My still brush cutter FS85 starts perfectly but the blade won't spin when I pull the throttle on. Seems the throttle is disconnected.

Shear pin (connects the blade to the shaft ) is broken.

It is possible that the timing gear jumped a tooth. Take off valve cover and check to make sure timing marks line up. Other than that check other things like carb adjustment, good gas, air filter and other general tune up things.

check for bent crankshaft at blade connection point. do this by removing spark plug and turn the mower on its side with carburator side up, now spin blade by hand and see if it will spin without a wobble. if it does not want to move, something else inside the engine is damaged and probably not worth fixing. if the blade does not spin true, it is a bent crank and might be able to be straightened by a mechanically inclined person without further damage to the motor. also check to see if the piston is moving while spinning the blade if it will turn at all. R

This problem can be caused by the brushes wearing out. Check brushes first. If you need to clean the commutator it is best to remove the armature completely and use a scouring pad similar to what you would wash your plates with. You can use wire wool, and if you do (it is quicker and a bit more thorough) make sure you clean between all the comm segments after with a stanley knife or something so there is nothing left to short across them.
The really professional way to sort the comm is to 'skim' it on a lathe, which would mean spinning it up on a lathe and smoothing it out with a hardened cutter. This also leaves the comm nice and flat, ready for new brushes, but should only be done by a competent person as it can go wrong quite easily. Also after skimming you should cut back the insulation slightly so there is a nice step between segments.

call the company that you bought it from or the manufactor might have it yet so they can send it to you.

http://www.mediafire.com/view/9duor5dwblekisn

Hi there,

Sorry to hear you're having difficulties with your DC14. If the brushbar won't run when the cleaner is in contact with the carpet, it's probably best if you get in touch with us directly. One of our experts will be happy to run through some troubleshooting over the phone with you, and recommend the best course of action. You can call us free on 08002980298 (UK), or 1866MYDYSON (US). We'll look forward to hearing from you.

Kind regards,

Jack
Dyson Customer Service

You need to quickly throttle (left joystick) all the way down whenever you're about to crash or blade strike. Both motors have clutch to spin freely when in neutral. They will bounce off of anything if they can, i.e. if your hand isn't still pegging the throttle. But, if the blade (or blades) hit something that stops them while throttle is still being applied, one of three things will happen.
1) Blade will stop abruptly, putting grossly abnormal strain on the motor and those tiny little brushes inside. Motor may burn out. Every fraction of a second that throttle is being applied while blades cannot move, irreparable damage is almost certainly being done to the motor(s).
2) Blade(s) will break, maybe taking gears or shaft along for the ride.
3) or sometimes nothing seems to have happened, bird clunks to ground, you right it and continue flying.

however, if you throttle fully down, the motors engage clutches automatically and are effectively in neutral, spinning freely allowing the blades to bounce harmlessly off of whatever.

Throttle down when accident nears, and your motors will last for ages.

Hope this helps,
r

Hi sounds like it could need a diaphram kit in the carby if it has mixture screws one markedl for low speed and one marked h for high speed you can try winding out the low speed screw a bit but if that does not work it will definatly need a kit.

it might have a easy start that wound make it seem like its sliping.change spark plug and gap at 030.see if it helps if not rebuild carb.
good luck