Question about 1980 Yamaha XS 400

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How do i begin adjusting the carbs? - 1980 Yamaha XS 400

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1st-clean air filter and oil,fresh plugs,good fuel,valves adjusted correctly,check for tears or cracks in intake boots,fire in all cylininders;minimum compression & w/in10% of each other in all cylinders, and no exhaust gasket leaks. once these components are w/in specs. and operable the carburators can be adjusted, as long as they are internally clean and operating as designed.1st- set high idle, then set idle rpm, now synchronize vacuum on carburator set,now readjust idle rpm.

Posted on Feb 19, 2009

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Hey I have a 1974 Honda CB200 which runs with two carbs but i am having difficulty in tuning them right . fuel efficiency is poor . So i want to ask you if i can replace those two carbs with one carb like...


The power would not be changed. If the distance between the intake ports is the same, you should be able to do the swap. That air filter will need to be changed also. Before you spend money, how about spending a little bit of time instead? Remove the carbs then remove the float bowl at the bottom of one of the carbs. Only work on one carb at a time. Remove the air and the throttle screws. Now use spray carb cleaner to clean the inside of the carb. Spray into every fitting and drill hole you can find. Spray from both ends of a fitting or hole if possible. Put the float bowl back in place and then put the air and throttle screws back in. Turn them inward until they LIGHTLY seat. Noe turn each of them outward one and one half turns. Now clean the other carb the same way...
Mount the carbs back on the bike. First, synchronize the two carbs so that the slide in the center of both carbs begins to raise at the exact same moment when the throttle is twisted. The motor is turned off for this adjustment. Use a mirror to see the slides when the throttle is gently turned. Adjust the cable fitting on top of the carb that is latest to begin to lift, turn the fitting outward. Start the bike and then adjust the throttle screws equally to set the idle speed. It would be a good idea to balance the carbs also. I can tell you how in a reply. Answers that are too long get cut off by Fixya.



Aug 15, 2011 | 1974 Honda CB 200

1 Answer

Honda tiller F110 runs good with thr aircleaner off. Put new aircleaner on and stops running . Any soulition


Carb could be starved for air. try cleaning carb with carb cleaner. This may not be problem to begin with,. Check plug gap, should be 0.28, sometimes this gets out of adjustment.

Mar 09, 2011 | Garden

1 Answer

How do I adjust needle valves on a 25cc Homelite UT08111A Backpack leaf blower?


Set the lowend & highend needles to about 1 3/4 to 2 turns each. Choke the carb or prime it, until the carb is wet. Fire up the engine and let it warm up. Let's set the topend first since it's the easier of the two. Go to full throttle. Adjust the topend needle for peak RPM. Leave it wide open for about a minute to see if it changes any. Should the engine go lean, open the lowend needle slightly, if this dosen't work... you will have to adjust the needle valve inside the carb.( I will explain this later) If the topend runs OK, then slowly pull the throttle down until the engine begins to "four cycle" hold the throttle there. Adjust the lowend needle until the "four cycling" barely stops. Now lower the throttle more until it "four cycles" again, and adjust the lowend again. Keep doing this until you reach full idle. Now, from full idle begin to throttle up until the engine starts to bog or hesitate. Open up the lowend needle just enough to eliminate the bog or hesitation.

http://tech.flygsw.org/walbro_tuneup.htm

hope this helps :)
if it does please vote

Oct 23, 2009 | Homelite Consumer Products Backpack...

1 Answer

Need adjustments for 88 model carter 2 barrel carburator. fits 4.2 jeep


To set carb adjustment, first set timing correctly, then put both a vacuum gauge and tach on the engine. adjust one idle screw to highest vacuum reading and highest tach reading, then do the other one. go back to the first and re-adjust again, then the other. I find that if you have a mechanical screw or a solenoid that holds idle speed on the linkage, turn them back so that engine is idling at the lowest possible rpm without stalling before making adjustments, then when finished, bring idle rpm up to recommended rpm using those. On an older carb, usually the idle screw covers have already been removed. If not, you need to remove them before you begin, usually best done with carb on a bench.

Oct 06, 2009 | 1988 Jeep Wrangler

1 Answer

Fuel lines!


Sounds like you need to adjust the carb. Remove the caps from the carb. Turn both screws clockwise until all the way seated. Start the trimmer and while running begin to back out the screws slowly until the trimmer is running strong but is smooth. Once you have the carb adjusted you can put the caps back on or you can discard.
Good luck!

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I need to know how to adjust the carbureator on an tecumseh lawn mower model number 143.954500


If it has a float type carb, open it 1.5 turns. If it has a diaphram open it one turn. If it has a Walbro carb, there is no adjustment. Once you get the engine started you may adjust the carb to fine tune. Open until it begins to lose RPM's then close until it starts to lose RPM's. Return to a point between the two. Good luck...Lee

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Ryobi SS30 Carburetor Problems


Replace thecarb screen, make sure you can see through the screen

Aug 18, 2009 | Ryobi Garden

1 Answer

Honda cr 125 1997 wont idle


Your carberautor is either gummed up or needs to be adjusted. Begin by going to an auto zone or similar store and gatting a can of carb. cleaner that gets added to your gas. Be sure to follow the instructions on how much you add per gallon. let that run through your bike for a while and see where you are. If cleaning the carb. doesn't hellp, then the carb. will have to be adjusted.

