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Difficulty adjusting carb for smooth idle and full power tilling
Mantis idles poorly and bogs down when applying full power. Have diddled the red and white carb screws according to the manual, cleaned muffler screen, changed spark plug. Next step is to check gas-oil ratio with a new batch of mix. Any ideas on carb adjusment. Manual not very helpful
screw all screws all the way in. then unscrew each 1-1/2 turn each. adjust the H screw first to get a good idle then adjust the L to get a good steady but not too high throttle. i hope this helps. if it bogs and then dies after full throttle it may be internal damage in the engine(rings/valves).screw all screws all the way in. then unscrew each 1-1/2 turn each. adjust the H screw first to get a good idle then adjust the L to get a good steady but not too high throttle. i hope this helps. if it bogs and then dies after full throttle it may be internal damage in the engine(rings/valves).
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Re: difficulty adjusting carb for smooth idle and full...
Your quickest fix for this problem is to simply replace the carburetor, a Zama K54A. Do it all the time. After that, if you can find a 2 cycle oil, Opti-2, it's the best you can use and it's a one mix for all your 2 cycle equipment (blowers, trimmers, chainsaws, etc.) It's the only 2 cycle I sell in my shop.
Re: difficulty adjusting carb for smooth idle and full...
Bought a mantis 7222 used drained old gas changed the plug starts and idles fine but when under full throttle wants to die acts like running out of fuel if i feather the accelerator will continue to run any ideas
Re: difficulty adjusting carb for smooth idle and full...
First thing about these little tillers is they are not very powerful and the smallest of vines or roots rapped abound the axel mount for the tiller wheels will feel as though you have a motor problem. I have had mine since 1985 and i still get fooled from time to time by tightly rapped roots, even the small ones. Check it see!
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search --workshop manual for Walbro carburetors
down load the pdf version
search --workshop manual for Zama Carburetors
down load the pdf version
the high speed needle is set first ( one closest to the air filter) to obtain smooth high rpm running then the idle needle ( next to the engine ) is adjusted as you slowly slow down the rpm
final idle speed is achieved by adjusting the throttle screw and should be just slow enough that the centrifugal clutch is not engaged
Zama Carb? Turn both low and high meter screws 2 full turns counterclockwise, and idle speed control to maximum. Prime unit and start motor. Run for about ten seconds and then turn idle jet (clockwise) for maximum rpm and then lower idle rpms - readjust idle meter as necessary along with idle screw. Then gun unit at high speed and turn high screw for maximum rpm. Go from idle to max and make sure there is a smooth transition. If not play a tad with the idle mixture screw till that is achieved.
hello ,your engine is a tecumseh HMSK90-156525D, Sounds like carb. may need adjusting. Take the heat box off to expose carb. the heat box is the metal box surrounding the caeb., there should be 2 adjustment screws- 1 on the bottom of the bowl and 1 on the side of the carb just above the edge of the bowl ( depending how the carb sets off the engine - if the carb comes straight out it will be on the side facing towards the front of the snow blower or if it goes towards the handles then standing other side of the snow blower the screw will be facing you), turn both screws in til they just bottom out the turn them out 1 1/4 turns out then start the machine. While the machine is running at low idle turn the screw on the side of the carb. in (clockwise) a little at a time listening for the engine to start to rev up and then start to rev down, bog or studder then turn back slightly to bring idle back up. Once the idle is up then the screw on the very top of the carb. turn that out to lower idle to a normal idle. Repeat those adjustments till you cant get the idle to go up anymore. Now for the screw on the bottom of the bowl- move the throttle up to max and turn the screw in till you hear it rev up higher and starts to bog or sputter then turn it back slightly to bring the high rev to a smooth rev. That should take care of it. If it does not solve it then the carb may need cleaning then the adjustments done again. If you need more help on this please feel free to ask. Sometimes you have to do process of elimination and you start with the easiest first. Also the adjustments should help with the carbon build up on the plug.692509.pdf (application/pdf Object) i have included the manual to give you a good understanding of the carb, page 7 to 25, hope this helps,don't forget the 4 thumbs up,any comments welcome,thank you.~~
hello ,your engine is a tecumseh HMSK90-156525D, Sounds like carb. may need adjusting. Take the heat box off to expose carb. the heat box is the metal box surrounding the caeb., there should be 2 adjustment screws- 1 on the bottom of the bowl and 1 on the side of the carb just above the edge of the bowl ( depending how the carb sets off the engine - if the carb comes straight out it will be on the side facing towards the front of the snow blower or if it goes towards the handles then standing other side of the snow blower the screw will be facing you), turn both screws in til they just bottom out the turn them out 1 1/4 turns out then start the machine. While the machine is running at low idle turn the screw on the side of the carb. in (clockwise) a little at a time listening for the engine to start to rev up and then start to rev down, bog or studder then turn back slightly to bring idle back up. Once the idle is up then the screw on the very top of the carb. turn that out to lower idle to a normal idle. Repeat those adjustments till you cant get the idle to go up anymore. Now for the screw on the bottom of the bowl- move the throttle up to max and turn the screw in till you hear it rev up higher and starts to bog or sputter then turn it back slightly to bring the high rev to a smooth rev. That should take care of it. If it does not solve it then the carb may need cleaning then the adjustments done again. If you need more help on this please feel free to ask. Sometimes you have to do process of elimination and you start with the easiest first. Also the adjustments should help with the carbon build up on the plug.692509.pdf (application/pdf Object) i have included the manual to give you a good understanding of the carb, page 7 to 25, hope this helps,don't forget the 4 thumbs up,any comments welcome,thank you.00
