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News post published in response to a question on Fuel & Oils used, where to use and how much to use.
Many people have their own views on oils and mixes and I have tried to cover this in some detail, rather than reading what other people use and going with it, without understanding why. Here is the link:
www.lambrettajourney.co.uk/fuel-mixes-oils/
Along with the link above, these are my views along with additional information to aid you in deciding what oils to use and how much.
The images shown at the end of this News Post include:
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- Instructions for maintenance information
- The guidelines from the 1950’s manual.
- The guidelines from the 1957 Pitmans Book Of Lambretta
- The guidelines from the 1966 book The Official Lambretta Home Workshop Manual
General Information & Summary
Mk1 / Early LD’s use half a pint of oil.
MK II / MK III LD’s. The capacity of the gearbox was increased from half a pint to 1 and a quarter pints to the level plug. However, consider using only half a pint. (Comment from Cambridge Lambretta Workshop – a reputable source of knowledge and information – Many owners will notice that in the manuals 0.7 litres is advisable, or fill to the level plug, whilst this is fine you tend to find that to much pressure can build up within the crankcase and put pressure on the oil seals, causing premature failure due to the age of machines )
Things to know on oils:
Where I reference SAE30 for the Gearbox oil, mentioned is SAE40 SAE30 or SAE20, depending on the manual you use as a reference and the time of year (summer or winter). For the mention of this post (and what I use all year round) I will state SAE30 for the Gearbox oil
SAE20 comment – If considering SAE20 (in the winter), lower numbers represent thinner oils, and higher numbers are thicker oils. Using SAE20 in the winter should aid with the clutch plate not sticking on a cold morning, if your using your Lambretta LD on a frequent basis. You may use more oil though, as it’s thinner!
Summary: Remember, your LD is getting a little old. Check oil levels frequently.
Very important point to note for SAE30 oil:
SAE30 – (Gearbox. NB: This also fills the clutch). If buying SAE30, please do not get confused with lawnmower (4 stroke groundsman) SAE30 solutions and accidentally buy this instead of the SAE30 motor oil. If using SAE30, it should be the SAE30 Classic Motor Oil solution.
SAE30 Rock Oil (Engine motor oil) is hard to find in bulk. Link at the time of News Post printing is here for 5 litres – https://www.amazon.co.uk/Classic-Rock-Oil-30-Litre/dp/B01HD6UH60 . 2019 – It is typically £7 per litre.
Typically, half a pint if sufficient SAE30 used in a Lambretta LD
Other information
SAE140 – (Transmission, also know as Rear Gear Casing) Early Lambrettas did not have a filler plug located at the rear and seen in the diagram below as letter C. Instead, letter B (Removal of speedo and or cover) is required and used to fill the rear gear casing. A quarter of a pint should be OK for the rear gear casing.
Petrol / Gas / Fuels
For the fuel mix, a solution recommended is adding a 4% SAE 30 solution to your petrol. This is a recommended solution in the LD 1950’s manual.
For the fuel mix, some LD’s I am running are mixed with a 4% Rock Oil SAE 30 solution. This is a recommended solution in the LD 1950’s manual. (See attached image)
Some LD’s I am running are mixed with a 3% Rock Oil PP2 Semi Synthetic solution.
Starting your Lambretta having just purchased it for your consideration and tips:
Consider using a separate fuel feed (Bypass the tank and fuel tap) and feed the carburettor with a MOTORCYCLE Auxiliary Fuel Gas Spare Petrol/Fuel/Gas Tank Carb Balancing Tool Kit (Search online – approx £12) to start it up. Fuel taps can be a real pain sometimes and this will aid in any fault diagnostics work in this area. You can also see the fuel drop through to the carburettor, if your using a clear fuel line. Then when all works fine, start using the tank and fuel tap (Unless you run into problems and need to further fault diagnose this area).
If leaving the Lambretta to stand for a short while, remember to rock the tank to remix the fuel and oil.
Oils – What is recommend and what do I use?
Transmission (Or Rear Gear Casing)
The manuals state to use an SAE140 (As well as other oil options) I use the recommended SAE140, mentioned in the 1950’s manual and obtain it from Westway Lubricants Ltd via e-Bay.
Gearbox (includes clutch):
- The 1950’s manual states to use SAE40 for the Gearbox (As well as other oil options) .
- The 1957 Pitmans book of Lambretta state to use SAE30 in the summer and SAE20 (slightly thinner grade), for the winter.
- The 1966 book The Official Lambretta Home Workshop Manual state to use SAE30 in the summer and SAE20 (slightly thinner grade), for the winter.
My research has shown that SAE30 works best in temperatures of -5 to +35 degrees, while SAE40 works best in temperatures +10 to +45 degrees. Based on my use of my Lambrettas (and as I am mixing an 4% SAE30 oil with unleaded petrol for my fuel), I use an SAE30 oil solution for the Gearbox.
I buy my SAE30 oil from either (Rock Oil 5 lts) Amazon, or Westway Lubricants Ltd via e-Bay.
Click on the image to open a new window to print the JPG below
Image below – Comment from Cambridge Lambretta Workshop a reputable source of knowledge and information – ( Many owners will notice that in the manuals 0.7 litres is advisable, or fill to the level plug, whilst this is fine you tend to find that to much pressure can build up within the crankcase and put pressure on the oil seals, causing premature failure due to the age of machines )
