QuestionI bought a honda cbr 600 1994model on last jnue 2004, which was sitting in garage for 1 year(wasnt running ). Tha gas tank was full rust, so I clean it by putting lot of ball bearing and hotwatter. also I clean the carbarotor and plugs in a local workshop. I started using it allmost twise a week till november. and for the last two month I didnt use the bike much. Last week I took the bike to a the honda dealer to change the tires. the bike sit there for another week. and the bike wasn't starting.. The mecanic told me that the bik's all cylinders are not working.. and its running on single cylinder? So.., what should I chkeck with my bike?
AnswerHi Boby,
Check cylinder compression to determine the condition of the engine.
I suspect the fuel in the flaot bowls has varnished again. The engine may be running only on one cylinder because fuel is not passing through the carburetor due to varnishing obstructions in jets and passageways.
You should use a product like Kreem to remove rust and seal the interior fuel tank surfaces. The method described to treat the rusty tank will not work. Once the rust is removed and tank sealed, clean the carbs. Clean the fuel hoses and filters, too. Failure to do this will result with re-contaminated carbs. Do the tank first, and then the carbs. Clean or replace spark plugs amd engine should start and run providing there is no other engine problems.
Respectfully,
Mark Shively
Carb Cleaning 101
By M. Shively
The elements of internal combustion engines are: correct fuel/air ratio, spark at right time, adequate cylinder compression.
There are many passageways and openings to check and clean. All are important in function and when obstructed or not working properly, have subtle to radical effects on engine performance. Vacuum leaks and carburetor synchronization also have effects on performance and should be inspected and adjusted following the below procedures.
Carb Cleaning 101
Warning: Remove all rubber parts before you begin. These parts usually include vacuum diaphragms, needle valves, o'rings, hoses, and other parts. Spray cleaners will damage these parts. Do not disassemble individual carbs from the carb bracket.
Air & Fuel Passageways: Trace and learn individual fuel and air circuits from beginning to end. Machines can only drill straight through the cast passageways. To change direction, another angled passageway must be drilled. The union is plugged with a brass or bronze bead. Inspect and clean each passageway with spray cleaner, brushes/pipe cleaners/etc, and compressed air. Remove any discoloration and debris. Look for spray cleaner to exit from one or more passageways.
Jet Cleaning: Inspect jets by holding to light and look through them. You should see an unobstructed round hole. Clean the jets with one or more of the following: jet cleaning wires, soak solutions, carb spray cleaners and compressed air. Re-inspect jets after cleaning and install when clear of obstructions. Some main jets have paper-like gaskets. Most have metal spacers between the jet and the emulsion tube. Some screw directly into a brass emulsion tube which is machined for a 7mm wrench at its float chamber exposed base.
Inlet Fuel Valve: Inspect the needle valve & spring. Press down the tiny metal rod that protrudes from the butt or float end of the needle valve. The spring should move freely and return the rod to its location. Check the needle valve's seat area for a groove or other wear. It should appear highly polished. Some needle valve seats are rubber and wear may not be visible. Inspect the needle valve jet seat. You can clean the jet seat with Q-tips and semi-chrome polish if necessary.
Carb Body Castings: Blow air through the atmospheric vent holes located on the dome of each float bowl chamber. Air should exit via hoses or brass nipples. Inspect the emulsion tubes and passageways (cast towers that jets thread into) for discoloration and debris. Clean interior emulsion towers with a soft bristle gun cleaning brush. Clean each Venturi (main carb bore).
Needle Jets & Jet Needles: Clean the needle jets, jet needles, and passageway or tower that needle jet screws into. Clean the emulsion tube (pipe between needle jet and main jet) (Main Jet may screw into emulsion tube). Jet needles are part of the throttle slides. See below…
Throttle Slides: There are several types of throttle slides: Mechanical linkage, vacuum, diaphragm, and cable. Disassembling the jet needle from the slide is not always required for cleaning. If you have vacuum piston type throttle slides (large diameter solid metal slide), avoid cleaning the lubrication from sides and caps. If piston type check cap vents and passageways with air. Clean if necessary and re-lube. If you have rubber vacuum throttle diaphragms, inspect for dry-rot, defects, and tears by gently stretching rubber away from center. Do this until all areas around diaphragm have been inspected. Replace any defective part as described above. Clean carb body areas around diaphragm including air passageways and air jets. Diaphragms have a locator loop or tab fabricated into their sealing edge. Observe this locator upon reassembly. Avoid pinching the diaphragm when reinstalling caps.
