adw

There is a difference between a copy and a counterfeit, this falls into the latter, perhaps if everybody here bombards him with personal messages he may get the message.

I still think you have an ignition unit problem as well, firing once and not starting are fairly common symptoms of a bad unit.

Just to clarify, there are two connections on the purge, the long one is the pressure side so back to tank, the short connection is suction so goes to the carb, purging will create an amount of pressure in the tank, I have never seen one blow fuel from the breather, you should be able to at least 3/4 fill the bulb, biggest issue with this generation of machines 135/140/435 is ignition unit failures.

They are 10 mm x1.0

I have tried this a few times with no success.

You are right Stubby, however leaving them on a fast idle for a few minutes can sometimes sort out the idle. Or there is the way we do not talk about, remove the throttle butterfly and use a 5/32 round file to increase the cutaway that is already there, do not remove too much though, about one stroke of the file and try the saw, it’s a bit of what I call a black art, but it does work., but make sure you try all the other suggestions, and do this as a last resort.

Any loss of compression for any reason results in poor, or no idle, sometimes a master reset works, but I would say compression issue.

You are absolutely correct about the way the pump works sir,I have to confess I have increased the angle with the grinder on some machines to increase oil flow, just need to be careful as it is timed to the pick up flat the other end.

I have never seen or heard this, my initial response is back to a dealer and plugged into CST and firmware update.

The 36/41 were replaced by the 136/141 and replaced by the 137/142, they were all basically the same saw but with improvements as they went on, most parts are interchangeable, the 36/41 had large crank seals housed between the cylinder and base, as the models evolved the seals became part of the bearing housing, so not interchangeable, biggest issue with this model was induction tube splitting, impulse seal splitting, crank seals blowing inside out, muffler coming loose and melting the top cover and in some cases melting through the oil tank.

On a slightly different tack, I ran a rebuilt 560xp today, I thought it was getting a bit smoky so opened the door to let it out, the old dear was going to phone the fire brigade as thought the shed was on fire,oops.

Just a note, never run the saw without the bar and chain fitted and the clutch still on, it can and will spin off on the over run, highly dangerous.

Very sweeping statement?

You must always de tension the chain as well as this will stop it coming away, re hot starting, cant remember if this is a mk1 or mk11, anyway if mark 1 hot start, no deco valve, plenty of purging to draw fresh, cool fuel through, lever to choke and straight back down to lock the part throttle, brake on and pull starter till she runs, same for the mk11 but has no deco valve.

Check the pump drive gear has not melted to the pump body, it can happen it the clutch spins off on the over run, and spins back on trapping the gear as no longer correctly aligned, this will force the gear into the pump and friction weld to it.

Miss use of the chain brake is the most common reason for brake bands breaking, continual knocking it on with the saw at high revs, I appreciate instructors tell you to engage the brake when moving, but not walloping it before the machine has returned to idle, removing the brake cover before disengaging the brake is very common, this will be why they cannot refit the cover as the band is now smaller than the drum, there is a tool to re engage it on 300 series saws, but on the 550/560 machines you have to part engage the cover and use the hand guard to engage it, or you could always remove the clutch and drum so as the cover will then readily fit back onto as to use the hand guard to engage it, the mark 11 550/560 machines now have a new style pump, sprocket and pump drive,this to improve sealing and function, so be careful ordering sprockets and pump gears as they are not compatible with the old set up, I have already seen the wrong sprocket fitted against a new style pump gear which jammed everything and destroyed the components.

And thirsty as hell.

Husqvarna K770 fuel filler cap will fit the fuel and oil filler cap of the 390, as for the auto start switch, this will be an issue, there is no diode in the 390 ignition unit so it will just restart when it springs back, and only stop if you hold it open, not a good safety issue.

Check the engine breather, if your getting pressure in the crankcase I’d could be faulty, if not Worn cylinder, piston and rings

Forgot about the TS400 wonder what happened with that, going back to the compensator carb Steve do you understand my thinking, not even sure if it had a compensator carb, but if it does and there is something blocking it the saw would run lean as there would be no atmospheric pressure on the flip side of the diagram, am I making any sense? I have seen it on power cutters where the gaskets have been fitted or after market parts fitted.

But leaning off when the filter is fitted is the complete opposite of what I would expect, surly we can rule out the filter and the choke? Impulse hose a good shout but surly it would improve slightly when the filter is attached?

I remember it, warranty? you will be lucky, where did it come from?

No fan of Stihl machines, however the ones I have seen have compensator carbs, so the metering side of the carb will not have a a hole to atmosphere in it, this is because there will be a channel via the air filter to the flip side of the diaphragm, so is this blocked or covered over?

Jonsered 2033, not seen one of those in twenty years or more.

Does it run really rich and cut out with the filter on, or lean off with the filter on? Does it restart easily once the filter is removed after stopping?