As I said last time, what with one thing and another there’s been no more progress with Rhino. However, I’m off to the Moto Guzzi Club GB V-Twin Rally at Fordingbridge in Hampshire on Friday on my other bike, the 850 engined S3. The beast was more than due for a service and I thought I should do this first although there’s always the worry that something will get busted just before I need to set off!
Although servicing an old Guzzi seems straightforward enough to me I’ve decided to include this post as I realise that not everyone has been brought up on old engines. I’ve also come across people asking how to get the fork oil in more than once. I’ll also show how I adjust the valve clearances which is something I haven’t done so far.
Old oil is not good for you and, sadly for someone who likes old vehicles, I react badly to the stuff so I wear mechanics gloves if there’s a chance I’ll get any on me. They’re the knitted type with rubber palms and fingers.
First thing to do was to drain engine, gearbox and rear drive. I didn’t bother to run everything till it was hot enough to scold me. I just left it draining overnight. The funnel directs the gear oil to the tray.
Engine oil and filter change.
Next the sump has to come off to change the filter. I don’t do the filter at every oil change. It’s just not necessary. The bike does enough miles to warrant an oil change at least once a year and the filter gets done about every third change. The sump is held on by 18 allen bolts. There are 14 around the perimeter of the sump and 4 more amongst the fins underneath. These ones are often missed and tales of sumps being hit with mallets (and worse), before the discovery is made, are common. With the sump on the bench removal of the filter is easy enough. I generally give it a bit of a wipe then grip it with my rubber-gloved hand and it’ll come off. I have got a chain wrench but have never needed it. I then took the opportunity to clean out the sump and removed the wire gauze and cleaned that as well. On Rhino this gauze is all there is to filter the oil. I don’t like the idea of paraffin in my engine so I just wiped the sump out with loads of old rag but the gauze was cleaned in petrol then dried. There were no nasties in the oil. It was just black. No metal bits and nothing stuck to the magnetic sump plug either.
I write the date on the new filter even though I can’t see it! It’s a habit gained from servicing old cars. The filter that came out was marked 21/05/10 so had been in there longer than I had intended. Tightening the filter with the grippy glove is plenty tight enough. The sump gasket was still good. I like to use thick gaskets and give them a coating of grease so they come off without a fight. A little more grease was rubbed on and the sump refitted.
The engine oil was then added using an old washing up liquid bottle. The spout is just the right size to clamp on a piece of fuel hose which makes the job less messy.
I use 20W50 oil as per the original spec. The S3 engine is supposed to take 3.5 litres of oil and this time I got the whole amount in without over-filling. 3 plus a bit litres brought the level to maximum initially but I knew the filter etc would be empty so I removed the plug leads and spun the engine over on the starter till the oil light went out then waited a bit. then I topped it up again. You use the dipstick to check the oil level by just starting it in the threads not by screwing it right in.
750cc of gear oil was added to the ‘box plus a titchy bit. This titchy bit seems to be needed to get the oil to start coming out of the ‘box’s level plug and then is lost. I suppose I could just add the 750cc and be done with it. The oil originally specified for the ‘box and rear drive was Hypoy SAE 90 which you are unlikely to find these days. I use an EP 80W90 which is what Guzzi now recommend.
Rear drive box.
When it comes to the rear drive box. I mix up 230cc of the gear oil with 20cc of Moly additive. Again this was the original spec and I see no reason to change. Some people say that the modern gear oils make the additive redundant but I won’t take the chance. I’ve had a pinion gear fail several years ago with a vague recollection that I left the additive out because I couldn’t find any at the time. When filling, I just add the measured amount. I don’t use the level plug on the drive box because it won’t allow you to get enough oil in. The reason, as I understand it, is that the level plug is only accurate if you have the swing arm itself absolutely level. When you have the bike on its centre stand and the shocks are at full drop the level hole is too low.
Fork oil change.
Then I turned my attention to the front fork oil. Unusually, Automatic Transmission Fluid (ATF) is specified for old Guzzi front forks. They don’t need motorcycle fork oil as the dampers are self contained. The oil is just used to lubricate the innards. First the old oil has to come out. Drain plugs are situated at the rear of the fork legs.
If you just undo these likely nothing will come out as you need to remove the fork top plugs as well. Only do this one side at a time or the forks will collapse when both springs and dampers pop out of the top of the fork legs! On the S3 and the V7Sport start by removing the instrument console from the tops of the forks. Then the special bolts these mount on. Using a 32mm six-sided socket (12 point socket will slip) remove the fork top plug. This turns the damper inside the fork leg. This should be OK but, if you’re unlucky the assembly will unscrew from the bolt securing the bottom end to the fork slider. It’s not really much of a problem as you can probably screw it back on from the top but will then have to take the wheel out to tighten it up from below. If you are really, really unlucky the damper will come adrift from its extension that has the spring mounted on it and the whole lot will come apart. It shouldn’t as there’s a lock-nut but it does happen sometimes. This unfortunate situation means stripping and rebuilding the fork leg and is one reason not to do this the day before setting off on a trip. All went well for me so I must have done something right in a previous life. The oil that came out was still bright red and would probably have been ok but you don’t know this till you drain it.
