20,000 Miles in a Lawn Mower by David Marsh
Hello from the best place in New Zealand -
My Isetta has covered some 20K miles since I brought it here -
Nelson area is quite small (40,000 residents) but this rises in the summer with many visitors. The car is always the centre of attraction when it’s parked (with the usual questions) and on the road it attracts lots of waves and smiles. To help combat “answer fatigue” I have had a plaque made up with the answers to the most common questions I get asked (and the answers) which I display together with an information board about the car when it’s parked.
The Bubble is kept in a car port which I built some years ago attached to our garage. I do nearly all the work on it myself – except for specialist engineering of parts which I get made locally. This is because Nelson is a sea port with a thriving ship building and repairs industry so I can find most of those long lost skills such as electrical coil rewinding locally.
So what has driving it for so many miles taught me?
Firstly Tyres – the Kumo tyres on the car have done well and I managed to get a new set via the local tyre depot so I am fitted up for a few more years yet. I did have one tyre where the sidewall failed and bulged a bit. By a process of trial and error I have decided the best tyre pressure is 24psi in the front and 28psi in the back wheel. I rotate the front wheels over (left to right) every 1000 miles to even out the wear
Oil changes are done every 5-
The Dynastart needs to be stripped and cleaned once a year otherwise dust from the brushes builds up and starting gets tricky(er).
Contacts are set at a very tight 15 thousands of an inch – it’s better to go a little smaller (say 13 if you can). Spark plug again I set at a tight 25thou mostly about 22thou. I find the NGK B5HS spark plug is the best.
Gearbox and final drive chain levels are checked every 500 miles – mine seems to EAT gearbox oil – it’s actually a small leak but it’s a good leak as it drips onto the rear spring! I overfill the rear chain drive i.e make sure its full using the level plug then add some more just in case.
The horn system has given trouble four times – usually the wire inside breaking off the ring – I have now given up and put in a standalone horn button instead.
I have had a small problem with WOF’s in respect of the front brake drums slightly rubbing on the brake back plate. This is mostly due to either rust or dust on the drum or when I take the wheels off during servicing and not tightening them up gradually to ensure they are 100% square on the drums.
The 5 grease nipples and the 2 pots in the front (using a mix of 80 Hypo and grease – they still leak a lot though) are done every 1000 miles. I take off the brake drums every 1000 miles and clean them out and check the linings and the slave cylinders.
Hand brake adjustment is once a year to keep it at 5 notches to being locked on.
Clutch Adjustment twice a year – just the cable adjuster about a half a turn or perhaps three quarters.
I have a calcium battery fitted to the car – I also have fitted a voltmeter – the voltage regulator is set to max out at 14.5 volts. Even then I still put the car on a tickle charger over night as starting on the Dyastart (especially in the winter) is not this cars strong point.
I had quite a few problems initially with the clutch and throttle cables breaking just behind the lug. This turned out to be that the lug at the end of the cables which connects to the clevis pins in the pedal mechanism was too large and not rotating on the clevis pin. I also got some brake pipe rubber concertina gaiters and fitted them to ensure the cable ends were enclosed. I fill these gaiters once a year with oil and grease.
Check the track rod bolts are tight every 1000 miles.
Light bulbs can be problem as the headlight bulbs available here are made in China and in the last 2 replacements I bought I found the filament was not installed properly so the light beam was all over the place.
It’s important to ensure the fuel tank is full or totally empty if you leave the car unused for a time. This is because the fuel seems to quickly absorb water which gives you really funny problems when or if it starts.
o If the fuel gets contaminated then I pull off the rubber hose which connect the tank to the carb and decant about half a pint of fuel from the tank and also ensures the carb has drained itself then reinstate the pipe.
o If you don’t do that you can get the following funny symptoms. – The car is hard to start and then won’t rev up -
o The engine will run as long as the car is on the flat but the second you go up or down hill it will stop and won’t restart again.
The car has broken down on me twice – both due to the contacts closing up.
The only other problem I had was with the rear brake shoes which suddenly had oil on them. This turned out to be due to two things. First the back brake plate had not been fitted with a gasket between the chaincase (someone previously had just used clear silicon!!). Second the brake plate had been positioned wrongly – i.e. the grove in the brake plate must point down so any oil from the chaincase drips onto the floor and not into the brake drums.
Because it’s classed as a motorcycle I can park it in a motorcycle parking bay all day for nothing.
So what’s happening next I hear you ask? Well after 5 plus years the cars is due for some serious attention over the winter. I plan to take the body off the car – that makes it a lot easier to do stuff. I will do all the usual checks and take off the cables and properly lubricate them. I also plan to swop the engine over with a spare one that I have rebuilt over the last couple of years. The existing one will be stripped and rebuilt. I will change the clutch plate and also the drive shaft Jurid couplings. I will also change the track rod ends. I may also get the front door and front mudguards re-