Lower blade does not turn. if i hold it in my hand and shake it while throttling up, it starts to turn. top blade works always.

For twist grip equipped motorcycles to remove the throttle or right side grip remove the upper and lower switch housing screws, loosen the upper screw securing the handlebar clamp to the master cylinder housing. Remove the lower clamp screw with flat washer, separate the upper and lower switch housings and remove the throttle grip from the end of the handlebar. (To remove the throttle grip, a slight tug may be necessary to release index pins in grip from receptacle in seal cap of twist
grip sensor.)

With throttle cables, to remove the throttle or right side grip slide the rubber boot off of each cable adjuster, loosen the jam nut on each adjuster, turn the adjusters in the direction that will shorten the cable housings to their minimum lengths. THEN remove the two screws and separate the upper housing from the lower housing, unhook the ferrules and cables from the throttle control grip and the lower housing, (remove friction spring, throttle friction screw and spring from the lower housing only if necessary), (only if and as necessary mark the position of the master cylinder assembly forward position and split line on the handle bars) (to be safe squeeze the front brake lever and place a 5-32 inch thick cardboard insert between brake lever and lever bracket and then release brake lever to hold the lever in this place to protect the brake switch from damage if the switch housing and the master cylinder get separated) (and only if and as necessary, loosen the two perch screws) move the lower switch housing as necessary and remove the grip.

To install the throttle grip apply a light coating of graphite to the handlebar and the inside surface of the upper and lower housings, (if removed, install the spring, throttle friction screw and friction spring in the lower housing) (and, if removed, attach the cable assemblies to the lower housing), (throttle control cable has a 5-16 inch fitting end and is positioned to the front of the lower housing. and the idle control cable has a 1-4 inch fitting end and is positioned to rear of lower housing. Install the throttle control grip over the end of the right handlebar, position the lower housing onto the right handlebar, engaging the lower housing with the throttle control grip, position the ferrules over the cable ball ends, seat the ferrules (with the cables attached) into their respective notches of the throttle control grip, install the upper housing over the right side handlebar and secure it to the lower housing with the appropriate two screws and hand tighten them, then align the brake master cylinder and perch assembly with the marks made prior to loosening them, and beginning with top screw, tighten the two screws to 108-132 inch lbs using a T27 TORX drive head and then tighten the upper and lower housing screws to 35-45 inch lbs. THEN point the front wheel straight ahead and WITH THE ENGINE OFF, adjust the throttle and idle cables by turning the adjuster in the direction that will lengthen the cables. Gently twist the throttle control grip to the fully open throttle position (fully counterclockwise) and hold it in this position and turn the throttle control cable adjuster counterclockwise until the throttle cam on the induction module (or carb) contacts the throttle cam stop, release the throttle control grip and turn the adjuster counterclockwise an additional 1-2 to 1 turn and tighten the jam nut on the throttle control cable adjuster. THEN turn the handlebars fully to the right and turn the adjuster on the idle control cable counterclockwise to lengthen the sleeve until the end of the cable housing just touches the spring within the cable guide. NOW check the adjustment by, with the throttle friction screw loosened, twisting and releasing the throttle control grip two or three times. The induction module throttle wheel must return to the idle position each time the throttle grip is released. If the throttle does not return to idle, turn the idle adjuster, shortening the cable sleeve until the correct adjustment is obtained, tighten the jam nut and slide the rubber boots over each cable adjuster. NEXT start the engine and with it idling turn the handlebars through their full range of travel and if the engine speed changes at all during this maneuver, adjust the control cables according to the foregoing procedure so that there is no change in the idle speed when the handlebars are rotated through their entire range of travel.


