Piston Skirt

Probably because You are doing things pretty correctly and not abusing the machinery, sir I’ve seen the tension / sagging problems mostly in the forestry industry where some guys simply can’t tell if the new chain is breaking in and then think the bar nuts have to get tightened. They do all those things from overtightening the chains (especially in winter), overtighten the bars up to the level where pins get ripped out through magnesium... and the list goes on.

It gets pretty hot. The crankshaft gets heat from the engine and the clutch (which does slip all the time). One of the outboard clutch benefits is also keeping that heat away from the crankcase (including oil tank). As for chain - it is quite a lot of force just to tension it right - try it with the bar & chain in vice and pull it to realistic tension. A hot chain sags, if you tension it and let it cool, the forces grow very seriously. That’s why chainsaw manufacturers recommend loosening the chain for storage.

The bits to fix sprocket assembly are gone on outboard - the clutch shoe holder acts as a master nut whereas on inboard clutch you have to leave around 5mm for a clip groove or a fixing nut thread. Also, because the chain is substantially closer to the crank bearing there is less levering force from it on the crank PTO part which permits using smaller shaft diameter. Also moving brake mechanism out of the crankcase allows making it narrower etc.etc... I know, it sounds “just a few milimeters” but engineers bother making expensive 2 piece cranks just to eliminate those couple milimeters.

Spot on. The PTO can be shortened a bit and even smaller diameter on an outboard clutch version. Anyway if you don’t want to see a painful smile on experienced chainsaw engineer’s face - avoid asking “inboard or outboard”. There is no clear answer - both types have their pros & cons and it’s a matter of compromises and quality of execution.

Nope. But they are likely to fail if the actual reason is still there. I’ve seen the metal strainers getting worn through and then letting metal particles go down to the pump. But it takes quite a long time in the forestry and total neglection.

Valid only for old 2511 without active idle correction. Otherwise most guys are “tuning by ear” and can’t understand why the saw is not reacting to L, or idles nice but does not accelerate properly...

MS170 and say MS 261 will differ in costs approximately 4 times. First of all MS170 consists of around 180-190 parts total while 261 will be somewhere between 350-400. Part number alone makes the costs very different. Then, of course, the assembly procedures which are needed to get all this together. Then there is the basic structure of the saw - MS170 has relatively simple steel conrod with pressed in roller cage bearings while MS 261 has a forged conrod with thermally treated ends and higher grade bearings in them. Both crankshafts are essentially different - MS170 has a regular pressed 3 piece crank while MS261 has a 2 piece crank where the PTO side is way harder to produce in 1 piece with the crank pin... Basically you can go through entire saw and most of the parts will differ like this, requiring additional operations and treatment which in turn consume energy and time which is not free :) And then there is QC which also consists of procedures. I might be wrong but MS170 and MS261 most likely are treated differently at that stage too...

All chassis (exc.1) designed after 2006 do. (In order of apprarance:) 310, 352, 590-621, 4510, 2511, 3510, 7310.

They invented it in ~2014 and introduced in 2017 in Japan. 3510 comes in both configurations.

Plug lead cap always was like that on Shindaiwa 446 and all subsequent units on that chassis. It’s 500ES and 501SX that have received the more durable plug cap to withstand regular spark plug changes (which obviously every professional does every 150hours :D) And that is a nut on a PTO end:

They all are still built to the exactly same standards - 3510 is partly a replacement for 15 year old 352 with far better features. As for pro line up it is not shrinking but expanding so from “few models left” it has already added 7310. More to come.

Has been so for a decade. Cs-500 was plastic-handled into CS-490. Now the 490 has a successor with a power bump-up in form of 4910. Where is the problem? In US market it is targeted at 271/450. How is it anything bad? As for the rest of the world the pro line-up is about to expand soon.

Well, the material IS mainly chrome yet obviously not the same as it was for some manufacturers. The coating is porous hence no need for honing to aid the better oil film properties. Other manufacturer ancient failures obviously have nothing to do with Yamabiko’s quality and technology as the latter one release nearly 3 million engines every year with either type of plating and none of the problems arise. Even the iron plating that previously was used for 360/361 wasn’t problematic, was it?

Echo is using it for decades - most likely you’ve seen it, just not from inside

Just as you’ve worded Nikasil (was a registered trademark IIRC), chrome isn’t the same in say a regular cylinder and Yamabiko cylinder. I won’t go deep in this but in the latter one you normally won’t even find regular honing marks. Both Yamaha and Yamabiko are still using it, actually, and they never stopped so there is no sort of “coming back” because there was never a “going away” - just a serious development over time. And yes, as i’ve mentioned the iron plating (not lining) is also something Yamabiko has developed in-house and it’s also superior to regular old-school chrome plating.

Nikasil is Mahle’s thing. Not all chrome platings are the same as well. The one used by Yamabiko is specific, used for quite many years and differs from those you will find in regular stuff. In 362 it replaced Yamabiko’s own patented iron plating which is also superior to the regular chrome plating. That one also has a long history. None of those have a bad reputation and none of them are “resurrected”

The nuts on WES model, just like the caps are a heritage from previous generation. Top handle had them changed. 360 is actually the oldest development of the 3 makers so no wonder it has some outdated things on it.

No. Last digit change on ECHO means minor update (like 2510-2511, this year’s trimmers & brushcutters 2620–>2621 etc.). If you look carefully - to enlarge filler holes 36x needs both tanks ant starter modified which is quite a major overhaul. That would change the model name into the recent/new 4-digit type.

360/361 -> 362 main difference is cylinder inner plating (now chrome).

It does characteristics wise. X series mark only tools for professional use that have one or more best in class features (i.e. power or weight or torque or ratio of them, or cutting performance etc. Or the combination of those). In other words - all X series are pro units but not all pro units are X.

I’ve never tried it with a Panther bar or chain but at least I know Stihl’s pitch is slightly off 1/4”. You can hear it when you first put on 2500 but later the sprocket wears in and the noise decreases. Anyway, my point (and that video too) is pruning - for average branches there’s barelly any difference. As for battery usage there is also a lot of saving if you dont push it into the cut - the motor control has an adaptive battery saving function and you can easily save 10-20% of energy without notably sacrificing cutting speed. Just feel the sweet spot with using the least effort.

2500 has slightly more torque but at lower revs and does not have a clutch. Therefore it has to be controlled differenty and for some cutting styles it may not work. Maximum cutting speed and control (“forgiveness” or “balls”) are different parameters. Also what most of the tests do not show is cutting speeds at different thicknesses (hence what you say in your post). At the jobs for which both the 25cc saws are made (pruning) they will work like in the video. BTW, does your 2500T come with .043 Sugihara chain/bar set? Asking for a friend

Well, stock vs stock 2500/2511 is in the beginning of the video:

Try unclipping it single-handedly. The point of the QuickDraw hook is it’s shape, allowing the action on virtually all belt hooks, not the fact that there is separate place for lanyard. Scroll to 4:00 in following video:

I spent 15 years working for Metabo distributor. Can’t advise objectively as I’m biased even after switching jobs