Temperamental FS200

[difflock]

About 10 years old, never saw that much use, has on occassion been left parked up with fuel in the tank, brought out this morning and started virtually first pull. Stopped and restarted a few times with strimmer line problems, refilled the tank, restarted and then I stopped it again, and would NOT restart until stone cold. And it will only run flat out, and died when I unblipped the throttle.

I mean it will not even cough, and the plug threads were always wet when I pulled it a few times.

Guessing it is carburetor related?

So strip down and clean?

I know zero about 2 strokes and have never disected one before.

In hindsight, it started without the choke 1st thing this morning, after I pumped the primer bulb.

Marcus

Edited Wednesday at 18:15 by difflock

[spudulike]

Difficult to tell but your description of the engine not starting until stone cold could be that the engine has low compression and it is dropping off further when warm and making it hard to start. You can measure it with 150psi+ being OK, you can take the exhaust off and inspect the condition of the piston and when there, check the exhaust port isn't clogged with carbon.

The cooling down thing can be a dodgy coil or the flywheel to coil gap being too large. You can regap the coil to flywheel with thin paper and this may get a weak spark back up to full tilt.

Other than that, the fact the plug is wet may mean the needle valve is leaking letting through too much fuel and flooding the saw but can also mean the engine is just not firing on start up so very difficult to tell.

A carb rebuild is my normal start but do check the spark by removing it, earthing the plug on the cylinder and pulling it over to test but make sure the plug is away from the plug hole as you can get some pretty spectacular flames from ignited fuel from the plug hole.

In the carb, make sure the needle and spring are sealing correctly, the metering diaphragm is soft and flexible, the pump diaphragm isn't deformed and the flaps are not holed and finally that the gauze strainer isn't full of chip.

[green heart]

Marcus,

We've got an old FS200 with an identical issue.

It still runs like a new machine, till you stall it, and then needs me to go and drink a cup of tea, before it will restart..

Not having Spud's expertise, we just put it down to poor compression, and enjoy regular tea breaks, if we have to use it !

[difflock]

I went out after dark to lock it away for the night, and tried her.

First fornicating pull and away she went, the bitch!

But again, no choke applied, though the pistol grip throttle start setting was engaged. 

For the limited use, on good mix, I could not imagine the compression should be poor, and it still feels pretty tight to pull over TDC.

Thanks all.

[difflock]

And tried her this morning,  and the air filter was swimming in fuel.

Stripped the carb down, removed the two diaphrams and blew through any orifice I could see or find.  Reassembled, and no different, started, ran, then died when the throttle unblipped, and fuel swimming about the lower reaches of the air filter housing.

P.S.

Piston is spotless and oily smooth, and a strong enough looking spark. In today's sunshine.

So off to J Whyte it is.

[spudulike]

Ah, the symptoms of excess fuel and not needing choke on cold start like you have are generally contributed to the needle valve not sealing up correctly. This could be a hardened diaphragm, weak needle spring, worn needle or just a poorly adjusted needle arm.

A full carb kit may well sort out the issues. Personally I would get one and fit it unless your local arb fixer offers coffee and doughnuts to all customers👍 

[difflock]

£39.00 later.

No coffee or doughnuts, but a bit of crack.

And only left in at quitting time yesterday, and ready this afternoon.

Edited Friday at 17:43 by difflock

[spudulike]

Not bad service or price on that, a bummer that they don't do coffee and doughnuts though!

Hopefully it is all working and good now.

[difflock]

Thank you Spud, yes I ran 2 full fills through her when I got home and all quite faultless. but I need a polycarbonate visor for the forestry helmet, my lips were kept well pursed/sealed behind the mesh visor as I rotovated the dog shite (from our own dogs) among the grass, but that does NOT make it any more attractive.

P.s.

Quite horrified at the price trimmers/brushcutters of the FS200 class have risen to.

I suppose I have finally turned into my father!

P.P.S.

(i)John was adamant that E10 petrol was the culprit, for dissolving fuel lines and gumming up carbs.

(ii) They have stopped even looking at the DIY Chinese shite retailed by so many outlets.

(iii) I took a walk round the new Lidl store in Coleraine, and was gobsmacked at the array of Parkside tools and the prices, from memory

£50.00 for a metal cutting bandsaw.

£150.00 for a plasma cutter,

£80.00 for a gasless MIG welder.

Etc etc etc

Pure skip filling madness, and see item (ii) above.

Edited yesterday at 08:16 by difflock