SawTroll

Of course, but not nearly as badly as engine oil (or pure rapseed oil). Bar oil has a tackifier in it, that helps it stay in place longer/better.

Not that I have notised - and the bar oil isn't getting into the engine, unless the case gasket is leaking of course.

I would also do it in an emergency - but not on purpose..

Veg oil can do that eventually, if the saw is left sitting without preperation for a long time - but it won't do it on a saw that is used weekly, or even monthly. It will also "glue" the the chain to the bar, and the nose sprocket to the bar body. Veg oil is very nice to use though, so I won't stop using it. It is best to run one tank of regular bar oil trough the saw before storage - that should keep those issues away! Don't ask me how I learned this.

As long as you stay within mounts that have the same tail size code in the Oregon system (D in this case), the oil holes are likely to add up. The adjuster holes will some times have to be adjusted though.

I suggest you take those flanges (on the 123 bolts) down to 12.1mm (or was it 12.3? - measure the actual bar for best fit) to fit a a Stihl 3003/D025 bar. 9mm to 12mm adaptors are common, but I don't know of any 10 to 12 ones. You could make one simple ring adaptor for each bar bolt yourself though, out of a suitable metal tubing.

As it looks in the IPL, the bar bolts on that saw should be easy to reduce in size to take bars with a smaller slot than 14mm - but how much smaller is impossible to judge by that illustration....

Oopps - an adaptor would of course work the other way - you would have to grind the slot in the bar wider!

Your bar mount (D033) is a "D" size tail in the Oregon system, so it sounds like what you need is an adaptor that allows you to use either a 12mm D025 (Stihl 3003) 25" called bar, or a 9mm large Husky mount (D009) 24" called bar. Both are availiable in 84dl .063 - but the D009 one likely will have to be ordered. The oiler holes usually fit between the different "D" mount bars - not really sure in this case though.

The inside of your head is the most important safety feature. A firm grip with both hands help a lot as well. If you are totally new to chainsaws, the Stihl RM3 chain may be the right one to start with. It is semi-chisel, and "green", without making it really bad for regular cross-cutting. About the same is the case with Oregon BPX, but that one only is availiable in .325. BPX is closer to the borderline between green and yellow though. Just remember that no saw chain really is safe!

It more or less has to have something to do With the clutch or clutch bearing, if the bar and chain is OK, and the drive sprocket serviceable.

Most metal saw cases (including that one) are magnesium, not aluminum. Is that a factor here?

That one only kicks in when the operators wrist is hit by the brake handle, and it doesn't totally lock the clutch like modern chain brakes. No inertia activation like modern brakes either. Your attitude towards "green" chain is fine if you are not an experienced chainsaw operator. If you avoid hitting anything with the top halv of the bar tip you don't get any kickbacks anyway though. My 1970 Jonsereds Raket 621 doesn't have a brake - but I always used "yellow" chain on it, without a single kickback in many years of use. My point is that operator awareness is much more important than the "color" of the chain.

Likely true - just don't read too much into (or out of) the results without knowing the reliability of them.

How does he know that dyno is calibrated correctly?

Interesting - I was really referring to the situation in North America. If the brand had some brand recognition worth exploiting somewhere, Blount may well have kept the brand "artificially alive" at those markets?

Doesn't even look like it could be high quality - so it is hard to believe it actually is. Echo saws mainly are sold because they are cheap, not because they are good or high quality....

The 64dl 3/8 bars are "called" 18" bars, but you are right it really is a 17" bar. The 73 on your drive links tells that it is a .058 gauge Oregon chain, and nothing else. The dl count never is marked on the chain, you have to count. The only "green" Oregon 73 chain I know of is the 73V (vanguard - see comment in earlier post). Btw, if you want to measure a bar correctly, the measure you should take is from the front of the saw case, to the top of a cutter at the tip of the bar. That is how it is defined, but the funny thing is that the result may vary with the saw you put the bar on, and the size of the drive sprocket.

The MS261 is too heavy, bulky and clumsy to handle for a 50cc saw. The 550xp is much better in all those regards, as is the (now dicontiued) 346xp. The MS362 suffers from the same in the 60cc class - but the ol' MS361 surely didn't!

The 72dl (not 73) .325 bars are called 18" bars, but actually is shorter, as you noted. Stihl chain with that dl count will have to be special ordered unless the dealer makes the loops himself from a roll. However, in .325 you don't have to og to Stihl to find good "green" chain. The Oregon BPX semi-chisel chain is "green", and should be easy to get in 72dl at any Husky or Jonsered dealer (and many other dealers). I would prefere this chain to the RM3.

Good quality means OEM if the cylinder needs to be changed. Often it is possible to save it, and just change the piston though. If that is the case, a Meteor piston will be fine.

The 266 has an outboard clutch, not an inboard like the 064. Btw, the 266SG has heated handles - if they still work....

That's true - false sequrity. Cantdog is one of the true experts regarding these ol' Jonsereds saws.

20" is a long bar on that saw, but it will do it. Make sure the dl count of chain match with the dl count of the bar. K095 20" bars can be 78, 80 or 81dl, depending on when they were made and who made them. The 81dl ones are closest to true 20" bars.

So called "wire edges" is a result of wear, and really should have been filed away as soon as they appeared. You may still be able to save the bar by removing them (be careful not to break them off) - it depends on how bad the wear is. At the same time, make sure the rails a level. If you still have room for the drive tangs in the groove between the rails, the bar may be sevicable - unless the the groove is widened to much sideways, so the chain can "lean over" (typically results in crooked cutting). The Oregon selector show both .325 and 3/8" for the 49SP when I look - but it may vary with the marked you chose when entering their site (avoid using the US selector). Try the Canadian version if you don't find what you want elsewhere.... As far as I know, the only decent "green" 3/8" chain out there are Stihl RS3 and RM3. The Oregon Vanguard cuts very good when New (it is chisel chain), but keeping the rakers set right as the teeth are filed back is a challenge (haven't tried myself, going by what others have said here).