Now to get the new oil in. With the drain plug back in complete with a new crush washer, ATF can be squirted in with a syringe down beside the top of the damper unit like this.
On the S3 each fork leg gets 70cc of ATF. I’ve no idea why as they look to be the same as those on the V7Sport which only get 50cc. Now the top plug can be replaced and the job repeated on the other side.
I replaced the special bolts that secure the top of the damper and mount the instruments with the stainless ones made for me by “Bunny” when I needed a set for Rhino. The originals were bent.
Valve adjustment (tappets).
The valve clearances should be checked regularly and adjusted as necessary with the engine cold. Old Guzzi valve gear should be rattly. If it’s not the gaps are closed up and that way lays trouble! To get at the adjusters the rocker covers have to come off which is pretty easy as it’s just a matter of removing the allen screws and lifting the box off, especially if the gasket was greased last time so it’s not stuck. I always have a rag handy as there is usually a little oil spillage. Then take the bung from the hole in the bellhousing. Take the spark plugs out, put the bike in gear and turn the back wheel in the direction for forward travel watching for the “D” mark to come in to view. This is the Top Dead Centre setting for the right hand cylinder. Take a look at the rockers and see if they are slightly loose meaning that both valves are closed. If they are tight and a valve is open keep turning the back wheel till the “D” comes round again. Everything should now be free.
Get the feeler gauges and stack them so they make up 0.22mm which is the clearance we want. They should be a sliding fit between the face of the rocker and the valve stem. I found that the exhaust valve was still spot on but the inlet was a bit wide so I slackened off the adjuster lock nut and turned the adjuster in slightly till I got the sliding fit I needed. You hold the adjuster in place and tighten up the locknut. Then you check the gap again. For some reason it took me three goes to get it right this time.
I revived the gasket with some more grease then put the rocker box back on. be careful when tightening up the allen bolts. I use a standard length key for all but the top two so I can’t get carried away and strip the threads in the cylinder head. I have to use a 1/4 in socket drive to get to the top two screws but I’m very careful. When I got the bike (in bits) I had to helicoil one hole in each head due to this type of damage.
Next I transferred my attention to the other side. Same procedure but turn the back wheel till the “S” comes into view in the hole. This is the setting for the left hand cylinder. “Sinistra, destra, sinistra, destra” I seem to remember the Roman soldiers chanting as they marched along in an Asterix the Gaul book I read many, many years ago! Funny what you remember. Back at the job in hand I found these valves didn’t need adjusting. ‘Tis a good sign. If the clearances were closing up it might suggest that the valve seats were wearing.
Check and adjust spark plugs.
I know, nobody bothers anymore and plugs are routinely thrown away and replaced but, old habits die hard and I still clean and regap plugs. This time they were a nice colour indicating good combustion but even I could see they had reached the end of their life. So the new plugs I carry as spares were gapped to 0.6mm and fitted. The old ones were regapped as well ‘cos they’ll be the spares now.
I use NGK BP6ES plugs without the nipple thing on the top. The caps I use (also NGK) grip the exposed thread. I changed to this arrangement about a year after I put Rhino back on the road the last time and have carried it over to this bike. More than once, I’d be riding along when the bike would go onto one cylinder and the left hand plug lead would have come off and be banging me on the leg. Somehow the nipple thing would slowly unscrew and come off the plug. You’re then faced with having to get the plug out of the hot engine at the side of the road because you need it to recover the part still (thankfully) being firmly gripped by the plug cap so you can put it all back together again.
Check and adjust the contact breakers.
I really should have done this but didn’t. The fuel tank is full and I need to at least raise this to do the points. Usually I take it off but full it’s heavy. I’ve had no sign of any ignition related problems and it was only about 2000 miles ago when they were last looked at. They don’t have to work very hard and, in all my Guzzi riding years, they have not caused any problems… yet, which is why I’ve stuck with them and not changed to some sort of electronic ignition.
Basically I’ve run out of time now so I checked for slackness in bearings (steering head, wheel and swing arm) and loose nuts/bolts. I had a look for any signs of frayed cables and would have lubricated them given more time. I checked the run of the wiring for any chafe points and all was OK. I had a wire rub through a couple of years back which caused a small fire and led to a ride on a recovery truck. The brakes are fine.
Then a quick run up the road to make sure it all still works and I noticed that the bulb in the speedo has called it a day. I’d not noticed this before as I rarely ride at night. It can wait.