You should perform a carb tune to ensure your bike runs as smoothly as possible, even if your carburetor is brand new, it still needs tuning. Carburetors are prone to cold start issues, and sometimes worsen fuel efficiency due to bad air-fuel mixtures.  Your engine, its condition, your location, and the weather all come into play and the carburetor needs to be adjusted properly.

If you are living in a colder region, you might have experienced difficulties starting your motorcycle. It is because there are no hot surfaces to vaporise the fuel being sprayed (lean mixture) from the carburetors. Resulting buildup of wet fuel droplets and ignition spark not being able to ignite it.

I bet it must be frustrating getting the cold engine running on cold days. On my old Road King, I’ve done a carb tune and it makes a difference straight away. I can hear a better idling sound and crisp and quick response! It runs like new again, with no more back firing and pulls a lot harder.

Let’s get into the points. In this article, I will be writing on some experience and questions that I have or I’ve learned on carburetors tuning:-

  1. The Function Of A Motorcycle Carburetor
  2. What Is A Carburetor Tune Up?
  3. How Much Does A Carb Tune Cost?
  4. Can You Clean A Carburetor Without Removing It?
  5. How Often Do You Need To Clean The Carbs?
  6. Do You Have To Synchronise Carbs After Cleaning?
  7. How Do I Sync My Motorcycle Carbs?

Mechanic repairs the carburetor of his motorcycle

Quick Recap: The Function Of A Motorcycle Carburetor

Motorcycle “carb” has only one job. Creating a combustible mix of fuel and air to generate power to “run” your bike. Over the years, a lot of modernised technology has been infused to enhance its capability; however, the basics of its mechanism has not changed.

Carburetors regulate the flow of air and draw gas to the engine via the intake valve. Generally, carburetors consist of a bowl, center bore, passages, vents, choke, idle speed adjustment, air-fuel adjustment and accelerator pump.

What Is A Carburetor Tune Up?

Well tuned carburetors can make your bike get the appropriate engine speed at idle while also keeping it running as smoothly. It is all about establishing proper fuel-air mixture. Excellent mixture, which also translates to greater fuel efficiency.

The way the carburetor supplies air and fuel are different at idle, and while running. A good tune means the engine should start and idle without stalling, and respond instantly. 

A mistune, on the other hand, will create more problems… Slightly richer fuel mixture is necessary to generate peak power, if the mixture is too rich, the ignition spark will not be able to ignite the fuel. If it is too lean, that is even worse, and might damage your engine permanently. 

Consistently running rich can damage the internal engines in a motorcycle. Unburnt fuel from a rich mixture can stick and get deposited into cylinder walls, pistons and exhaust valves. Over time, these deposits can cause wear and tear damages to engines and exhausts. 

READ MORE: Can Running Rich Damage Engines On Motorcycles?

How Much Does A Carb Tune Cost?

Carb tuning your bike at the dealer or the local shop usually costs around $100 and could cost you up to $200 or more. But, it is really not too difficult to do it yourself for around $30 bucks.

Do-It-Yourself $5 – $30
Carb Clean $80 – $100 per carb
Carb Clean & Sync $200 or more

It depends on the number of carbs that need to be cleaned, the costs of motorcycle carburetor cleaning can average about $100 per carb or upwards of $500 to $750 for all four. 

Some of the local shops do charge by hourly basis, and it could easily take 3-4 hours to complete. Averaging $90/hour, it can hurt your wallet pretty much, to be frank. Do check out this Carburetor Adjusting and Cleaning Kit that I bought on Amazon. Cheap and it works… They do work on any carb, I even use it on my lawn mower and chainsaw. 

Carburetor Adjustment Tool Kit I bought from Amazon

Can You Clean A Carburetor Without Removing It?

Yes, you can clean a carburetor without removing it. You need to first remove the airbox to get better access to the carburetor. Then, remove the bowls at the bottom of the carburetor.

To detach the bowl, there are usually a few screws around the bowl that will need to be taken off. Do expect some fuel to be leaking out while taking the bottom bowls off. It would be wise to get some used cloth or some kleenexes with you.

Note: Make sure you switch the fuel control valve (petcock) to the off position to avoid fuel running out.

Then, spray a generous amount of carburetor cleaner inside and let it sit for a few minutes. Spray a little more to ensure coverage. Then replace the bowls and start the motorcycle to assess how it runs.

This is what I usually do when I feel I need it, and in fact, I believe this is the quickest method to clean your motorcycle carburetors. A lot of issues associated with how a motorcycle is running is usually caused by dirty carburetors. Issues like this that frequently happen can make cleaning a daunting task if you have to remove it every time.

Do You Have To Synchronise Carbs After Cleaning?

You will need to re-synchronise your carbs after cleaning, repairing, or reassembling. Synchronised carburetors ensure smooth idle, greater power delivery, and quicker throttle response.

Go for a Carb Clean or Carb Sync if you are experiencing these:-

  • If you experience irregular or abnormal behavior on idle.
  • If you experience weird vibration you didn’t have before
  • If you notice your bike is draining your fuel faster than before.

After the adjustment, you will immediately notice changes immediately to the engine sound and throttle response. It only makes your ride become smoother or worse… 

It’s all about the right mixture of air and fuel, it may take you a few tries before getting it “on the spot”. 

WJ. Chai

WJ. Chai

Passionate rider who loves to discover new places. Since the pandemic, I can't go to places and I started to blog and share information that I learned. I'm not easily distracted, I just... OMG, do I hear a bike?

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