Fuel Screws: Fuel screws have sharp tapered ends. Carefully turn one fuel screw in while counting the turns until it seats lightly. Warning: These screws are very easily damaged if over tightened into their seats. Record amount of "turns-in" and remove the fuel screw, spring, washer, and o'ring. The fuel screw is part of the enrichment (choke) circuit...clean passageways as described above. When carbs are assembled, spray low PSI compressed air into diaphragm air vents located at intake side of carbs. Throttle slides should rise, then fall when air is removed. Lightly lube external moving linkages. Reinstall carbs and follow through with carburetor synchronization.
Throttle Cables: Lubricate cables periodically. If cables are disconnected from carbs or removed for replacement, etc . . . remember cable routing and ensure proper reinstallation routing. Avoid bread-tying, sharp bends, and pinching cables. Adjust cables so throttle grip has about 5mm of play or throttle slides or butterfly valves may not open completely (full throttle)(wide full open).
Float Bowls: Inspect float bowls for sediment, gum or varnish, crystallization, and defects. Clean all pipes, tubes, passageways, and embedded jets with cleaners and compressed air. Remove and clean the drain screw and area. Inspect bowl gasket and replace if necessary. Clean and inspect overflow pipes and tubes, look for vertical cracks.
Floats: There are several types of float materials: plastic, brass, black composite, tin, and others. Handle floats carefully. Avoid bending, twisting, denting, or other means of mishandling. Most floats are adjustable by bending a small metal tab near the float axle end. Do not change the float adjuster tab unless tuning fuel service levels. Clean metal floats by soaking or by spraying cleaner and wiping clean. Other material type floats may require replacement if cleaning is necessary. Inspect the needle valve (float valve) and seat. Check needle valve's spring loaded pin. It should depress and return smoothly and without resistance. Check the needle valve's tip for a worn groove. Replace needle valve and seat if either symptom exists. These parts wear together and must be replaced as a set.
Synchronization: This is a fine adjustment performed usually and preferably with the carbs installed and the engine running. The unusual part is performed with gauged wire with the carbs on the work bench. Carburetor synchronizing balances Venturi vacuum at the exhaust side of each carburetor, resulting with smooth idling and optimized performance at all throttle openings. Synchronization is checked using a set of gauges which are either air vacuum type or liquid mercury type. The gauges are connected to vacuum ports on the intake manifolds via nipple tubes or if sealed with screws, sync gauge adapters will be needed. With the engine running at temperature, and with a fan or means of forced convection aimed onto the engine, the carbs fuel screws and idle are adjusted, then the synchronization is adjusted via adjustment screws on the carbs. A reserve fuel tank is recommended for convenience of accessing carbs during this procedure. See gauge instructions and repair manuals for detailed use of synchronization gauges.
Notes: While carbs are apart, record the jet sizes. Look for a very small number imprinted on the body of the jets. Verify that numbers are the same for all jets on models with in-line cylinders. A few transverse-4 models and V-engines, the inner and outer carbs use some different size jets and it's important to not mix them up. If you have dial or veneer calipers, measure and record float heights. Perform measurements with floats just touching needle valves, though not depressing the needle valve rods. Replace fuel and vacuum hoses. Be sure to use fuel rated hose for fuel. Install or replace in-line fuel filters. It's a good time to remove and clean interior petcock fuel filters. Inspect carb manifolds for dry-rotting, inspect all clamps and air ducts. Inspect, clean, lube, and/or replace air filter(s).
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How to use Kreem
I have used Kreem w/ v good success, but as with most things in life, the preparation is the most important part. Four important fine points to consider:
#1 - Tank preparation:
The inside of the tank should be completely free and clear of all loose particulate (i.e rust, dirt and sludge). Even more importantly, it must be totally devoid of any and all hydrophobic (oily) substances, including any and all traces of gasoline, oil and grease. To achieve this, I drop two 8" lengths of medium size linked chain into the tank, then pour a small bottle of liquid degreaser full strength in and slosh vigorously with all the openings capped off. Do this good and long, and don't forget to invert the tank and get all of the surfaces degreased up around the filler neck, as well as the very top of the inside of the tank.