May 27, 2009 | 2002 Honda CR 125 R

1 Answer

Timing Adjustment issues!


If the bike runs then Top Dead Center (TDC) is not an issue. But to check piston stroke position, Remove the valve cap cover on the intake of the front cylinder. Remove both the spark plugs. Rotate the crank shaft untill the rocker arm starts to move. The piston is now starting down on the intake stroke. Rotate the crank further and the rocker arm moves in the opposite direction. The piston is now going upward on the compression stroke. Look at the marks on the flywheel. Rotate the crank untill the TDC mark lines up with the timing index mark. The front piston is now at TDC.

If your model has carbs then the backfire fix requires you to syncronize and balance the carbs.
SYNCHRONIZE THE CARBS
Remove the air filter and rubber fittings to allow you to see into the throat of both carbs. You may need a mirror to see inside. You need to be able to see the slides go up and down when you twist the throttle. Now turn the fitting where the cable goes into each carb such that there is just a bit of slack in the cable, 1/16" is plenty. Lock ONE of the cable adjusters down tight. All further adjustments will be made on the other carb.

With the motor turned off twist the throttle very slowly while looking at the slides. Both slides need to begin lifting at the exact same moment. If the slides don't raise at the exact same time then slowly twist the throttle until the locked adjuster slide just barely starts to move. Hold the throttle still and turn the adjuster on the other carb so that the slide on that carb just barely starts to move also. Now recheck the slide movement timing. Do this process until the slides on both carbs begin to raise at the EXACT same moment. Lock down the loose adjuster and re-check the slides.

BALANCE THE CARBS
Turn the throttle screw on the LEFT carb one half turn inward. Now start the engine and get it warmed up. With the engine running, remove the RIGHT spark plug wire. Adjust the idle speed on the left carb to the point where the engine just can't quite stay running and dies. Now put the loose spark plug wire back into place.

Now turn the throttle screw on the RIGHT carb one half turn inward. Restart and rev the engine. Next, remove the LEFT spark plug wire. Adjust the idle speed on the right carb to the point where the engine just can't quite stay running and dies. Now put the loose spark plug wire back into place.

Turn the idle screw on each carb EXACTLY ONE QUARTER turn outward and restart the engine. The engine will be probably be idling very fast. Adjust both the idle screws equally from this point to get to the desired idle speed. Congratulations, you have just balanced and synchronized your carbs.

Please rate this solution. Thanks sgtswampdonk!

Apr 02, 2009 | 1999 kawasaki VN 800 Vulcan Classic

1 Answer

Honda 1300c backfire through carb at wide open throttle. I have open up the exhust and rejetted the carb . the bike will run fine up to mid throttle or 65 mph but if you accellerate hard or go to wide open...


Try balancing ans syncronising the carbs.
BALANCE THE CARBS
Turn the throttle screw on the LEFT carb one half turn inward. Now start the engine and get it warmed up. With the engine running, remove the RIGHT spark plug wire. Adjust the idle speed on the left carb to the point where the engine just can't quite stay running and dies. Now put the loose spark plug wire back into place.

Now turn the throttle screw on the RIGHT carb one half turn inward. Restart and rev the engine. Next, remove the LEFT spark plug wire. Adjust the idle speed on the right carb to the point where the engine just can't quite stay running and dies. Now put the loose spark plug wire back into place.

Turn the idle screw on each carb EXACTLY ONE QUARTER turn outward and restart the engine. The engine will be probably be idling very fast. Adjust both the idle screws equally from this point to get to the desired idle speed.

SYNCHRONIZE THE CARBS
Remove the air filter and rubber fittings to allow you to see into the throat of both carbs. You may need a mirror to see inside. You need to be able to see the slides go up and down when you twist the throttle. Now turn the fitting where the cable goes into each carb such that there is just a bit of slack in the cable, 1/16" is plenty. Lock ONE of the cable adjusters down tight. All further adjustments will be made on the other carb.

With the motor turned off twist the throttle very slowly while looking at the slides. Both slides need to begin lifting at the exact same moment. If the slides don't raise at the exact same time then slowly twist the throttle until the locked adjuster slide just barely starts to move. Hold the throttle still and turn the adjuster on the other carb so that the slide on that carb just barely starts to move also. Now recheck the slide movement timing. Do this process until the slides on both carbs begin to raise at the EXACT same moment. Lock down the loose adjuster and re-check the slides.

Please rate this solution. Thanks!

Mar 30, 2009 | 2004 Honda VTX 1300

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