HS 85 bogs when revving

I

ipbr21054

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Ive been using this all ok but today when i tried to start it i wasnt able to rev it without it bogging then stalling.
I only used it say 6 times & filters / plug / fuel are all new.
Carb was also cleaned

Where should i be starting to have it running like it should.
 
Thanks but didnt help me out.
Ive taken the carb off & cleaned it out but it was ok anyway.
I managed to get it to start & run to a fashion enough to cut the hedg, this was only with choke 1/2 on all the time.

Ive now ordered a carb with 3 adjustment screws to give me more control as the carb fitted only has 1 screw of which now doesnt really do anything other than allow the item to stall when touched
 
If the machine worked better with some choke then there has to be some degree of fuel starvation.
This is due to either a partial blockage - maybe in the tiny filter just above the needle valve - or some deterioration in the pump or metering diaphragms.
You’ll rarely see carburettor faults, and it takes an experienced eye to tell if the diaphragms are likely to give problems.
John
 
Im sure that the carb isnt blocked as used carb cleaner & a lot of it.
The diaphragm which has the metal part attached seemed flimsy.
This part is the one that is sat on top of where i undo the phillips screw & check viton needle tip & has that slim bar holding down the spring.

I agree its starved but the only screw when touched dont realy do anything so i order a carb
 
The diaphragm you are referring to is the metering one, the pump one is at the other end and has two U shaped flaps.
The needle valve lever, operated by the metering diaphragm needs to be parallel with the carb face.
The gauze filter - often blown away without people noticing - is directly below the needle valve tip.
Just a few points for info!
John
 
New Chinese carb arrived & fitted.
Second pull of the rope & started.
I’ve let it warm up & then grabbed the throttle lever. Adjusted the H screw so it’s now running great at full throttle.

The other 2 screws are ticker over LA screw & running screw at idle L screw.

How should I be adjusting these & in which order.
I ask as I see the blades slightly operating at tickover & think this isn’t right.
 
Turning the L screw clockwise weakens the mixture and the machine should speed up a little.....although it won’t have any power to accelerate.
Turn the L screw anti-clockwise richens the mixture so do this until the engine starts to slow down, then clockwise again to the position where the engine is about to slow down - if you get my drift!
The engine should accelerate well here as it’s getting plenty of fuel.
Adjust LA screw so the blades are just not moving.
John
 
If you're not using the thing all that often, run it on the good fuel (my garden tools all get Shell Vpower out of the bikes). There's a link in here somewhere to some pukka garden fuel.....
 
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