Echo HC210E hedgecutter carb adjustment woes

[andytw]

I have had this trimmer from new for a long.
To be honest it has always had running issues.
I have always had to tweak the 'H' and 'L' to get it to run and to idle with varying success.
It has had numerous gasket sets over it's life.

Seems, now, to be in it's, deaths throws, very difficult to start, tickover poor to non-existant, but will run flat-out with max throttle so I can just use it.
If I close the 'H' right down I can get a good idle with blades not moving, but obviously stalls if I hit the gas.
If I open the 'H' to say 3/4 of a turn then this impacts on the idle and I have to start closing the 'L' down.
Seems to me the 'H' should not be providing fuel at idle speeds, but it is.

More then happy to get a new carb but don't see even a Chinese copy for sale in the UK.

Ant Any thoughts please.

andytw

[KE4AVB]

Appears to be a WA-148-1 Carburetor.

First the carburetor need disassembly and fully cleaned preferably in a ultrasonic cleaner. This includes the removal of the mixture screws. After which the metering lever set to the correct height and gaskets and diaphragms installed in the correct order.

After installing the mixture screws set them both at 1-1/2 turn CCW from seated. Walbro service manual has this at 1 turn each. This should allow you start the hedger. Start the hedger and let it warm up a few minutes then set the idle speed to where the cutter isn't moving then adjust the L mixture for best speed and readjust idle speed so the cutter stops moving. Sometimes this requires enriching the L mix slightly. From there adjust the H mix at full throttle for best but not exceeding max spec rpm. May also require enriching H mix to stay within specs. I have seen hedgers to shake themselves apart if max rpms are exceeded for extend periods of operation.

And yes both L and H do intereact to a point; just inherit of the design. This is why you adjust first for best idle and then best full throttle speed (not exceeding max rpm). If you don't following the above procedure you will find you willing be constantly adjusting the mixtures. You also can yourself in position where the hedger is too lean and causes cylinder damage.

This assumes that there is no air leaks in the crankcase and intake system which why older equipment need to pressure and vac tested for leaks. Also make sure the muffler's spark arrester screen is clean if in place.

[andytw]

Hi...thanks for your comprehensive reply....appreciated.

I have just been down the strip and clean, and replace route again, in the past hour.
Prior to doing the strip I had seen the adjustment for the needle valve on the Walbro video and on stripping mine I could see this was way off.
Anyways I stripped as far as I was prepared to go and left the welch plugs intact as I am not convinced I could re-fit the new ones. I cleaned out with brake and clutch aerosol down all holes and blew out. It was visually clean to start with.
Have replaced diaphragms and gaskets and new needle and retainer. I have adjusted the needle retainer so the tang is flush with the carb milling. The new one fitted came in about the same as the one removed which would be at least 2mm too high. I suspect I have replaced it in the past and failing to have adjust it may have been the start of my problems.
1.5 turns on each jet and it started and ran and idled. Slight adjustments as suggested and it appears fine. Will see how it goes.

Would say been there before and has it has always had issues but I think the needle valve adjustment may well be crucial.

Thanks

Andy

[KE4AVB]

Would say been there before and has it has always had issues but I thing the needle valve adjustment may well be crucial.

Yes if you are referring the metering needle as if the lever set too low it leans out at idle and if too high it floods or be too rich. Also can cause problems at full throttle though not as noticeable.

[andytw]

Yes the metering needle.