Chainsaws

Nearly everything you need to know to understand, run and maintain your saw

Everyone with a woodburner needs a saw to ring up logs, all too often people buy cheap Chinese saws which don’t last. Worryingly, some of these imported saws can be dangerous with questionable compliance to standards. For an infrequent cutter a Makita LXT battery saw will get the job done with minimal maintenance, but if you cut more often you may need more power and a 50 – 70cc petrol saw a more desirable option.

  1. Saws I like and use
  2. Fuel Aspen Vs mixing – whats best for your saw?
  3. Chains Main types
  4. Chains Identification and replacement
  5. Chains Sharpening
  6. Bars Sizing
  7. Bars Oiling
  8. Bars Cleaning
  9. Maintenance WIP

Starting with safety, here’s what I use and reccomend:

  1. Forestry helmet, with ear muffler and flip up visor
  2. Trousers, type A front protection will do, whilst type C offer all round.
  3. Gloves, left hand additional protection is OK providing the right hand saw foot plate protects from chain failure. The yellow Oregon have gloves protection in both hands
  4. Boots or strong leather shoes with steel toe caps
  5. Sleeves provide protection for fore arms
  6. Safety glasses

Saws: here are some great saws I really like:

Dolmar 420 SC or Makita 4300 – £350

A well made, reliable pro build 42cc saw Dolmar is now owned by Makita and the 4300 series is similar. Used with a 13″ or 15″ bar it should fly.

50cc – Husqvarna 346 – 629 Euros

Although replaced by the 550 MkII, the Husqvarna 346xp is one of the best 50cc saws ever made and highly desirable. High revving and cuts well with a 15″, I prefer the Sugi Hara bar as balance improves a fraction as well as being extremely durable. If you find one at a good price, buy it.

70cc – Husqvarna 365 X-Torq – £599

Now were talking! Perfect with a 20” bar and will run a 24″ comfortably, Husqvarna state 28″ max, but I’d say only with a skip chain. It’s a bargain for a robust semi pro saw. 70.7cc of raw power cuts 18” oak with ease. Can be upgraded to 372 performance with an easy mod! May be a tad heavy if used all day but a Sugi Hara pro-lite or other light weight bar bar helps.

90/95cc – Husqvarna 390/395 £1000/£1200

The 88cc 390xp is good but the 95cc 395xp is one of the best saws for big firewood, felling and forestry work which cuts anything with ease, 390 is probably best on 28” b&c whilst a 395 takes up to 42” & both port very well. If you cut a lot, you’ll finish the job sooner. The 395 with it’s outboard clutch and albility to run fairly long bars makes it a good saw for milling. Yes, I’d love either of these two legendary saws, but don’t have enough big wood to justify it.

The latest saws feature new technology usually to improve power. I’m no fan of this, preferring simpler ‘old school’ designs. The Husqvarna 3xx series is the epitome of good solid design, being relatively easy to maintain and repair. Its worth noting that Husqvarnas 346, 355, 357, 365, 372, 390, 395 & 3120 are all highly desirable and some of the best saws ever made.

No Stihl? Sorry but I dont like them, awkward flippy caps that leak or break, EZ chain adjuster never gets the tension right and ergo start I wish I never had are all gimmicks best avoided. I’m not sure what to make of the new fuel injected saws, they cut well but for how long? However their pro saws: MS 241, 260, 461, 660 and 880 remain some of their best.

Echo saws the 620 is excellent but not used them much they are very well made and come with a very good quality bar.

Fuel: good fuel is essential for you and your saw

Due to improvements in oil a 50:1 mix is now the norm, in fact someone told me they run their saws at 100:1 using Amsol oil. The ratio is now higher because modern oil is so much better quality. Whats needed is a good quality semi or fully synthetic oil for mixing. Using more oil weakens the overall mixture which could result in engine wear and sieze.
Petrol has changed for the worse, it contains ethanol which absorbs water and breaks down with age. Using fuel mix older than about 4 weeks may damage a two stroke engine resulting in expensive repairs.

