Carb Cleaning (in situ lazy method)

You might consider Randakk’s GL1000 Carb Rebuild Video

Yamaha Carb Cleaner

Update:

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

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:

#ACC-CARB-LE-QT or #ACC-CARBC-LE-NR

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.