Carb101: A New Series

In just a couple of days time, on the first of August, DriveLink will be bringing you a new series, all about carburettors. Find out more after the jump...

Yep, there's an 7-part series all about chainsaw carburettors, and whilst the articles all relate to the carburettor purloined from a Stihl MS260, the basics should hold true for nearly all chainsaws. We'll take a look from the basics of what a carburettor does, through to how it does it and finally ending up with how to set it up and what to look for if the saw isn't running too smoothly.

So, that's Carb101 - a journey to the engine, starting on August 1st.

Stihl Quick Tension System...

Maintaining the correct chain tension is rather important - too loose and the chain may derail, too tight and the saw will effectively lose power. Many saws require the operator to carry around a combi-spanner to adjust the tension, but a number of smaller saws are available fitted with a quick tension system. In this article, we'll have a look at them and see how they compare after the jump...

I mentioned above a couple of issues regarding chain tension, but there's more; a chain that's too loose will also not cut as effectively as a correctly tensioned chain. Why? Because as the cutters come in to contact with the wood they sit back slightly, and that results in the cutting angles changing. A loose chain will also wear quicker, as well as increasing the wear on the guide bar. Fortunately you can easily recognise a loose chain - either because it's hanging down from the underside of the bar, or because it revolves around the bar when the engine is at tickover (with idle speed adjusted correctly).

A chain that's too tight will result in the chainsaw using up some of it's power to overcome the friction and that's what results in the lack of apparent power and unwillingness to rev freely. That increase in friction can lead to overheating too. It also puts the bearings of the nose sprocket and drive sprocket under undue stress.

So, convinced of the need to get the correct tension, the easiest and fastest method would seem appropriate; but different saws use different systems. The standard method, shown on the right, uses an adjuster screw that can be accessed through the side panel (although some saws have the adjuster screw at the front, facing forward, next to the guide bar - these are really awkward to use, especially with a combi-spanner). Before we can set the tension, those two nuts holding the panel in place must be loosened first as they're also clamping the bar in position.

Maintaining the tension in this manner requires the user to carry around a combi-spanner (with a flat end, not a Torx-head end). The operator first loosens off the two nuts, sets the tension using the flat screwdriver, and then tightens up the two nuts. Job done.

Nowadays, many users (particularly home-users) don't want the aggravation of having to have the combi-spanner to hand in order to adjust the chain, and manufacturers set about finding an even quicker way of correcting the chain tension with the least amount of fiddling about.

Enter stage left... the quick tension system. The example in the photo here is off of a Stihl MS250C, but it's similar to many other fast tensioners. The photo at the top of the post shows it with the side panel still fitted. You can see on that photo the large 'dial' on the side - this is not the tensioner, but it's a quick release for the side panel. The actual bit that the operator uses is on the top of the side panel - a small black wheel that links in to the cog fitted to the guide bar (that can be seen on the photo to the left).

To adjust this system, all you need do is flick the handle out of the quick release dial, back it off a fraction, then use the adjustment wheel to set the tension and tighten up on the side panel. It is quick and it doesn't require any tools. But is it any good?

Personally, I found it a bit awkward to get the right tension and it's not as finely adjustable as the good old screwdriver adjuster. Having said that, it does work, but I'm not sure I'd want one on a professional saw; for the home- / occasional- user however it's probably ideal. It also means that changing the guide bar is not quite as quick either, as that big cog is bolted to it and should be removed before swapping bars - the other thing that it means is that when it comes to your regular servicing and you turn the bar over to even out wear... you need to take the cog off and swap it over too.

So, for now at least, it's the old way of doing things that wins it for me; not just for setting the tension but also for ease of maintenance.

Call me an ambulance!...

Here in the UK, it's well known that the emergency services can be contacted by dialling 999 from a phone; that number came about way back in 1937. In 1991, a new number was proposed, one that could be used across all of Europe, and so the emergency number 112 was born. Fast forward to 2008 and it's now in use, but it seems that few people actually know about it. In fact, I have taught members of the police and fire brigade that didn't know about it! But, it does have some real advantages, find out more after the jump...

The idea about having a single telephone number that allowed a caller to contact the emergency services, irrespective of which country they were in, was a bold step. Language barriers not withstanding, the problem was that someone from the UK would neccessarily know what number to dial if they were in Spain (for example). The 112 telephone number solved that problem, and indeed these days many emergency call centres now speak several languages.

In the UK, emergency operator services are provided by BT, CWCW and Kingston Communication. A caller making a 999 or 112 call is connected to an emergency operator; these operators are not linked with the emergency services and their role is to select the required Emergency Authority Control Room and connect the caller to these operators.

The important thing for us is that whether we make the call using a fixed line, or a mobile phone, our location finds its way to the emergency services. If you dial from a fixed line, the registered address of the calling number is sent; but, if you call from a mobile phone things are a bit different as, by definition, you could be calling from anywhere.