The best solution for you and your saw is synthetic alkylate petrol such as Aspen or Husqvarna Power 2 (Aspen re-branded). It’s pre-mixed at 50:1 and remains stable for about 2 years.
Whilst Aspen may appear expensive, with long term use it saves. Engines last longer as the mix is always correct, it burns very cleanly preventing build up of harmful carbon deposits, its not aggressive to fuel system rubber pipes and seals which last longer and most importantly it protects your health as the exhaust is much cleaner than petrol mix fumes. Find out more about Aspen

I have used Aspen for over 8 years now with no absolutely no problems

If you mix your own 2 stroke fuel – do this:
Petrol – use 95, 97 or 98 octane higher octane is better it has less ethanol
Don’t use E fuels such as E10 and E95 they contain more ethanol.
Use a semi or better, a fully synthetic oil such as: Stihl HP Super / HP Ultra or HusqvarnaXP
At 13,500 revs your engine needs the very best !

Mix 5 litres of fresh fuel to 100ml oil = 50:1 ratio. Using too much oil is no substitute for low quality oil, which weakens the fuel/air mix
Agitate the fuel before re-filling to prevent separation.
If the fuel is older than 4 weeks put it in your mower tank & mix up some more with fresh fuel.
Don’t leave petrol mix in your saw – run it out or tip in your mower tank.

Chains – Main types:

  1. Standard chain with alternate left/right cutters.
  2. Semi skip chain it has two thirds of the cutters of a standard chain. It is possible to make one of these by grinding flat every third alternate left/right cutter.
  3. A skip chain or ‘fully compensated chain has half the cutters of the standard chain as every other link is missed.
  4. Semi chisel has a less agressive cut and keeps its edge, slightly easier to hand sharpen.
  5. Full chisel cuts faster but is more aggressive & prone to kickback making semi chisel more popular for non pro use.

Consider semi skip chain with bars of 24” or above that, a full skip chain is desirable because it places less load on the saw & also assists with chip clearance over a longer cutting span.

Chains – identify your chain to obtain the correct replacement:

To obtain the correct chain, you need four things:

  1. The number of drive links
  2. The gauge of the chain – this is the width of the drive link .043″ .050” .058” or .063”)
  3. The pitch – ⅜th low pro, 0.325”, ⅜th or 0.404”
  4. Then browse to Chain Saw Bars to order!

These numbers should be stamped into the side of your bar like this:

So in the above example, we have a the bar length of 45cm / 18” the gauge is 1.6mm or 0.063”, the pitch is 0.325” with 74 drive links shown along with the part number for the bar which is handy.

I use Oregon LPX, LGX or Stihl RS, Stihl may be slightly better but at a premium price. Both LPX or LGX are very good – LGX is a slight improvement in cutting over LPX but LPX keeps its edge longer.

Bargain chains? it’s usually false economy. They look good on the shelf but often dont hold their edge in use. Buy your bars and chains from Rob Dyers at Chainsawbars you get good prices and quality. There is also a lot of useful advice on the site as well.

There is a number on the drive link (DL) and a number on the cutter to help identify your chain using the table below:

Cutter number Pitch File Drive link number Gauge
1 ¼” (0.25″) 4.0mm 1 1.1mm / 0.043”
2 0.325” 4.8mm 3 1.3mm / 0.050”
3 ⅜” (0.375″) 5.5mm 5 1.5mm / 0.058”
4 0.404” 5.5mm 6 1.6mm / 0.063”
6 3/8th low pro – picco 4.0mm

No 1 & 6 – ¼” & lo pro generally used on small – up to 40cc saws
No 2 – 0.325″ is a stronger chain generally used for 40-60cc saws.
No 3 – 3/8″ is broader & stronger, its easy to sharpen & generally used on 60 – 95cc saws.
No 4 – 0.404″ is for large 100cc plus saws running 30” or longer bars, 3/8″ is now replacing it on all but the largest as I suspect 3/8″ has improved strength wise over the years.

Types of cutter – the main two are semi chisel or full chisel which cuts faster but more aggressive & prone to kickback. Whilst semi chisel doesn’t cut quite quiet as fast, it’s easier to hand sharpen.

Further chain info from Oregon

Chains – Sharpening
A sharp chain is essential for efficient safe cutting, particularly when using longer bars it reduces engine load. I hand sharpen my chains & find the ‘Vallorbe’ brand Swiss files are very good, make sure your file is sharp.

