22 | February | 2022 | Motoguzzimackers' Moto Guzzi Diaries

I’d noticed an occasional petrol smell around the Cali. One day while cleaning it, I detected a slight sheen on the cable coming from the fuel-level indicator where it exits the tank near the fuel solenoid. I put up with it for a few weeks but it developed into a slight drip, so time to do something.

In addition, the timing sensor in front of the left-hand cylinder had been weeping for some time, a not uncommon occurrence. I searched the Moto Guzzi forums for information, of which there was plenty, and got stuck into it.

Firstly I had to drain the tank of 15L of petrol, then remove it from the bike. I pumped it out into a 20L container – man that’s heavy, which you don’t appreciate when it’s in the bike. Removing the tank is fairly straightforward; undo the retaining bolt under the seat, pull the tank back off its locating bungs, unplug the electrical cables to the solenoid and fuel-level indicator (it helps to prop up the tank with a block of wood to do this), undo the hose to the fuel solenoid, undo the hose to the pressure regulator at the front, lift the tank up and remove the overflow hose underneath, and carry said tank to somewhere soft where it won’t get scratched.

I’d never removed the fuel-level indicator before. It unscrewed easily and I extracted it.

After 20 years, there was a fair bit of grit on it and the union which brushed off easily. It didn’t look like rust. But now I was bit concerned about the fuel solenoid, too, so I undid and extracted that.

This was gritless! Beats me. The solenoid union nut is is designed to screw into the tank with a normal RH thread AND screw down the fitting at the same time with a LH thread to draw it up tight. I couldn’t get it to work properly until I’d removed the black cable-tie which held the electrical lead in place. A dab of grease on the tank thread and it screwed back in like a charm.

I eased the rubber boot away from the fuel-level sensor and squeezed some Threebond 1211 around the electrical wires exiting the base. The label says that it isn’t recommended for petrol, but they say that breaking the speed limit isn’t recommended, too, don’t they?! But it is OK with oil, and I’d bought it to fix the timing sensor leak. (The leak is also possible from the threaded join and some have found a slight split in the tank).

The timing sensor can leak where the sensor is screwed to the engine block, or out of the sensor itself. I extracted the sensor and found that the cable was grotty with oil and gunk, suggesting that oil was leaking out through the cable join. Cleaned it up with degreaser and then with methylated spirits. It has a spacer to ensure the correct positioning in order to read the crank rotations and an O-ring. Reinstalled these to the sensor then applied Threebond to the base-plate spacer, coated the area where the cable exited, and screwed it back onto the engine.

I poured some fuel into the tank and left it overnight. No leak. I smeared some rubber grease onto the locating bungs and eased the tank back on – the grease makes the job much easier – and reconnected cables and fuel hoses.

A week later and few hundred kays, all seem ship shape and Bristol fashion.