hello ,your engine is a tecumseh HMSK90-156525D, Sounds like carb. may need adjusting. Take the heat box off to expose carb. the heat box is the metal box surrounding the caeb., there should be 2 adjustment screws- 1 on the bottom of the bowl and 1 on the side of the carb just above the edge of the bowl ( depending how the carb sets off the engine - if the carb comes straight out it will be on the side facing towards the front of the snow blower or if it goes towards the handles then standing other side of the snow blower the screw will be facing you), turn both screws in til they just bottom out the turn them out 1 1/4 turns out then start the machine. While the machine is running at low idle turn the screw on the side of the carb. in (clockwise) a little at a time listening for the engine to start to rev up and then start to rev down, bog or studder then turn back slightly to bring idle back up. Once the idle is up then the screw on the very top of the carb. turn that out to lower idle to a normal idle. Repeat those adjustments till you cant get the idle to go up anymore. Now for the screw on the bottom of the bowl- move the throttle up to max and turn the screw in till you hear it rev up higher and starts to bog or sputter then turn it back slightly to bring the high rev to a smooth rev. That should take care of it. If it does not solve it then the carb may need cleaning then the adjustments done again. If you need more help on this please feel free to ask. Sometimes you have to do process of elimination and you start with the easiest first. Also the adjustments should help with the carbon build up on the plug.692509.pdf (application/pdf Object) i have included the manual to give you a good understanding of the carb, page 7 to 25, hope this helps,don't forget the 4 thumbs up,any comments welcome,thank you.~~
After seating the screws back them out 1 1/2 turns. This should be close enough to get it started. Let the motor warm up a little then, with it idling, turn the low screw in until it starts having a hard time running then back it out until it idles smoothly. Prop up the Mantis so it can run at full speed safely while you adjust the high side. With the throttle wide open, again turn the high screw in until it starts running roughly and back it out until the motor is running smooth. Some say to turn the screws out until the motor starts having a hard time running and then turn it back in half way to where it was running bad at the other end. This doesn't work as some engines don't care how far open the screws are.
Usually that is a sign of the carb not being adjusted right. Run it at full throttle and adjust the main mixture needle (usually on the bottom) until it runs the smoothest. Set it in the middle of the range where it runs smooth. Then set it down to idle and adjust the idle mixture until it runs smooth at idle. Accelerate it rapidly and if it bogs or hesitates turn the idle mixture a little leaner (clockwise) and try again until it works right. That should get you very close. Try tweaking it a bit from there. as the microscopic specks clean out of it, it may need more adjusting.
gap should be about .020 - Carb setting is adjusted while running - lo idle and hi - lo idle adjusted to the lowest RPM before it stalls or starts running rough, the hi is adjusted at full throttle for the smoothest / highest rpm
Sounds like carb. may need adjusting. Take the heat box off to expose carb., there should be 2 adjustment screws- 1 on the bottom of the bowl and 1 on the side of the carb just above the edge of the bowl ( depending how the carb sets off the engine - if the carb comes straight out it will be on the side facing towards the front of the snow blower or if it goes towards the handles then standing other side of the snow blower the screw will be facing you), turn both screws in til they just bottom out the turn them out 1 1/4 turns out then start the machine. While the machine is running at low idle turn the screw on the side of the carb. in (clockwise) a little at a time listening for the engine to start to rev up and then start to rev down, bog or studder then turn back slightly to bring idle back up. Once the idle is up then the screw on the very top of the carb. turn that out to lower idle to a normal idle. Repeat those adjustments till you cant get the idle to go up anymore. Now for the screw on the bottom of the bowl- move the throttle up to max and turn the screw in till you hear it rev up higher and starts to bog or sputter then turn it back slightly to bring the high rev to a smooth rev. That should take care of it. If it does not solve it then the carb may need cleaning then the adjustments done again. If you need more help on this please feel free to ask. Sometimes you have to do process of elimination and you start with the easiest first. Also the adjustments should help with the carbon build up on the plug.
screw all screws all the way in. then unscrew each 1-1/2 turn each. adjust the H screw first to get a good idle then adjust the L to get a good steady but not too high throttle. i hope this helps. if it bogs and then dies after full throttle it may be internal damage in the engine(rings/valves).
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