There are a couple of approaches here. The basic or minimum-diassasembly method is recommended in the Clymer manual, which says that if you need to separate the carbs you should take them to the dealer. OTOH a complete rebuild, with a thorough cleaning by immersion in carburetor cleaner and such things as proper lubrication of the felt throttle shaft lubrication rings and replacement of fuel joint and air joint O-rings, requires complete disassembly. The Honda manual provides instructions. However, basic inspection and cleaning can be done without separating the carbs. If you do take them apart, eyeball the initial balance by lining up the throttle plates with the bypass holes before reinstalling them.
Do you need 4 $30 rebuild kits? Unless you have to replace parts, this also is your call. Many list members have re-used parts like float valves and bowl gaskets successfully.
According to a Honda America employee:
"Don't put silicone anywhere on a carburetor. A very light coating of Gaskacinch (the Japanese equivalent of what is used at the factory) works good. If the gasket appears limp, or if injudicious use of carb cleaner has made it swell and become difficult to glue down, drop it in a container of hot soapy water for several minutes to normalize it. Then lightly coat it with Gaskacinch, let dry, and very lightly coat the bowl groove, and let dry, and put them together."
Note that the Honda manual says to remove the starter jet. The starter jet is removable only on some Sabres & Magnas; on others it is pressed in. There appears to be no particular pattern to this. If it doesn't have a screwdriver slot or hex on it, take the hint. Otherwise just follow either manual.
If you have a vernier caliper of the kind where the sliding part sticks out of the butt end when you open it up, the sticking out part makes a pretty decent float level gauge. Northern Tool has a 6" ruler that works very well as a float gauge: [http://www.northerntool.com/shop/tools/product_200314332_200314332]
Make sure carb cleaner or WD-40 blown into all the appropriate orifices comes out the holes in the carburetor throat, and don't forget the air jet orifice upstream from the butterfly. (Be careful not to get carb cleaner in your eyes.)
There is something of a controversy regarding use of wire to clean jets, and technical columns in magazines don't agree on this, either. OTOH there are times when there's something in there so stubborn that only a good stiff wire will get it out. The key thing is to not damage the orifices, so it would be best to use a carb cleaning tool, which has smoothly ridged wires of various sizes. They are available by MO from various sources, and similar if not identical tools are sold by welding supply stores for cleaning the tips of oxyacetylene torches. Note: Copper wire is softer than brass so you don't have to worry about enlarging any jet holes. A strand of copper pulled from multistranded automotive wiring works well.
One thing you must do: keep the parts from the different carbs separate; some of them are not the same. Large numbered zip lock freezer bags work well for this. One list member recommends replacing "all those worthless phillips head screws" with corrosion proof allen head screws--on the bowls, top plates, and especially the airbox-to-carb screws.
Here is a picture of a V65 Sabre showing the location of the springs that commonly go missing. Also note that your air tubes may be routed differently depending upon your model year bike.
A close up of the sync springs and throttle shaft springs (VF750F)
Quick and Dirty Method(s)
The hard way to do a quickie carb cleaning:
- Drain all carbs, then take the gas tank off.
- Separate the fuel line that goes to the carbs right there near the coils.
- Fill the carbs with YCCD or other carb cleaner thru that gas line by gravity feed till the float bowl needles stop anymore fuel flow. Then let sit over night.
- Every so often I like to shake the bike to slosh the fuel in the float bowl.
This method requires doing all the carbs at once, and it requires draining the carb cleaner then refilling the carbs with gas. Actually, I guess if you only drain one carb, then the carb cleaner will only go into one carb.
The easy way to clean the ONE carb causing issues:
Find the offending carb by gingerly testing the exhausts to find out which one is cold.
- Drain that carburetor, then hook a 3/16 clear vinyl tube to the carb drain nipple.
- Fill the carb by filling the vinyl tube carb with 60 CCs of carb cleaner. The carb bowls hold about 50 CCs.
- 60CCs will fill the bowl higher than the fuel level was. I like over filling the float bowl.
This method allows you to run the engine on 3 cylinders until the carb cleaner is replaced with gasoline and the bike is running on all 4 cylinders. I like running the cleaner thru the jets by running the carb cleaner out of the carb.
Some passages are just air passages, Cleaning the fuel areas and passages won't help air passage blockages.
Cleaning air passage blockages:
- Pull the plugs that cover the pilot (idle) screws by drilling a small hole in the aluminum cover. (cover may have already been removed)
- Screw a sheet metal screw in that hole and pull those plugs off. (Be sure you are drilling the right spot - some aftermarket manuals have it wrong)
- Gently screw the pilot screws/jets in until they bottom out (don't over tighten)
- Count the number of turns in so that you can set those screws where they were.
- Bottoming these screws will clean anything off the tips or out of the carb body around those screw tips.
- Resetting those screws to their original setting may cure an off idle running hesitation all by itself.
- I like to carry that one step further, and remove the screw and blow the hole out with compressed air
- Beware of losing the small washer and o-ring on the end of the idle screw.
BTW.......I don't recommend blowing in the Idle screw ports while the carb dip is in the float bowls......
(Courtesy of Pete Springer)
Cliff Koch's Carb Teardown and Cleaning page
- Do not remove the staked throttle plate screws. These are very hard to source. This means that you will be unable to remove the felt throttle shaft washer. This is "OK" for the occasional dunk. However, if you will be dunking the carbs repeatedly in carb cleaner, it is recommended to find a source for the staked throttle plate screws.
- Ultrasonic cleaners work well as a substitution for the carb dip.
- The fuel emulsion tube that the main jets thread into are different between front and rear carbs. There are "low" drilled holes and "high" drilled holes in the tubes. The tubes with the holes located furthest away from the main jet install in the rear carbs.
- The parts list may also show the needles are different front to back. The thinner tipped needles install in the rear carbs.
- If the main jets are different sizes, the bigger jets also go in the rear carbs.
- Short vacuum piston springs install in the rear carbs. Long springs install in the front carbs.