adw

So, the 266 had a closed transfer port cylinder, and a windowed piston, the 61 had an open transfer port cylinder and a non windowed piston, you could fit the windowed piston in both 266 and 61, however you cannot fit a non windowed piston into a 266. So I have no idea what these different cylinders and pistons are about.

One for the 266, and one for the 61 with open transfers.

The only time I have seen that was with a Chinese cylinder and piston on a 357xp and it was the piston that wore not the Gudgeon pin.

Yes you will need to change the induction block, gaskets and screws, can’t think of any other reason it will not fit.

Seconded very good guy.

Another quality cylinder from China, unfortunately you get what you pay for, if your not happy with it send it back.

Pleasant is correct and I am fairly sure the warranty changed to one year.

Yes fit them back into the piston, the picture is a bit deceiving as to how distorted they are, the steel rings were always a bit odd, hence they changed to a cast ring piston.

Those are steel rings, will they not re twist? I confess I have never seen that before.

Oh that is interesting, it sounds like you have the later updated filter and filter housing, strange because I thought that did not come till much late, but was offered as an update kit.

Good to hear it is going well, perhaps your a convert, the yellow filter is 44 micron so there should be no issues with it, unfortunately it is no longer available and will sub to the orange frame, you could always update it to the screw down filter, same as the 550 mk 11.

2020 would likely make them late mark 1, so I would guess they have the orange frame air filter, so a very good clean , do your machine service, then bury the saw full bar length into a log to reset the carb which may have leaned off to compensate for a blocked filter, they should have most of the updates as they are late machines.

Auto tune is a very reliable system, however it can be its own worst enemy, auto tune will always try to keep the engine at full power, so if the air filter is part blocked it will lean the mixture to compensate, the orange frame air filter is 25 micro and even thought they look clean they can be blocked, and this in turn causes the carb to lean off, depending on the age of the saw there have been many updates, most to improve acceleration and hot restarting, idling is set via auto tune at 2750 rpm, the first thing you lose when there is any cylinder or piston wear is the idle, if these are mark 11 machines a pressure vac test must be done as they are quite prone to the crank seal behind the flywheel leaking. Hardened metering diaphragms have become an issue due to all the fuel issues we know very well, again depending on the age of the saws a firmware update would be a good idea, also to see the L circuit number, the numbers runs from 5 jet fully open to 150 jet fully closed, this figure can give an idea what may be going on, the fault codes given in cst are all based on these settings, base setting is around 70/80, as Steve said it is still a two stroke engine so can have all the usual two stroke issues, fuel system, engine condition etc.

No it could well be a leak which will get worse as the saw heats up, also if it’s an x torque machine check the induction boot is correctly aligned to the cylinder.

I would be a bit concerned that something has come from down below to cause that, maybe a bearing cage breaking up, before fitting a new cylinder I would at least pull the crank seals out to see the bearing cages.

Could be a few things from running too lean on the carb low circuit, to an air leak, to a blocked tank breather, to a part blocked fuel filter, if the saw has been left with fuel in it for a long length of time the metering diaphragm could have hardened.

Do not remember there being a Husqvarna 454rxt?

The bigger question is why are the shearing the key? as I see the only way it happens is if the flywheel has been removed and not sufficiently tightened when re fitted, or it has been miss aligned on the crankshaft and the nut tightened down.

I am well aware the taper holds the flywheel, however the chance of lining up the broken key in the keyway exactly is pretty slim, you will end up with the saw ripping your fingers out of there sockets.

Good luck with that!

I am pretty sure there is a difference in the flywheels between the 550xp mk1 and the 550xp mk 11, so be careful what you order.

The answer is no, plus if it’s a G then it has the generator magnets inside so needs to be a G flywheel if you want to continue with heated handles.

Bearings and seals will be no problem as they are still used on the K1270, pretty sure there will be an Oregon sprocket available for it or the 2100/2101/298, the crankcase gasket may be an issue but could always be made as was not very complicated.

Don’t how they got the brass neck!

It was basically a 2100 with a smaller cylinder and the 480fuel tank, mid 70s how long do you expect a manufacturer to carry spares for an old saw for? What sort of parts are you looking for?