To remove the clutch or left side grip remove the two screws and separate the upper housing from the lower housing. Mark the forward position and clutch perch split line on the handlebars and then as necessary loosen the two clutch perch screws and move it out of the way so that you can access the grip end. If you want to save the grip take a small screwdriver with about an eight inch length and insert it into the grip, wiggling it to loosen the glue somewhat and then spray some brake kleen into the space under the grip where the screwdriver blade is inserted and wiggle and twist the screwdriver around to loosen the rest of the grip glue and pull the grip off. Sand down the handle bar area where the grip will rest and apply grip cement to the area and slip the grip on. If the left hand grip is patterned, align it with the pattern on the right hand grip with the throttle in the fully closed position, immediately push the grip completely onto the end of handlebar using a twisting motion. Do not hesitate when installing the grip or the adhesive may dry before installation is complete. Allow 6 to 8 hours to elapse at 70 degrees F to allow the adhesive to fully cure. If a newer non-glue grip is being installed slip it on with the flats properly oriented to fit with the switch housing halves when they are installed. Install the switch housing halves and lightly tighten the two screws and then orient the clutch perch to the previously made alignment marks and beginning with the top screw, tighten the screws to 108 - 132 inch lbs using a T27 drive head and then tighten the switch housing screws to 35-45 inch lbs.

Lots of saws have left hand threads on the nut that holds the blade in place. It is designed so that if the saw starts up and the nut isn't snug, the nut and the blade slipping on the turning arbor would tend to tighten the nut as they slip against the force of the spinning arbor.
1. Unplug the saw.
2. Hold on to the blade tightly with one hand.
3. Put the wrench on the arbor nut and turn it in the direction you would turn it as if the wrench were turning the blade to cut wood.

If you've previously overtightened the blade, jamb a piece of wood against the teeth and the saw table top and then follow step 3.

If the motor is on the left side of the blade as you face the saw, then it's a standard right hand nut.
If the motor is on the right side of the blade as you face the saw, then its a left handed nut.

Loosen the knob at the rear of the top arm - turn it counterclockwise several turns. The blade should now be loose. Push the "blade end" of the top arm down slightly with one hand while you unhook the top of the blade. Lower the blade a little to unhook it from the bottom arm.

Replace the blade. Hook it onto the lower arm first - you can look underneath to see what you're doing. The blade's teeth should point DOWNWARD - it's easy to accidentally install it the wrong way, so check that now. Again push down slightly on the end of the upper arm, then hook the top of the blade into the upper arm's blade holder. It should how stay in place, but loosely.

Now return to that tensioning knob at the top rear. Tighten it slowly until the blade is BARELY tight, not loose. Tighten the knob 1/2-turn to one full turn tighter to tension the blade.

Lawn mowers usually have some sort of speed governor. Some have an airflow driven flap which controls the throttle linkage, others have an internal bobweight which controls speed.
Check your throttle linkage is operating as it should with the hand control. You may have to remove part of the cowl to see this. Check the engine oil level, some require a certain quantity to make the internal govenor function. If this fails to locate the problem seek more specific help. A manual or parts list should be available online if you dig around.Is it truly running too fast or is the shaking caused by the blade being badly out of balance. Check the blade condition and if in doubt fit a new blade and see how that affects things.

#1) You have to locate the blade release button on the saw (see your manual). The opposite side of the release button is a screw-like OVAL shaped PIN. To insert the blade, the direction( or position) of this OVAL shaped PIN has to match the OVAL shaped hole in the blade. You could use a screw driver to change the direction/position of this OVAL shaped pin. You have to push down the release button when you use the screw driver to turn.

#2) Hold the blade in Vertical position in your right hand. The "Oval" hole is on top. The teeth is facing your left hand. You will see that the "oval" hole on the top of the blade is a "horizontal" oval.

#3) Hold the saw (handle) in your left hand as if you were going to saw using your left hand.
Now peek through the hole of the saw and find the direction of the OVAL PIN. It has to be a "horizontal" (or lied down) OVAL. If it is not, use the screw driver to adjust it.

#4) Hold the blade using your right hand. Oval hole on top, teeth facing your left hand. Insert
the blade from the bottom of the saw. What you needed to do is to insert the PIN into the hole
of the blade. When you inserted the pin into the hole of the blade, slowly turned the blade upward, the blade will lock by itself.

You just need to clean the throttle body. Take the air duct off and hold the throttle blades wide open (engine off). Spray the throttle bores beneath the blades with carb cleaner and scrub with an old tooth brush. clean the back side of the throttle plate also. The junk and gunk is plugging up the air flow past the blade at closed throttle and the idle speed control is running out of authority to open the blade. It just needs a thorough cleaning. Disconnect the negative battery terminal for 30 seconds when you are done to reset the idle learn offsets.

