MS260 mysterious hole in cylinder - advice appreciated! :-)

[Bryapatch]

Hi guys,

 

Hoping for some advice about a mysterious (to me) hole in the cylinder of my 260, near the spark plug. Hopefully the pictures work and you can see what i mean:

 

 

 

So bit of background - bought the saw recently off a guy who put new crank seals, pot and piston in and carb.

 

First it ran fine, then it would stall when i let the throttle off and then wouldn't restart. I thought this might mean it was running rich, so i reset the carb to manufacturers settings, and got it idling ok. Then it ran fine all day on quite a big job, lots of logging so was working hard.

 

It still runs fine but afterwards cleaning it i noticed this hole. The spark plug was white aswell, which i know suggests running lean?

 

Anyone have any light to shed on this? Would like to retune it if nescessary before i do another job as i dont want to damage it through running lean.

 

Thanks a lot for any help, much appreciated.

 

Cheers

Alex

[Adamam]

It enables the saw to be worn around the neck on a chain.

 

Like Beastie Boys, but chainsaws instead of VW badges.

 

(It isn't; that would be dangerous. And uncomfortable.)

[predator]

myself would,nt worry about the casting hole etc but would set the saw a tad rich'er on the h screw so it fourstrokes a bit on the top end

[geoff]

myself would,nt worry about the casting hole etc but would set the saw a tad rich'er on the h screw so it fourstrokes a bit on the top end

 

Me too, good post.

[Bryapatch]

myself would,nt worry about the casting hole etc but would set the saw a tad rich'er on the h screw so it fourstrokes a bit on the top end

 

Ah right, so that hole is just a flaw from when it was made? So nothing to worry about?

 

Cool thats what i thought i should do with the H screw, thanks.

[Stubby]

Ah right, so that hole is just a flaw from when it was made? So nothing to worry about?

 

Cool thats what i thought i should do with the H screw, thanks.

 

I don't think its a flaw . Look at it . If its cast in there ( same finish as every were else ) then its meant to be there , If its got a shiny finish then some one has bored / drilled it them selves for what ever reason . Either way it wont affect the running of the saw . Its in a cooling fin and I suppose it could affect the cooling minutely but nothing to worry about .

[jomoco]

:biggrin:Optional decompression valve site.

 

Jomoco

[Stubby]

Optional decompression valve site.

 

Jomoco

 

Suggestion or a known fact ? Seems a little to close to spark plug but if you know thats what it is then thats what it is

[ArthurBottlesworth]

When assessing did audi a8

They unscrewed sparking plug and chunk head came with it

Fitted new head ( £10k)

Then did it again ......

Called in after they had done third one

Turned out to be hgh tension arcing and welding spark plug to head

Make sure ht not arcing

[SawTroll]

I assume that cylinder is a cheap aftermarket one?