I could find about the subject. In principle it is a question of making the two throttle valves open simultaneously. You can get far by feeling with a finger in the left carb, while you look at the right one and turn the throttle slowly. Adjust one of the cables until they open at exactly the same time. You can also hear when you turn off the gas whether both of the throttles hit the bottom at the same time. All this without having the engine started!

A more precise method is to buy an instrument designed for this purpose. There are various on the marked – some with mercury columns, others have columns with springs and some have indicators. Im sure you can buy electronic instruments as well, but that would be overkill. I dont fancy spreading mercury in the nature – but I decided to give myself an early birthday present. I bought a set with two indicators. Now it only takes a few minutes to adjust the throttles and my brother in law also appreciate the present I gave me.

Later it has turned out that the instrument handles Norton Commandoes, BMWs and Yamahas as well. So several people I know, have benefited from it.

Vacuum gauges .

You take a ride to get the engine up to normal working temperature. Between the carburettor and the cylinder head on the manifold, theres a 6 mm screw which you replace with a threaded pipe. From this there a rubber hose is connected to the meter. One at each side. Start the engine and let it idle. I have become convinced that the engine when idle, has to do 1000-1100 revs per minute – nothing less. The two idle screws are adjusted until both meters show the same value. The side showing the biggest value – and thus the biggest suction – is doing least. When you know that, it is a piece of cake to adjust the idle.

Next you need to adjust one of the twist-grip cables. In the manual for my kit is says - in German - that the indicators must follow each other when you slowly twist the throttle. I have tried to ignore this and adjust the cables so that the indicators show the same value at constant revolutions – say 3000. This doesnt work half as well as doing what the manual tell you to do. I thought it would result in less vibration, but it doesnt. Ask somebody wiser than me why that is so. But if in doubt you can always turn to the manual.

One thing vital to the road abilities, is the tire pressure. Check the air pressure! It takes less than 2 minutes and it makes a dramatic difference if the pressure is too low. It is OK to experiment – for instance I find that mine drives more precisely when the front wheel gets a bit more than recommended in the manual.