While you are in there and have the blades of the throttle body wide open....see those two tubes sticking up at you from the floor of the manifold?? Those are the EGR delivery tubes and they are NOT supposed to be full of carbon.... Rod them out with a piece of stiff coat hanger wire and carb spray to get them cleaned out.

first unplug the tool, raise the head and loosen the bolt that holds the lower guard in place. DO NOT disassemble the lower guard, pull it down and it will move out of the way somewhat. Next there is a spindle lock that you push in rotate the blade until locked and hold it while removing the hex bolt, which should be left hand thread, I would use a pair of gloves when holding the blade just for safety. Remove the outer flange and spacer (if needed) reassemble in the opposite order and before trying rotate the new blade by hand to make sure turns freely. Let me know if you need more assistance.

its very important that the throttle body especially around the throttle blade be spotless clean or they will stall every now and then. then progress to refuse to idle at all. take off the rubber air intake pipe from the top of throttle body [has 3 torqes screws] open throtle by hand and look for carbon/grease/soot etc were the throttle sits when closed. clean with toothbrush and some caeb cleaner get all black off and dont forget the blade, both sides and the edges. scrub then rinse with carb cleaner untill shiny.spray some cleaner in the hole that is on top off the body to. that is your idle air controll motor port.put back together.it will be hard to start at first so hold gas pedal half way down untill it starts then slowly [real slow] let foot off untill you are no longer pressing it. put in reverse and let it idle there a few seconds then do the same in drive. that should do it. sometimes it may stall a couple of times when driving dont hold foot on gas just let it die then restart this allows the computer to readjust its idle stratagee

on blade you will notice two small phillips head screws. remove both screws with thumb on blade. with other hand remove the blade. Blade has two parts. The smaller blade lays on top of the larger blade. align two blades together. Hold the blade compartment in your hand upward with smaller blade on top of the larger blade. On the clipper in between the two hole where screws go there is a small arm with a round shaped tip. Put the base on to the blades a fixing the round shaped arm into the blades ensure proper fitting. With hand holding the clipper turn over while thumb is holding the blades in place and replace screws.

I had this problem and, after seeing these posts, was motivated to avoid paying the cost of a new blade unit. Here's how it can be fixed:
1. Take a kitchen hotpad and hold the blade (top) side of the unit in your hand as you unscrew the rubber gear on the base. This is a left-handed screw, so you must turn it clockwise, to free it up. This should be doable by hand. Be careful, removing the gear exposes a washer note which side is up, and place both the gear and washer aside.
2. With the blades held in the hotpad, unscrew the top nut, again clockwise. This takes more effort, but it will eventually give way. As this nut comes off, it exposes a rectangular post, to which everything is attached.
3. Remove a washer with a rectangular cutout. Make sure you remember which side is up (I think it makes no difference). This may require some rocking to remove the washer from the round-threaded end. It will come off.
4. Remove both blades in a similar manner. Note their orientation, which is important.
5. Next, remove a rubber gasket. On mine, it has a groove which is asymmetric. I don't think the orientation is important, but, again, you may want to note it.
6. What is left is an axle inside a sleeve. There are no bearings. In mine, I had to tap/drive this out. Take a flat-ended rod (ideas: I used the hex-shaped post end of a nut socket. An old drill bit you don't care about, rotated would also work). Place the unit on the edge of the counter, up-side pointing up, in a way so the bottom end of the axle could fall free when you drive it out. Gently tap the axle through the unit, using the helper tool when the axle is within the sleeve. It will drive completely out.
7. Clean everything. I simply scrubbed the axle and took a small brush to the inside of the sleeve. This doen't need to be perfect, but anything left on either surface may ultimately impair the functioning of the axle.
8. Lubricate the axle with household oil or a dab of grease. You will find that the axle will now slide into the sleeve fairly easily (I had the best luck from the top.)
9. Reattach the base gear, then the top in the obvious order. Everything should spin freely from this point on.
REMEMBER: always use the hotpad whenever you grip the blades and to tighten the bolt on top so that the axle protrudes slightly above the nut.
Good luck!