My engine has got a miss to it. It is at idle and through all driving ranges. I've tried cleaning out the carbs without taking them apart. but, it didn't seem to help.

First make sure there is no water in the gas in the tank or in the carburetor float bowls. If there isn't this is the most likely cause of your problem, assuming you haven't taken anything apart or made any adjustments to the motor : If it hasn't been run in more than one year the slow speed jets in the carburetors are likely plugged up with gummy deposits from old gas. Getting the jets out without taking the carbs off isn't the easiest thing to do and you're usually better off taking the whole carb bank off the engine. Cleaning a bank of four carburetors is not the easiest thing to do either, and must be done very carefully lest you lose or damage the small parts. Even getting the bank off the engine must be done carefully. You can try cleaning just the jets and hope that is all that is plugged, and not the slow speed air or fuel passages as well (depends on how long the old gas was in the carbs and how full the float bowls were). If you get the jets out, do not try to run a wire through them to clean them. Buy a can of carburetor cleaner (not the spray type but the kind in a can with a lid on top) to soak them in, or take the bike to a dealer and have them clean the carbs for you. Make sure when re-installing the carbs that they seat all the way and correctly into the rubber intake manifolds, and that you lightly tension (not too tight) the manifold and air cleaner tubes metal band screws. Make sure the throttle cables are also correctly routed, installed and tightened. Take pictures as you take it apart in case you forget how everything is assembled.

hi there harryandmeli
sounds like you still have a restriction in your carb or the float level is not right
check all the opening s and jets carefully, particularly main jet and emulsion tube air bleeds
and the idle air bleed , and idle jet, is the tank clean and no water ? , is the tank breather working ?, make sure gaskets at carb flange are ok - no leaking of air , make sure air filter is not blocked ?

provided compression and spark ok,( spark should jump a 6 mm gap minimum ) to pass a coil test and fuel flow from tank to carb is good , these engines have hydraulic valve lifters and like 10w/30 kohler oil , everything being = engine should run good

remember F A C T S

F = Fuel , A = Air , C = Compression , T = Timming , S = Spark

take a look

cheers hope it helps

pauly46

I'll assume you can feel the engine misfire by the engine idling rough or "looping". I've had a lot of experience with chevy's "phantom" problems with engine idle,stalling and error codes. This would be the easiest approach to start with. Disconnect the battery for at least 30 minutes to an hour. Reconnect the battery and start the engine. It should idle rough, disconnecting the battery will literally erase the learned idle settings. It will take between 15-20 minutes running in "park" to relearn idle settings, should default to factory settings.You'll need a scanner to erase all the stored error codes to see if the problem reccurs. Another approach would be to check the altenator output and battery voltage, the computer needs a minimum amount of dc voltage to operate correctly. I've been through the filter changes, injector power flushing, fuel pumps, injector rail pressure testing, coil packs, MAF sensor cleaning etc. Its been my experience with 98' and newer chevy trucks, its usually something simple. The ABS light is the one that throws me off, that tells me its electrical. I personnaly would start at the battery-altenator verify voltage. Check PCV valve these were a problem chevy had a technical service bulletin on these. An old school trick, start the engine and let it idle, take a can of carb cleaner and spray around the intake manifold gaskets. if theres a vacum leak the engine will gulp the carb cleaner and stutter briefly. I've had the misfire code on my 2001 4.8L ext. cab in the past. It was always electrical, throttle body, EGR valve related. some cases its the engine crank angle sensor. Consider checking the fuel pressure regulator, on the V-8s its mounted on the fuel rail.

I got rid of my 01' Silverado and traded it in on a 07' 4.8L ext. cab, before i did that I looked under the hood. They've eliminated a lot of the fuel and emission control devices that had all of us scratching our heads and paying through the nose to diagnose and correct. I hope this helps provide some direction, we've all shared your pain at some time.

Unfortunately, you will have to take it apart again and follow these step:

www.fixya.com/support/r6081405-cleaning_small_engie_carburetor

Good Luck!

Jim

When you cleaned the carbs you left the adjusting needles in. Turn the needles in and count the number of turns before they bottom. Write it down for reference as a starting point. You will need to take the carbs apart again and take the needles out as well to reclean them. The needles interact with the jets and when you did the cleaning the first time, it sounds like something got loose and lodged inside. If you want to give a try without taking the carbs off, remove the needles and use the tube from the carb spray to 'inject' the carb through the vent hole. This may force the crud out through the needle holes.

When you cleaned carbs you missed the idle jets one per carb they are very small it takes a small screw driver allso try some sea foam its carb cleaner get it at auto store Hope i was some help MOPAR KENNY

The only way to properly clean is to remove and disassemble. However if you are just a victim of bad gas, a shot of carb cleaner down the fuel line will remove fuel that has gelled in the jet. Know if the clog is more serious, drain the carb bowl, and fuel tank. Pour some Chevron "TECRON" directly into the carb, mix a Shock Treatment ( about a third of cup in one gallon of gas)and put in tank. Start the bike just enough to **** into jets, and let sit overnight.Drain the carb bowls and restart the bike. let it idle or drive it slowly for five minutes. this will usually take care of minor clogs.When bike is idling or running better drive to gas station and fill the tank. Drive the shock treatment through the bike(100 plus miles), this should clean up the entire engine. If the techron does not clean the carbs in 5 to 10 minutes of running time, you will have to take them apart to clean them properly. Use Chevron "Techron" not Chevron "Fuel sytem cleaner with Techron". Techron is more concentrated.

sounds like your throttle cable might be frayed or broken, when you pull the throttle and let go does it go back on its own? and can you here a clicking sound when you close the throttle? If you could send me pictures of the carb how every thing goes in and take it apart and take pictures, that would be helpful.

did u install new gaskets, the engine might be sucking air from outside the carbs. u can use a propane torch (not light) spray a little around outside of the carbs, see if engine sounds different, if it does... leaky gasket.. u might check there is no unplugged vaccum hose.

first how old is your bike, if its older than 10 years, you may have other problems, carbs are pretty basic, if you can start your bike the carb is working fine, there should be a screw or something that controls your idle find it and play with it till you get engine where you want it. clean your air filter, change your oil, and spark plug, make sure you tighten to 8 lbs torque, and make sure its the right plug, and right gap, if it still not idle right take apart your carb and clean it real good, take apart real carefully and have pics of your carb, in parts ordering in case you forget some parts