spudulike

As Chris said, the only issue you have is a weak decompression valve popping out when you don't want it to. The resistance you are feeling is compression and probably isn't being helped if you lined the bore with oil from the rebuild. Personally........ 1) I would have tried to save the cylinder after ensuring it is the original part and not a £25 ebay POS. It is very possible the seller has swapped out the top end with a low cost option which if the case, is a real shame. Take a pic of the top and sides of the original and we will be able to tell. 2) I would have pressure and vac tested the saw after rebuilding it. 3) I would have serviced the carb...I am assuming the new one is a £25 special off eBay....I have found these to be a bit unstable on the idle, OK flat out but very sensitive on adjusting the H & L settings. 4) Finally I would have tach tuned the saw for around 12500rpm...........1000rpm below manufacturers. maximum. My skeptical mind is saying that the seller purchased a non runner, stuck a cheap top end on, did none of the good stuff listed 1-4 so missed the original fault that caused the issue and you purchased it and it went pop. You could get the saw going but the only aftermarket kits I would trust on a saw of this type is Meteor or Hyway. Anything else is a poor compromise unless OEM. A cheap top end will show it's heritage as soon as a 36" bar is stuck on this 660! METEOR Piston & Rings Fits STIHL 066, MS660 Chainsaw 54mm 1122 030 2005 WWW.EBAY.CO.UK Find many great new & used options and get the best deals for METEOR Piston & Rings Fits STIHL 066, MS660 Chainsaw 54mm 1122 030 2005 at the best online prices at eBay! Free delivery...

If the JB Weld fails (it probably wont) try an epoxy putty called Milliput, this will stick like the proverbial and drys to be rock hard - make sure the receiving surfaces are degreased with brake cleaner. Don't replace the carb, just stick a new carb kit in it or clean and service it....most carbs have pretty much nothing wrong with them.

Meteor or Hyway, the rest are a bit suspect. You may get away with salvaging the OEM top end and fitting a Meteor or Hyway piston as a lower cost option.

Two strokes are one of the simplest engines out there, the piston and cylinder are pretty simple once the timing and durations have been designed in. Two major moving parts - not like the four stroke with valves, springs, cam shaft, cam chain/belt/gear, lubrication pump, etc etc. The strato doesn't really make the engine more complex, you still have a cylinder, a piston, an inlet manifold, a carb.....they just look different. Fuel injection in to the crankcase does allow much more efficient control of the fuel input that the typical cylinder based inlet port can't and controlling the timing and duration can be electronically controlled to give more torque and power - try an old machine with reeds where the carb feeds fuel direct to the crankcase - more torque in most cases...... It is how Bimota went some 30 years ago but failed....an interesting story!

Just seen the vid - two air ports and one fuel air port (middle one). The air ones are for the top of the transfer air charge. I am sure that is what the fella is saying can't be bothered to watch it TBH!

Two strokes, of traditional design, are pretty dirty as they use fuel vapour to eject the exhaust gasses from the combustion chamber through a scavenging process and some of this fuel vapour is pushed out of the muffler during this process. The strato type saws do as mentioned earlier, the piston and inlet design allows the engine to load the very top of the transfer port with a charge of fresh air which is what pushes the exhaust out so vastly reducing the amount of unburnt fuel vapour in the exhaust. That is how they work - the air is metered by carb, inlet manifold design and the timing of the piston and cylinder.

Go easy with the pressure washer, it may blast the render off giving you a bigger problem!! A bucket of warm soapy water and a scrubbing brush would be my weapon of choice. Get your lead fella to accompany you on the apology and clean up, that should make sure your lads are kept in line.

God knows.....he knows everything. Us mere mortals can only guess!!

It is very possible that the cylinder can be salvaged and a new aftermarket (Meteor or Hyway) or an OEM piston can be fitted. It is the sort of work that made me very popular but am pretty much retired now. A dealer may frown at this suggestion but have done hundreds of saws like it and the process works if done correctly.

Fuels like Aspen, Husqvarna XP Power 2T Alkalyte and Motomix will not go off like a standard 2T oil and petrol mix will. That is why it is good for the infrequent users. Personally, I mix fuel up in a small lemonade bottle so I can fill the saws tank and no more. That suits my "bit of firewood", "garden pruning" or testing a saw which is my usual saw use. Your option is to perhaps use a 1 Litre mixing bottle or use one of the previously mentioned Alkalyte fuels.

