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Carburetor Maintenance

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Carburetor maintenance
I have used this procedure for over 15 years on all types of carburetors from lawn mowers to high performance cars and have always had good results as long as the carburetor was in good mechanical order. Cleaning the carburetors will not help a carburetor with a worn nozzle or a leaky diaphragm on a slide. The carburetor cleaner I use is berryman b-12 chemtool in the spray can and the pint size can, but any good carburetor cleaner should work if you can get it in a spray and pint can.

Cleaning the carburetors
Place the bike on the center stand and remove the cover of the air cleaner and the filter exposing the top of the carburetors, start the engine and open the throttle to make sure the slides are all moving; if one or more of the slides fails to move you may have a broken diaphragm or a clogged jet. Use the spray can to clean the insides of the carburetors spraying into the jets at the top and the throat of the carburetors . If the engine stalls restart and continue until it looks clean. Replace the filter and cover, now turn the gas tank valve to the off position and restart the engine and run it until it stops. Remove the supply hose (top hose) from the fuel pump and replace it with a suitable sized hose long enough to reach the ground and put it into the pint can of cleaner. Now turn the key on and allow the fuel pump to fill the carburetors before trying to start the engine. (note the fuel pump has a safety feature and you may have to turn the key off and on until the pump fills the carburetors) Start the engine using the choke to keep the engine running about 1000 rpm and allow it to run for about 5 min., then go get a cup of coffee or clean the outsides of the carburetors to use up the can of spray, waiting about 20 min. Restart the engine and (*) use the throttle to increase the rpm and work all the moving parts of the carburetors, the run for 4 min. and wait for another 20 min. if you used the spray on the outside of the carburetors be sure to re- oil the moving parts with a light machine oil and if all of the slides worked when you tested them you can re connect the fuel line while your waiting. when the time has past you can turn the gas valve to the on or reserve position and open the drain valves on the carburetors (lower right on each carburetor) when the carburetors are empty close the valves and turn the key on to fill the carburetors with fuel. also if you are storing the bike for the winter you could drain the carburetors and not restart the engine.

(*)IF one or more of the slides did not move when you tested them you should re-test them at this time by removing the air cleaner cover and filter and watching the slides. If one of them are still not moving, note the problem slide and turn off the engine. Remove the cover plate and inspect the diaphragm then carefully remove the spring and slide from the carburetor. Before continuing we suggest you use eye protection. You will see a jet in the upper right side of the opening place the nozzle of the spray can against this jet cover the opening with your hand so that the excess spray won't get in your eyes and give it a good shot; cleaner should come out of the top of the carburetor. if it seems clear then wipe off the slide and the hole it came out of and reassemble the slide making sure that you replace the diaphragm exactly as you found it! Fred J. Vogt



Throttle cables
The throttle cables on the Venture can cause you some grief if they brake on your vacation or even on a 100 mile Sunday ride if your 50 miles from home. There are four cables that are used to control the carburetors and they use a push/pull method; that is they use a positive return on the throttle that dose not rely on the return spring to shut down the carburetors. there is a fifth cable that is used by the Venture curse which will disable the curse if it fails. all five cables connect together at the control box and you can view it by looking up behind the left hand fairing at the front of the bike. I have not found a way to replace these cables with out removing the left fairing, radio and the black plastic shield behind the radio. This could be done with the tools in the tool kit supplied with your Venture, so you could repair the cables if you had a spare. Although any of the five cables could brake, most of the failures I have heard of are the two cables that connect the hand throttle to the control box. these cables normally fail at the hand throttle on the handle bars because they are worked more and are exposed to water and dust, more then the ones at the control box because the cables are in side. If the return cable brakes it will not stop you, but you will notice that the Engine will lose RPMs slower than normal and the hand throttle will feel funny. Maintenance of the cables is simple and should be done every 10,000 miles or once a year. To check and oil the throttle cables disassemble the hand throttle, clean and use A drop of light machine oil (sewing machine oil) work it in and reassemble the throttle. Just in case you have a problem before you get a chance to check the cables here are some thoughts on how to get home or to a repair shop. You could use the choke lever to increase the RPMS then get the bike over 35 mph, set the curse and use it to increase your speed. You could also get the MTS towing package offered through MTA and be only a phone call away from help.

Fred Vogt

MTA 1037

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