In this case, the emergency services receive caller location information which is based on the network cell you are in when you make the call. Naturally, the accuracy of this system is heavily dependant upon the coverage area of the network cell. In essence the system calculates an area where it is 100% confident of you being, then a smaller area where it's 67% sure and finally it works out your probable pinpoint location.

This location information is needed; if you are incapacitated / unable to speak then the operators have a good idea where you may be; if you can't speak the language of the country you are in, then you can be reasonably sure that they'll know where you are calling from. In fact, silent callers are dealt with slightly differently due to the sheer number of hoax / false calls.

So, the next time you're out on location, make sure that you, and those around you, know about the 112 service - one day it might just save your life.

Get DriveLink on a Newsfeed...

You can now get the latest posts to the DriveLink site automatically, by using a newsreader. Now that doesn't mean you'll need to organise Fiona Bruce or Trevor McDonald to read the site for you, but you utilise an RSS reader to collect the information. Find out more after the jump...

Many websites now have an RSS newsfeed, and here on DriveLink, I thought it was about time to offer you the same. Posts that are put up on the site are automatically picked up by your computer, which means that you don't even need to visit this site to get all the latest on chainsaw maintenance issues.

I'm going out on a limb here, and reckoning that there's a high chance that you'll be using a Windows machine running Internet Explorer - we'll deal Mac's and Safari, or Firefox in a moment.

When you visit this site, you may notice that in Internet Explorer 7 there's a little orange RSS icon - clicking on this allows you to view the news feed and you should get the option to subscribe. Once you've subscribed, you just have to save it to your Favourites when prompted, and from then on hitting Ctrl-J will bring a list of your feeds up.

If you use a Macintosh with Safari then it's a bit different (but not much). When you come to this site (or any other with an RSS feed) using Safari you'll see a blue rectangle with "RSS" showing up in the address bar. Click on it, then check down the side for the "Actions" menu - select "Add Bookmark..." and away you go.

For those of you using the Firefox web browser, you'll see the orange RSS icon in the address bar, click on it and you'll get the option to subscribe.

Of course, if you're using 'odd' operating system - OS/2 Warp or BeOS, for example - you're on your own!

Makita DCS4301 Review: Conclusion.

So we've had a look around the saw and had a closer look at a few items on it; now it's time to draw some conclusion from using it. Find out more after the jump...

The Makita DCS4301 chainsaw is aimed at the home- or farm-user, and at this level I have to say it's perfect. Well, nearly perfect. It's lightweight, has some well thought out features (like the filler caps and easy start system) that will make ownership of the saw that little bit nicer.

There's a couple of minor things that could be improved and the main one is that chain catcher. Having a seperate catcher that is replacable without having to purchase a new side plate cover would be nice - although I'm wondering if the chain did come off whether it would wipe out the side plate housing anyway? Not something I wanted to try! The other thing was the refitting of the starter pulley, but I'm open to the suggestion that was just me!

The chain tension on this saw was just the standard 'loosen the bolts and tweak the adjuster screw'- rather than any quick-adjust system (although I believe that the saw can be bought with this option on it.

Access to all the bits that you need to get to regularly - air filter and spark plug, was simple and removal / refitting the air filter was quick and easy.

Overall then, I reckon for the target market this saw is an excellent buy - lightweight, powerful and easy to maintain. My thanks go to Makita for the loan of the DCS4301 chainsaw. Later on, we'll look at the professional DCS5001 chainsaw and see how it compares to others in this league.

NPTC: Things are changing...

The NPTC, who award many of the industry standard certificates of competence is undergoing a major review of the whole system. If you are interested in completing any of the chainsaw (CS-) units, or have an interest in the Forest Machine Operations units, read on after the jump...

Only yesterday (the 17th July 2008), NPTC put out a consultation document for Forest Machine Operations - you can find out more at http://www.nptc.org.uk/latest-news/detail.asp?dsid=305.

Perhaps of more interest to us, is looking at what is likely to happen to the CS units - the consultation period has actually finished for these units and it's looking like there will be a few changes in store. The one that peaked my curiosity was the CS30 (chainsaw maintenance and cross-cutting) was showing up as having a time-limit applied to the certification. It also looks like it's getting a re-write, so watch this space.

Other changes include the abolition of the CS33 large fell - this is probably a good move and (one assumes) will now be included as part of the CS32 medium fell assessment. Interestingly enough, the CS34 / CS35 (dealing with windblown trees) now only has CS31 small fell as a pre-requisite, whereas previously this had to be CS32.

It appears then that things are about to change, and that means that the training providers will have to sort out their provision to allow for the new changes. An interesting time in the industry and you can keep up to date with it by viewing the NPTC website - latest news - at http://www.nptc.org.uk/latest-news/.

Makita DCS4301 Review: Catch It If You Can.