I think you have solved your issue yourself. Once the oil is mixed with fuel, the fuel starts degrading the oil and if left long enough, it does nothing. Two months is far too long, two weeks is OK, and two days far better. You should only mix fuel you will use on the day and never leave a saw on the shelf with fuel in it not knowing when you will use it next. Lots on this site stating that time and time again. FYI...the Autotune actually does a fine job of protecting the engine. I have seen some with major air leaks survive just because the AT unit has seen the saw running lean and has increased the fuel in the fuel air mix to accommodate the extra air being drawn in to the engine. Unfortunately, the AT won't monitor cylinder temperature so in your case with 2 month old fuel, it wouldn't have seen any issue until it went pop. I am afraid that the dealer is probably correct in his assessment. BTW - you are not the only one who is unaware not to mix fuel months before use!

Yes, if the plating has gone....Nooooo to strong acid or alkali.....you are looking at smoothing the edges of the damage a little so the piston just contacts the high & good part of the bore.

I would say the areas are where the plating has been ripped off the bore. It is easy enough to tell - inspect it with a magnifying glass and see if they recess in to the bore or protrude out from the bore. Recess = ripped off plating Protrusions = transfer It is often difficult to tell from online pics but I think the plating has partially gone. The good news is the damage is BELOW the exhaust port so if the plating has failed ( I have seen this before), you can often LIGHTLY smooth the surround of the areas around each area of damage (you may already be there) and then just fit the new piston and "see how it goes". The engine can't see your dilemma, it doesn't sense your reticence in its looks, it just works on if the bore can support the piston and seal when it needs it....the top of the stroke. The worst that could happen is more plating may come off and mess up the piston. The best is that the bore settles and gives a few more years service. Give the exhaust port a re-bevel, check the area with a magnifying glass, inspect the bore for any other lifting of the plating and crack on. I have had this sort of thing before and shared these same conclusions with the customer. A new cylinder kit is damn expensive - fitting the piston, getting it running and putting a few hours on it is a better idea IMO.

The biggest drawback is that the Four-Stroke sounded like a super wet fart and not like an 80s Pro Am bike race.

It would help to know if the wood won't split as it is rock hard or spongy. Some Elm I have had has been like concrete so may be a good call from that point of view. I guess we won't find out!

OK......that's great, congratulations to you and the best of reasons rather than some of the other ones. Hope it all goes well.

I hope all is OK with you, the dry bit sounds like doctors orders and hope it is nothing of great consequence.

The oil manufacturer states a ratio and if you use that, it will work as intended so if the mix is new, the engine will be lubricated correctly. Personally....I tend to use a little more just for safety sake but that is my choice. The correct ratio is the ratio stated by the OIL manufacturer and not the possible manufacturer of the 1980s equipment you are using......50:1 was an impossible dream in those days. MS880 - do the clean up on the cylinder, new piston, pressure/vac check and then tach the machine conservatively.....all will be good but do check the oil pinion drive....it is a weak link in my experience!

Just from the sponge and difficult to split description, it has to be willow! It meets both of these from past experience.

That wouldn't happen as the correct perspective would be only from the side viewed. It would look flat from the side of the sheep and before anyone asks, I don't know why they avoided the drawn in bit....perhaps some tasty Sheep food to the left of the path.

Oh hell...here we go again, you had to ask........it is a personal choice...bit like marmite!!

They drove me mad. I did have one in the back garden and a thumping great big one in the neighbours front garden. The biggest issue is them getting through windows on the latch and inside cars. I had the car serviced and the poor fella pulled out the pollen filter and spent the next 15 mins vacuuming it out. I once hooked a bucket and a half of tree seeds out of both front wings. I hate the things but have since moved....the catkins and leaves are not much better either.....I hate these trees and have no solution apart from removal. The 4-8 weeks is cobblers, they drop them month after month and are one of the most annoying trees out there!

I resorted to sticking bluetooth trackers on my fathers walking sticks when he was in a care home as the residents kept pinching them and he had around 5 floating around the place....it really pissed me off. I never got to test them as Covid struck and he bowed out a few months later!

On the big saws, it is generally owners using 1/4 tank and sticking it on the shelf for three months and then dragging it out thinking.....I may get the fell out of that tank.....10 minutes later...seized saw. I did get a 880 in once.... lacking power...oiler wasn't working fully!

That is sooooooo true. Been there on many a job and if you priced it at a normal hourly rate then it would be eye wateringly expensive but.....if you are working for yourself or own the business AND have a death or glory never give in attitude (and that can be a pain believe me) then you can do what you want and I HATE to be defeated by a piece of inanimate metal!! I would rather stick in a few extra hours and fix the damn thing as long as the spare parts don't make it uneconomical!