What's on your bench today?

[felixthelogchopper]

Now I'm going for a bit of a stab at this Felix.

 

The bulb only brings up enough fuel to get the pressure up. After that the engine does the rest.

 

Is the plug getting wet after trying to start?

 

I would look into the diaphragm, in the carb. Or the impulse line,

 

I wouldn't get stuck on the hiss from the tank. It's only from pressure that is a good thing as it pressurises the tank pushing fuel up to carb.

 

Cheers Rich. I'll have a look at the plug when I go back to it. I was thinking fuel line but the hiss kept distracting me. It is forceful enough to spray a bit of fuel out after a few goes of getting it running with the bulb. I've done fuel lines no problem, but how involved is the diaphragm on the carb?

[Rich2484]

It staking the carb off and removing the covers. Stripping it down basically. Doesn't take hat long. But once its off make sure you clean it before taking it apart. A spray of wd40 and an airline helps, or a paint brush.

 

The hiss does sound forcefull. But a vent only works one way, it lets air in but to out. If the tank is holding pressure then that's ok.

[felixthelogchopper]

It staking the carb off and removing the covers. Stripping it down basically. Doesn't take hat long. But once its off make sure you clean it before taking it apart. A spray of wd40 and an airline helps, or a paint brush.

 

The hiss does sound forcefull. But a vent only works one way, it lets air in but to out. If the tank is holding pressure then that's ok.

 

OK mate, looks like I will have a go at doing my first 2 stroke carb if it isn't the fuel line. Cheers!

[Rich2484]

Get into trouble the help is on here bud.

[Joe Newton]

The pin is a gudgeon pin or wrist pin if in the US. it is held in place with circlips that can be little mothers to remove - just be damn sure when you fit the new piston that the circlips are in the groove in the piston otherwise the circlip will spring out and mash your cylinder.

 

You will also need to ensure the arrow is pointing toward your exhaust port and make sure the ring ends are in the same position as the original as I have known Chinese pistons to have arrows pointing in the wrong direction.

 

The lug - try and drill and pin it - JB won't hold it, I have pop rivited and pinned parts before but without seeing it......or by a pattern part if you can find one or secondhand unit.

 

As far as pistons go, in order of best first OEM (original equipment), Meteor, Episan, Golf, Chinese. With rings - OEM, Caber, Chinese....I have known Chinese rings to fail and to do severe damage.

 

I Guess I'll have to wait and see what they send me then, and hope for something other than oriental...

 

The circlips came out pretty easy with a pick, but they aren't the kind with tabs on them, so putting the new ones in (if the same) is going to be fun. A friend is lending me some circlip pliers, but without those little tabs I doubt they'd work.

 

Am I right in thinking that the openings in the piston rings must be facing the rear of the saw, air filter side, and not the exhaust side?

 

I think a light polish of the cylinder with an emery cloth would help, and I noticed an seemingly unnecessary bit of metal on the intake port. Would match porting it help efficiency?

 

Also pictured is the broken lug on the recoil cover, looks a bit too small to drill or weld.

[Dan Earp]

Since I've bought some aspen, i decided to buy a set of gasket diaphragm(cheers Garden-kit(barrie)for my ms260.

Now I've never done this or even taken out the carb before! And was planning on doing it over two nights.

On opening up the carb i found the diaphragms to be like new? Though ever so slightly sticky so decided to change the set. 30mins later it was back in after a blow out (and the rest of the saw) checked the spark plug colours and done👍 so now having a beer thinking i should stick to saws and not iPhones lol. Thanks also to GTR(rich) for some little pointers

Now just waiting on the aspen💪

[felixthelogchopper]

Get into trouble the help is on here bud.

 

Cheers mate, you may come to regret that offer.

[spudulike]

I Guess I'll have to wait and see what they send me then, and hope for something other than oriental...

 

The circlips came out pretty easy with a pick, but they aren't the kind with tabs on them, so putting the new ones in (if the same) is going to be fun. A friend is lending me some circlip pliers, but without those little tabs I doubt they'd work.

 

Am I right in thinking that the openings in the piston rings must be facing the rear of the saw, air filter side, and not the exhaust side?

 

I think a light polish of the cylinder with an emery cloth would help, and I noticed an seemingly unnecessary bit of metal on the intake port. Would match porting it help efficiency?

 

Also pictured is the broken lug on the recoil cover, looks a bit too small to drill or weld.

 

Firstly - for God sake - do NOT remove that tab, it makes sure the rings don't snag in the inlet port, removing it will cause bad bad damage to the rings and bore:blushing:

 

The openings of the rings can face forwards, backwards or both, on a saw of this age they generally run down both sides of the inlet port.

 

The circlips can be a pig to get back in, I generally push them in with decent quality long nose pliers - someone did say to push the circlip in to a thin tube and then push it out in to the piston - not tried this one out.

 

The lug, I think I would make a thicker lug and then pin it to the casing with steel pins and JB weld and then spray it - or just get a second hand cover:thumbup:

[Joe Newton]

Firstly - for God sake - do NOT remove that tab, it makes sure the rings don't snag in the inlet port, removing it will cause bad bad damage to the rings and bore:blushing:

 

:biggrin:This is why I ask you good folk first, was pretty sure it had to have a reason, or it'd have been a pretty obvious design flaw!

 

I've spend most of my evening practicing reinstalling the old piston and circlips on the kitchen table. I've got a pick with a notch in the end which seems to work, I'm now confident. My girlfriend isn't speaking to me, either.

 

I'll keep my eye out for a second hand cover. My tool collection is limited, and my experience more so.

 

Cheers very much for your help guys. I've really learned a lot about the guts of a saw from this. Its safe to say I've got the bug now .

 

I'll let you know when its back together how it runs!

[Ray1]

The circlips can be a pig to get back in

 

Wear some eye protection when your putting them back.