Dont wait until your chain is blunt – little & often keeps a good edge. I don’t use a grinder, they remove too much from the cutter & can cause inballance sending the saw off line when cutting.

I use a Husqvarna filing gauge which has a hole the same size as the correct file, so you can check you have the right file for your chain.

Check the rakers – the rakers are set in front of the cutter to ensure correct depth of cut. If the rakers are too high your chain wont cut. I set mine by eye looking along the bar from the front, probably not the best method it works for me, but it’s best to use a gauge. So check your chain after each use & sharpen if necessary.

Periodically I send my chains for a professional inspection & re-grind including rakers to FR Jones they come back factory sharp like brand new, with the rakers set at correct height.

Bars – sizing
To select the correct bar length I use the formulaes:

  1. Engine cc divide by 3 = maximum bar length in inches
  2. Engine cc divide by 4 = minimum bar length in inches

This a good guide, I find shorter bars cut better for example my 71.7cc 365 runs a 20” bar well with lots of power in the cut.

Often ‘entry level’ saws are supplied with bars too long, slowing in the cut. For example 18″ is too long for a 43cc saw. A 13″ or 15″ is a better choice.

A short bar provides faster cutting with less load on the engine. Whilst in the cut it will be less likely to ‘bog down’ theres also less teeth to sharpen afterwards.

Brands to look out for: Sugihara and Tsumura guide bars are probably the best, Husqvarna are the same as Oregon – a bit soft, Stihl are not bad but priced as so, Total Bars by Tsumura are good value – find them at chainsawbars.

Sugihara and Tsumura are extremely hard wearing & some have replaceable roller tips. A 20” ‘light pro’ is 450 grammes lighter than standard bar which makes a difference after a full days cutting. The Pro Laminated bars are cheaper than Stihl so worth considering. Anything that doesn’t last is just false economy.

Bars – Oil
Please don’t use old engine oil, it is carcinogenic and goes everywhere and not good for you or your bar and chain. Look for a specification of 150 (the Tackiness index) such as Total MST 150 is 13 euros here. Husqvarna 5L for 16 euros and Stihl 5L for 21 euros, both are good but at a premium price.

If you want to go bio consider Rapeseed oil or Stihl bio super some bio oils can gum up the clutch, theres lots of info on the net. However if you use Rapeseed oil you must keep your saw somewhere rodent free as they will gnaw through the tank to get to it.

Bars – Clean & dress
If I remove the bar, I clean the gunk that builds up around the mount & in the grooves. Check the oiler holes into the bar & supply gallery on the saw are clear, for good oil flow.

To clean the detritus out of the chain groove, I use a small screwdriver there is a special tool – but a small piece of rigid plastic or edge of a scraper will do so long as it fits the bar rail. If there is a grease hole for the roller tip, apply grease – a simple push gun is perfect.

Inspect the bar rail in good light & if it needs dressing then there is a tool but you can draw file if done with care. You tube has plenty. Take care as the burrs make evil splinters.

The side casing, clutch & sections around the bar mount get very gummed up so give them a good clean, check the bar oil holes clear. Check the spur drive or rim sprocket for wear before re-assembly.

If you remove the clutch drum – usually held in with a circlip for inboard clutches, clean out and check the bearing is good, apply light grease to the bearing taking care not to contaminate the drum with grease – avoid over greasing as the bearing will skate around the spindle and wear prematurely.

Other useful things to do or look out for

If I fit a new chain I soak it in oil before fitting, it makes a difference, if your oiler is adjustable then consider increasing oil flow for the first tankful of fuel, just to help the initial break in.

Maintenance – basic stuff:

As well as sharpening the chain, I periodically:

  1. Check chain tension and adjust if necessary but not too tight.
  2. Inspect the spark arresting screen (if fitted) in the exhuast box and clean if necessary.
  3. Check the air filter and clean or replace if necessary
  4. Clean out any gunk that builds up as it may affect cooling
  5. Check the drive sprocket/rim for wear, apply a small amount of grease to the clutch bearing – this only spins when saw is idling.
  6. If your bar has a roller tip grease hole, clean out and apply grease IAW manufacturers reccomendations. But dont over do it!

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