Carb Cleaning (in situ lazy method)

You might consider Randakk’s GL1000 Carb Rebuild Video

Yamaha Carb Cleaner


Yamaha changed the formulation of this product…probably to make it more “green.” Yamaha now says to dilute this product with water instead of gasoline.

Also, the product is now intended for submersion cleaning only (with the carbs apart). The old stuff contained 2-Butoxyethanol and Xylene, the new stuff contains Glycol Ethers and Xylene.

My feeling is that the current formulation of this product is not nearly as useful and I do not recommend its use in the manner laid out in this Tech Tip. But, you may be able to find some of the old formulation on a dealer’s shelf.

The part number for the old and new formulation is the same. But, the new formulation is labelled “Carburetor Cleaner Dip.” The good stuff is simply labelled “Carburetor Cleaner.”

If the directions on the bottle say “dilute with water,” it’s not the good stuff you need for this procedure!

If you think your carbs need cleaning, try this first. Yamaha makes a product aptly called “Carburetor Cleaner”…comes in a large plastic bottle (not aerosol). I’ve had very good luck resurrecting dirty carbs WITHOUT disassembly using this product. When it works, this method saves time, effort and expense. Best of all, you don’t need new rubber components as you do when the carbs are taken apart. 

Yamaha Carb Cleaner

In my experience, this method is much more effective than running “in-fuel” cleaning products. “In-fuel” cleaners will only help on very mild carb problems. Chronic overuse of “in-fuel” cleaners or using them in excessive concentration can damage internal carb rubber components. This is especially true on GL1100s – the location of the 4 air cut-off valves and acclerator pump makes them very vulnerable. They are quite expensive to replace!

Worse, the excessive use of “in fuel” cleaners risks loosening up lots of crud in your fuel tank…another whole can of worms! The Yamaha product is harmless to carb components (and of course your fuel tank!) when used as directed.

Yamaha dealers sell tons of this stuff. If your dealer says he’s never heard of this product, consider finding another dealer then give him this part number:



Follow the directions carefully and PERFORM THIS WORK OUTDOORS DUE TO FUMES AND FIRE HAZARDS. The product is intended to be diluted with gasoline (1:3 ratio). First, drain all your carb bowls completely. Remove the fuel line to the carb plenum at the point where it leaves the fuel pump. Extend this line if necessary and attach a small funnel. Carefully and slowly pour the diluted cleaner mixture in through the funnel. It will take approximately 180cc to fill all 4 bowls. It may be necessary to gently tap the carb bowls with a plastic mallet to get the floats to release if they’re stuck in the closed position. If you’ve added 200cc of mixture and it seems that you could add more DON”T…you probably have a float stuck in the open position.

Place a fuel line from the fuel pump to a suitable catch container. Now, with the kill switch set to “OFF” operate the starter for 5 seconds with throttle wide open. This will draw some of the mixture into the carb circuits.

After 2 hours, drain the bowls and refill using fresh gasoline through the funnel. Reconnect your fuel line and go for a test ride. If you still have carb problems, the directions say you should repeat as above except leave the mixture in overnight. I’ve repeated this cycle up to 4 times before finally getting good results. This was on a bike that sat for 4 years with fuel in the bowls!

Generally, I will augment this process by removing the idle mixture screws and squirting aerosol carb cleaner through these circuits. I use a plastic attachment on the end of the red “straw” that permits a fairly effective “seal” so that I get pressure to help force the action. Also, I always make other external checks to make sure the choke shafts are free and that I have no sticking throttle slides.

Important: the Yamaha “Carburetor Cleaner” is intended for use in carbs only per the instructions on the bottle. Never add this product to the fuel in your fuel tank! It you do, you may regret it very much as it can loosen all manner of crud which will quickly clog your main fuel filter and float valve inlet screens.

If you use this product and determine that you still have carb issues which require disassembly, you’re still ahead as your carbs will require much less work to clean once they’re apart.

25 thoughts on “Carb Cleaning (in situ lazy method)

Add yours

  1. Anyone have a recommendation for an alternative to the old yamaha carb cleaner using this same method? It is now damn near impossible to find the original yamaha carb cleaner these days.

  2. mmm, I’m a bit confused by the information about the 2 formulations of carburetor cleaner. Your post about the new formula seems to be dated 8/12/16. I have part of a container bought in 2009, and an unopened container purchased probably a few years later. (Do you think there is a shelf life issue?) They are the same; black, oil style, plastic bottle with yellow printing– “YAMALUBE, CARBURETOR CLEANER DIP.” (I have not seen this same container on the web at all.) I thought they must be the new formula because it says to mix with water (although the person at the dealer said to use gasoline). However, among other things they contain 2-butoxyethanol (you say old formula) and tripropylene GLYCOL monomethyl ETHER (you say new formula).

    So, what have I got?

  3. Have you ever used the product simple green, alot of people on the cx500 fourms recommended it was just wondering about your take on it.

  4. You added a Note on August 8, 2007 but have yet to update this item. Is there a current (2013–nearly 2014) product that can/should be used in this Carb Cleaning (in situ lazy method)?

      1. What about using the B-12 in the float bowls only as you describe? I totally grok why you wouldn’t want to mix it in the tank.

  5. I have a pair of CX500 carbs that have the idle cutoff needle tang broken off down inside the body. Is there any fix for the removal? Are they completely necessary as some of the other model years had non-adjustable screws? I hate to junk these carbs as they are in pretty good shape considering this issue.

    1. Common problem when working with these carburetors is dealing with idle mixture screws that seem to be super glued into the carburetor bodies. They don’t always come out as easily as the GL1000 carb idle mixture screws do. There have been several occasions where I had to use a thin cutoff wheel and die grinder to cut a screwdriver slot into a broken idle mixture screw. Then a flat blade screwdriver usually gets the screw out. Carefully applied heat from a pin-point butane torch can help loosen the fuel residues that glue these mixture screws in place.

Leave a Reply

Your email address will not be published. Required fields are marked *

© Copyright 2024 Randakks Cycle Shakk

Top ↑