spudulike

I would surmise that if an accident were to occur, that the HSE would investigate training, safe working practice and equipment maintenance rather than looking to see if the machine may be modified and they would probably not have any ideas on how a chainsaw could be modified. I am out of the game now but using a modified saw is very much up to the owner.

Sorry, I was just going on your description above

Saws hanging on to their revs after snapping the throttle shut can be a sign of an air leak being present. Did the dealer give you the readout from the CST (customer service tool) test? The H&L carb settings from this document can often give an indication if there is an air leak.

Interesting diagnosis..."blow by", not a term often used!! It usually kills idle and causes puffs of fuel vapour out of the inlet manifold if you grab the throttle!! Anyway, if you have manually closed the carb throttle linkage and it still does this holding on to revs thing, it sounds like an air leak to me so looks like a full pressure and vacuum check is needed to me. It is possible the manifold to cylinder union is leaking or a seal has gone. I believe there was an issue with this saw model having crank bearings spinning in their seat...ADW will come around soon and add a bit of extra to my diagnosis.

Why not phone Barrie (Gardenkit), he runs a business down near Exeter and is one guy I do trust to give you good advice. Not sure he spends much time on here now! A PM may do it.

Great for a bit of detailing under the car bonnet if you like running a clean motor.

The 460 is a solid machine so no underlying issues in its build. I guess if I had one on the bench and had tried different bar, chain and sprocket combinations...USING OEM PARTS, I would get the verniers out and measure the distance from the sprocket to a fixed datum such as the first bar stud and rotate the rim taking measurements to see if there were any changes. You could then rotate the crank and see if you get any movement.....this is extremely rare but have seen twisted cranks on two machines - it looks pretty weird as the crank centre sort of wobbles as the crank is rotated. Is the crank genuine OEM Stihl? Do you know the machines history? I take it your sprocket, bearing and rim are OEM? I have seen all sorts and some aftermarket stuff is pretty poor TBH!

Great workshop tool, you can power an airline for cleaning, rattle gun/impact driver, tyre pump, staple gun, nail gun etc. Anyone in arb should own one to clean their tools. I started with a no tank compressor so it was pumping against the airline and you had to pulse the trigger, the next one had a 15L tank but the brushes went, the last one cost £45, had a brushless motor and 24L tank and has been perfect...noisy but perfect. They are great tools and have converted many, bored many others about how good they are.

It looks genuine to me but be aware that it is the 45cc version and not the 50cc second edition Silverside one. When buying secondhand from an unknown source, make sure the top end is original as cheap Chinese won't cut the mustard!! BTW - the grey clips were on the 50cc version as standard, orange on the 45cc.

Glad it worked out for you. I have been through this process many times and it works fine if you make sure you also do the full inspection, tests and carb refurb/setup afterwards.

What saw is it? The early MS261s and MS362s didn't have the best cranks and knocked the bearings and sprockets out regularly. Strange it wasn't the chain, most times I see this symptom, it is the chain.

most of the time it is just uneven wear in the chain that causes the symptoms you have.

That's the orchestral pianist career over

Shame they can't spell!!!

Thanks for letting us know. Glad it is sorted.

Have you cleaned the air filter and both sides? I had a customer complaining about his 2511 not revving out well and told him to use a bit of oil based fluid on the air filter and blow it out with an air line......it sorted it. These Echos do go out of tune and the uninitiated can make them worse, especially if they don't try them out in wood. I normally put the saw back to factory settings, tweak it from there if not stable and then cut some wood with it, just to make sure.

Did you ever check the fuel line as it could be opening up a split in certain positions. It is where it pushes through the tank wall? You can check the kill wire from the kill switch through to the coil, it may be earthing on the metal saw body but would need a chaffed wire and bare metal to do this.

Of course, nothing else sounds or feels quite like it!

Not over Mr Stubby....the 346XP is the best saw I have used and sounds soooooo good! Finding a good one though is like searching for the Holy Grail.

Yup, that inlet manifold is a bit of a sod when doing a pressure/vac test.

Why didn't you use the Mityvac for both pressure and vacuum? That is the reason most use them

My pressure and vac check is pump to....15 InHg, wobble the crank to and fro and check for leakage - if the reading stays solid and doesn't stop dropping, release the vacuum, pump up to 10 psi, wobble the crank to and fro and see if it drops. If you get a leak, you then investigate. I personally don't create a vacuum or pressure and then hold it for 5 minutes and mostly found if there was an issue, it would show up pretty quickly. On what you should check to stop it going pop again...most saws that passed through my workshop for rebuild/port/ full service etc were checked in regards to stopping it seizing : - 1) Compression 2) Vaccum and Pessure leaks. If the decomp leaks, I reground the seating and sealed with a little grease. Make sure you are also testing the inlet manifold and impulse line when doing the test! 3) Fuel filter....almost definitely worth replacing 4) Carb - strip, check diaphragms and metering arm height, check gauze strainer, clean and rebuild. MS460s tend to build up wood chip behind the metering diaphragm. 5) Tach tune to around 12,500-13,000rpm - make sure the engine is stable when flat out and not fluctuating. If you do this, it is pretty certain that your saw will last. The pressure/vac check is the solid foundation and the tach tune sets the saws maximum revs so the machine shouldn't fail again. The 460 is a pretty solid machine - I did find that I often had to pull the limit cap off the H carb screw as this model often over revs once they are loosened up. Others may have their opinion but this is what I did and it was a pretty reliable method for me.

Good to see it running again. I guess it was a new piston that did the trick and time will tell how reliable the repair was but hopefully it will last for a decent time. I would guess the workshops wouldn't touch it due to you not wanting the cylinder replaced and understand that if they are main dealers for Stihl, their business is to return a saw back to standard condition. Unfortunately, this often writes off a saw as a non economical repair and as I said, I have salvaged hundreds of saws back to good working condition that will last for many years. Yours looked fairly bad but it should last with a little luck and you have learn't a fair bit in the process.

It is alright, I will still be your friend

It won't need programming, why would it? Take it off, replace it correctly and it will work just as it used to. I guess you have stripped it down to some degree and cocked it up somehow and now it won't run. The full story of what you have done will help. If it isn't the carb that came from the machine, it WILL need programming!