Ultrasonic cleaning of carburettors off a Yamaha FZR600 motorcycle.
Yamaha FZR 600 carburettor cleaning. The set of photos sent to us by a customer after before, during and after cleaning the carbs in an ultrasonic cleaner. The cleaning time was about 20 minutes using our carburettor cleaning fluid.
A bikers guide how to clean a carburettor with an ultrasonic cleaner. Which size and model to buy?
ultrasonic carburettor cleaning
This is a bikers guide to buying an ultrasonic cleaner for carburettors, explaining how to select the best model for you. A grain of sand in a carburettor can stop the most powerful of motorbike engines. In the World of carburettors, cleanliness is king.
Carburettor cleaning back in the day.
I have owned motorcycles for more years than I like to admit and have rebuilt a few engines including a vintage BSA Bantam (D2), Norton Commando 750 (fastback) and a Ducati (250 Desmo). Back in the day I would soak the carburettor in a bucket of Jizer type degreasing solution for an hour or two, rinse with water and finally blow it off with an air gun. Simple, but not really very effective carb cleaning.
Ultrasonic carb cleaning today.
Technology has advanced over the last few decades. As a result when it comes to cleaning a motorbike carburettor and engine components, the best practice is with an ultrasonic cleaner. Ultrasonic cleaners have a component called a transducer. This is the part that generates ultrasonic sound waves. The sound waves produce microscopic bubbles that very effectively dislodge dirt, grime and petrol residue from the intricate parts of a carburettor that would otherwise be difficult to get to.
Which size ultrasonic cleaner?
Price is always a factor and when deciding which ultrasonic cleaner to buy, but I have a mantra about the selection process – SIZE MATTERS. I can’t say that often or loud enough, so I will repeat it, SIZE MATTERS.
Measure your carb twice, purchase once.
Several customers purchase a machine after guessing or estimating their carb will fit into a particular size ultrasonic cleaner. As a result when delivered, they discover it’s too small and want to exchange it. That isn’t a problem, but it costs the customer money to return it and it’s a bit of faffing around. The golden rule: measure twice, purchase once.
Try and get it right first time by measuring the overall dimensions of your carburettor. However this isn’t always possible especially if the carbs are still bolted to the engine. In this situation it’s a “best guesstimate”. As you will be removing some of the carb parts such as float bowls, slides, jets etc the overall size of required tank might be smaller.
If you can afford it, select an ultrasonic carburettor cleaner a bit bigger than you estimate. Trying to shoehorn a large carb into a small tank results in the cleaning being less efficient. By placing the carb into a larger tank it allows the ultrasonic waves to travel more evenly and easily. As the saying goes, “what will hold more will hold less”.
submerged in the tank
after ultrasonic cleaning
dirt removed by the cleaner
Which functions do I need?
There are three versions for most sizes of ultrasonic cleaner. In summary, the more money you pay, the greater the control over the cleaning process.
The “manual” (dial adjustment) has limited control. The “digital” range gives you full control over all aspects of the cleaning operation and importantly, you have an LED display showing the temperature of the water (it helps stop the operator plunging their hand into hot water). In addition the degassing model can give a deeper clean.
At the heart of any ultrasonic cleaner is a transducer. This is the component that produces the ultrasonic cleaning waves. The more transducers fitted to an ultrasonic bath, the better the cleaning will be. If you want to clean a bank of 4 carburettors off a motorbike but don’t want to separate them, the 20 litre model will be the best size for you.
The analogue adjustment ultrasonic carburettor cleaner has a simple knob / dial to set the cleaning time (0-20 minutes) and another knob for the temperature adjustment (20 – 80 degrees C). There is no LED display.
These models have a push button to set the cleaning time (0-99 minutes) and temperature (0 – 80 degrees C) with an LED display. The cleaning can be stopped mid-cycle and the temperature shows both the target temperature and actual water in the tank. In a workplace environment and working with hot water, there might be a health and safety implication that requires the tank temperature to be visible to prevent scalding to an employee.
Digital adjustment with degassing
Degassing is an addition function which after a change a cleaning solution, quickly removes air from the liquid. It makes the cleaning process more effective and is especially useful when cleaning motorbike carburettors. With some degassing models the cleaning power can be reduced by 50%. This is so that delicate products can be cleaned gently. However, for ultrasonic carb cleaning, the lower power function isn’t needed.
The cleaning fluid
Picking the correct ultrasonic cleaning fluid is as important as the machine itself. The fluids we sell are specifically formulated to work well in an ultrasonic tank. Specifically, the carburettor cleaning fluid is made to work with alloys and alloy castings. It removes petrol residue and brightens dull castings. More information (and you can also purchase) on the fluid HERE.
Using the ultrasonic carb cleaner.
Using an motorbike carb cleaner requires no special knowledge or skill. All you need is water and a specific cleaning fluid to put into the tank. The cleaner is then plugged into a domestic power socket and the built-in heater raises the temperature of the water & cleaning solution mixture to around 60 degrees centigrade (maximum 80 degrees).
Honda CB350/4 carbs. Before and after cleaning.
Get it submerged.
After removing float bowls and jets, place your dismantled carb into the tank and turn on the ultrasonic control. Normally around 15-20 minutes is sufficient cleaning time. If the carb has not been used for many years you can leave the tank buzzing for up to 40 minutes. Leaving it in for longer will not damage it.
If parts of a carb will protrude above the water level. This isn’t a problem. Many customers simply turn the carburetor through 180 degrees and turn it on again.
After ultrasonic cleaning.
Remove the carburettor, rinse and leave it to dry. The carb will now be deep cleaned internally and externally the casting should look bright and clean. NOTE: Some alloy castings were dull when new. The ultrasonic cleaning process can’t make an old carb look better than the day it was new.
If you look through all the ultrasonic tanks we sell, the choice can be a little confusing. Below I have listed the most commonly purchased Ultrasonic Cleaners for cleaning motorbike carbs.
The 3 Ltr tanks are good for individual carburettors. A 6 or 9 litre tank will clean bigger individual carbs. If you need to clean a bank of 3 , 4 or 6 without splitting them, you’ll need a 20 Ltr size as a minimum.