Another 2-stroke query.

[peter]

Tail end of last season my circa 1980 Paige Setter strimmer decided that full throttle top speed was no longer the done thing. Open beyond half throttle and it died.

On the lightweight bench over winter I found that the foam make-up pad that passed for an air filter had broken down and half had vanished. So assuming this was the cause of the ills, too much air getting in I went on the hunt for a replacement. Ended up with a bit of "that Kohler stuff" from s local mower workshop, bit like a dishcloth an offcut for me to trim to fit.

No change, same issue, suggestions?

[robo]

what happened to the half that vanished, could it be in the carb

[Ricard with an H]

No change, same issue, suggestions?

Fuel filter need cleaning or replacing ?
Fuel pipes are known to deteriorate and cause problems.
Carb service kits (Gaskets and diaphragms) are about £7 and it's easy.

Your strimmer will run without an air-filter but not with one that is clogged with fuel-oil or grass.

Try emptying the fuel/oil mix, replace with neat petrol and pump it through with the little primer bulb. Give it few pulls to get neat petrol in and do a cleaning job. Obviously if it starts you need to stop it quickly.

The remains of your air filter are probably in the crank-case along with other detritus, why not lift the pot. If you haven't done this before it isn't difficult but you do have be methodical and careful in some areas, you may find 2mm of carbon that needs dealing with.

[Ricard with an H]

Another one that has sorted out one of my machines is the coil/magnet gap. Whe I stripped the 48 down the coil contacts were rusted and lots of dust and grass was settled and bedded-in. I did have a spark but sometime s I might not have so after I re-assembled the machine I tested it with to big a gap. Too big a gap and you wont get a spark though I couldn't re-create a dirty gap or to small gap.

Checking that gap and cleaning the contacts is an easy task and I figure part of the two-stroke black-art.

All my machines are now working though I can't be certain if any one thing fixed them.

After a de-coke the machines did behave differently, I had to re-set the idle and the 48 was a lot more responsive.

[Clive.]

I am not familiar with specifications with regarding moving the coil/ignition unit on small 2 strokes...however on some 1980s/90s 4 strokes the air gap between flywheel and the coils laminated metal legs has an effect on spark timing and thus was set with feeler gauge, easier said than done. One manufacturer supplied plastic strips for this setting. Thin card...was another way....

As ever perfect theory and manufacturers specs are good but then sometimes it has to be applied to older tired but still quite usable machines with perhaps slight wear adding to the setting fun..

Clive.

[Ricard with an H]

I did manage to get an exact air-gap distance for the coil/ magnet situation though if you look on You-tube at the numerous videos made by experts they universally use what they call a business card. I used a thin credit card.

[oldherbaceous]

My old two stroke Mantis tiller, that i was given, packed up this week.
I took it to my true gentleman mechanic, who took the coily thing of his mantis and put it on mine, just to get me up and running. Now that's what i call kindness, and very helpful as i'm trying to catch up all round.

[Ricard with an H]

Thats interesting, how did he know it was the coil ? I suppose it has to be either the plug or coil if you don't have a spark.

Just to get the record straight i'm not professing to be an expert, just sharing and gaining some experiences.

If the two bolts holding the coil in place come-loose the coil will be inexorably drawn to the magnet and close the air-gap. I have used blue threadlock on two of the three machines i've been fixing and servicing.

A kind gentleman indeed.

[oldherbaceous]

Evening Richard, he seems to be one of those blokes that as soon as you tell him the problem, he has a good idea what is causing it, even before he starts the job. He always wants to know the make and model though, so i suppose these have their their own particular faults, and he has learnt these over the years.

[FelixLeiter]

Tail end of last season my circa 1980 Paige Setter strimmer decided that full throttle top speed was no longer the done thing. Open beyond half throttle and it died.

More than likely the coil / condenser. The ignition is advancing at higher revs, by the sounds of it, because of reduced inductance. First, though, you could always tweak the carburettor settings.

[Ricard with an H]

Evening Richard, he seems to be one of those blokes that as soon as you tell him the problem, he has a good idea what is causing it,

A proper expert in my book, two strokes are simple machines though there are enough fault-variations to turn the whole issue into a nightmare.

My case is a good example, you could hardly describe me as a 'dumbkopf' when it comes to find my way around a two-stroke and yet even though I solved my problems I don't have a clue what those problems were.

Right now each machine starts on the first few pulls if not the first, when I started the other thread I had checked everything, I found no faults yet non of the machines would start. My right arm is still sore.

I proved the fuel.
I proved a spark.
All three carbs are fine.
The fuel filters were not blocked.

Black-magic ?

[oldherbaceous]

Afternoon Richard, well i think you were very brave stripping your machines down like that, and maybe your approach to doing everything is quite a good one, as it leaves no stone unturned.

Glad you got them running, and also hope your arm is feeling a little more like normal.

[Ricard with an H]

Afternoon Richard, well i think you were very brave stripping your machines down

I was a bit nervous with the smallest machine when it came to replacing the pistons and positioning the rings correctly. Replacing the spring clips that hold the gudgeon pin in place because everything is so small and if if you drop something into the crank-case you may never get it back and then there is the fear of breaking a part and not being able to source it. Living this far west I rely on the internet and haven't yet found a source of replacement for the ignition coil and each machine has a different type.

Having said that I have a warm workshop with a workbench at the right hight, good lighting and plenty of tools.

I noticed that quite a few machines with different names have an engine almost identical to the Kawasaki engine in the case of brushcutters/strimmers.

I've learnt a few things and gained helpful comments from contributors to this thread, the advice by Sally about leaving fuel in the machine rather than draining and running it dry as the manufacturers recommend in the case of Kawasaki, Stihl and Husqvarna is for me a preferred way to lay my machines in future. The only reason I can think of that my machines didn't start is that some sticky-stuff messed-up the carbs function and it eventually freed-off.

Peter is keeping quite, what's happening Peter ? Is that machine working yet ?

[robo]

my rotavator gave up this afternoon just when I have a full half plot to sort, the engine is fine (briggs and Stratton 4 stroke) its the chain drive that's broke and its inside a fully welded case there is no way in apart from cutting the welds fixing then re welding

[Ricard with an H]

Oh-hell, first thing I thought Robo. Chains are usually regarded as consumables so you would have though access should be easy.

Can't you tie a new chain to the old one and pull it through ?