Next, add about 1/2 gallon of the hottest water you can get, and add this to the degreaser and the chains still in the tank (don't pour out the degreaser yet... leave it in there) and slosh it around again. The degreaser will emulsify (turn milky white) and hold all of the oils in suspension... this is a good thing. After you are quite certain that you've degreased all surfaces... give it one more slosh just for good luck. Then, pour out the entire mixture and fish out the two chains. After that, pour about a TBSP of hand dishwasher detergent and about a gallon of very hot water into the tank and slosh thoroughly (note: you can use automatic dishwasher detergent here, but as it is formulated to be very low sudsing, it is more difficult to determine when all of the residue has been removed via rinsing.) If you degreased properly in the last step, this wash should produce mongo volumes of suds... also a good thing, as suds are an indication (in this case) that the oily residues (read gasoline) have been successfully removed. Follow by as many cold water rinses as necessary to remove all traces of detergent.
Only now are you ready to phosphate etch the metal in the tank with Kreem kit bottle #1 (Phosphoric acid). Although the directions call for a specific quantity of hot water to be added to the quantity of acid provided, IMO it is better to have a FULL tank of etching solution than to have the exact proportion of acid to water. In the case of an XS650 tank, this amounts to adding perhaps 3.75 gallons of HOT water (3.25 for early tanks) to the acid, as opposed to 2.5 gallons, which (I believe) is the quantity specified in the directions. Again, as in the degreasing step, it is vitally important to have the etching/phosphating solution come in intimate contact with ALL inside surfaces of the tank, including up and around the filler neck. Seal all the tank openings and slosh that bad boy around, but after you're through sloshing, don't forget to slightly crack open the stopper on the filler neck, or the hydrogen gas evolved from the chemical process will blow it out of the hole and across the room, probably splattering phosphoric acid solution on your nice new paint job (don't ask).
#2 - Dewatering:
The small bottle of solvent (Kreem kit bottle #2) is MEK (a close cousin to acetone) and is a very good water remover. After you have thoroughly rinsed the phosphate solution out of the tank, it is time to get things dried up and ready for the polymer coating step. Actually, "Dry" may be a bad word to use here, because the intention is NOT to get the inside of the tank dry from all liquid residue, but rather only to get all WATER residue out. The inside of the tank will still be wet when you are done with this step, but it will be wet with MEK, which is perfectly fine, because that is the same solvent which is used in the polymer to keep it dissolved. Caution: do not dawdle after using the dewatering solvent. IMMEDIATELY go on to the polymer coating step. If you wait too long before you go to the next step, you may "flash rust" the inside of the tank, which will require starting over. If the inside surface of the tank begins to physically dry out, you're taking too long and are in danger of forming flash rust. Get you ass movin' boy!
#3 - Coating:
Conservatively speaking, there is enough polymer in bottle #3 to do AT LEAST two (probably three) XS650 tanks. What this means is that, unless you have two or three tanks prepped all at once, you are going to not use all of the polymer provided in the kit. You must remove the excess polymer from the tank that you are working on. Follow the instruction very carefully here, rolling the tank around for a few minutes, then letting it set on one side, followed by rolling around again and letting it set on another side, repeating until you are secure in the fact that all interior surfaces have been thoroughly coated. After that, you MUST pour out any remaining polymer, or you will have a puddling problem. Even after you pour out the excess, you must continue the process of rolling the tank and then letting it set on alternating sides, while the remainder of the polymer still in the tank forms a non-moving film.
#4 - Drying/curing time:
Probably the one most crucial mistake leading to premature failure of Kreem coatings (after improper degreasing) is insufficient drying or curing time before putting the tank back into service. After you are satisfied that the majority of the polymer in the tank has skinned over, follow this procedure:
Remove all stoppers from all openings, both top and bottom (filler & petcock holes).
Turn the tank upside down (preferably on a hot surface like your black asphalt driveway at noon in July (January if you're in Oz) and block it in place so the filler neck is facing vertically straight down. Then, rig up a small air pump and hose and stick the hose into the tank from the underside through the filler opening, being careful not to allow the hose to touch the inside surfaces. An air pump from a fish tank fits this bill perfectly. Turn on the pump and let the forced air dispel the vapours from inside the tank, which will aide drying and curing. After a few hours, you will no longer be able to smell vapours coming from the tank. It is then safe to move the tank, but DO NOT use the tank yet. Move the whole rig up into your hot, oven-like attic and allow the air pump to run for another two days minimum, with the hose still in the tank. One day is probably enough, which is why I always do it for about a week just to be sure. It pays to watch the weather and plan to Kreem the tank on a day that is going to be sunny, hot and dry, if at all possible.
If you add the above tips to the (already pretty good) instructions included with the three part Kreem kit, you will end up with a well sealed, carefree fuel tank for many years to come. Good luck!
Bill in Yardley, PA