Chain catchers. Vitally important in improving the safety of your chainsaw should something unexpected happen to the chain whilst you're using it. Different manufacturers do not create their chain catchers equally - even among their own offerings. So let's find out how Makita score on the DCS4301 after the jump...

Chain catchers are extremely simple devices and designed to take the energy out of the chain should it snap or derail. They are, in essence, consumable items and need to be easy to replace should something happen. Many of the home-user / farm-user level of saws have the chain catcher moulded in to the side plate, and this saw is no different. Of course, what it means is that should your chain demolish the chain catcher, you'll need to replace the complete side plate, rather than just the catcher itself.

The worst saw in this respect is my Husqvarna 350 - the chain catcher is actually moulded in to the main body of the saw! Not great.

Once you move in to the professional range of saws, things change - but at this level it's not unusual for the catcher to be integral with the side plate. Of course, you can help minimise the risks of something untoward happening to your saw by ensuring the tension is kept correct and ensuring the chain is being lubricated.

Makita DCS4301 Review: And To Cap It Off...

Something that really annoys me personally about the Stihl saws is the filler caps - they seemed to have engineered a technical solution to a problem that didn't really exist. Husqvarna and Makita have taken a more traditional approach to filler caps. OK, so it's not the most exciting of subjects, and I may have been a little unfair on Stihl, but let's take a look after the jump...

I should make it clear that the college where I work is a very heavy user of Stihl equipment, and boy does it take a battering out in the field with the students. There's no doubting the excellent build quality of the professional Stihl saws, but those filler caps...what were they thinking?!.

Stihl have manufactured a twist-on, twist-off cap that means that you don't need any tools to remove it and that's a big advantage over the traditional screw-on types. The screw-on caps tend to get tight during saw use and then become difficult to remove with just your fingers - with the Stihl caps, it's not an issue. On the downside, I've seen so many people think that they've fitted the cap (especially the oil cap) correctly, picked the saw up and then walked off to use the saw... en-route they stop, look down in disbelief as all the oil drains out of the tank as the cap was not on securely.

Makita (and Husqvarna) use screw-on caps - but the Makita version is actually really well thought out. It allows you to screw on the cap with your fingers, and undo it too - but if the cap is too tight, you can use the combi-spanner (screwdriver end) to loosen the cap. What you can't do is use the screwdriver to tighten the cap up (see the accompanying photo).

It's the small things that make ownership of anything a happy experience, or not (and I'm not hinting that the Stihl caps make ownership of their saws an unhappy one!). The Makita filler caps are well designed and simple to use.

Makita DCS4301 Review: Your Starter For Ten...

Before I carry on with this review, I must apologise for the delay in bringing it to you - it's been hectic here at DriveLink HQ and finding time to write it up has not been easy (what with having to finish the decorating!).

Anyway, without further ado... the loan DCS4301 was fitted with Makita's own version of an easy-start system. This uses a second spring to assist in turning the engine, and does indeed make it very easy to start - but are there any disadvantages? Find out more after the jump...

I first came across easy-start systems with the small Stihl chainsaws and was impressed - in fact, at Sparsholt College, after training several women on the chainsaws and seeing the difficulty they had when starting, the college bought one. It then got termed the "girly-saw" (very un-PC I know), but the interesting thing was that everyone who used it, liked it.

With that in mind, I was interested to see how Makita had implemented their recoil starter, which they call FeatherLight Start.

It works, and it works well and during a recent course I allowed a couple of students to use both this saw and the Stihl MS260. When it came to starting, the Makita won hands-down - "It's sooo easy!" was one comment.

Now this is all very well, but what happens when the starter cord wears down, becomes frayed and finally snaps? Just how easy is it to replace a cord on an easy-start system? Clearly, I was going to have to get in there with some molegrips and a big hammer take a closer look...

Removing the recoil starter housing was a simple task, requiring me to remove the four Torx-head screws. There's no fiddling around with the front-hand guard either (a la Stihl), it just lifts off. The housing holds the springs, pulley and cord and you don't need to worry about lifting the housing and everything pinging off in various directions! With standard starters, there's really only a couple of components - the main spring and the pulley holding the starter cord. This unit however, has an additional part that houses a second spring, and it's this spring that assists you in starting the saw.

So how does it actually work...? As you pull on the cord, this second spring gets tighter as it's acting against the engine. At some point the energy in this spring can overcome the friction of the piston in the cylinder and the release of the springs energy turns the engine over.

Anyway, back to replacing that cord. The starter housing has a black plastic piece that can be lifted out and helps with access to the starter pulley. To remove the tension from the cord you just need to pull a little cord out and then fit it in to a small notch in the pulley. The tension can now be released from the main spring and with this done the central screw can be removed from the starter assembly. Removing this screw allows the top plastic spring housing to be taken off - the spring within may still have a small amount of tension left in it, but it's negligible. Take a look at this spring as it has to fit back in correctly - the right way round and in to a couple of small notches. With the spring out, the main pulley holding the starter cord can simply be lifted out of the housing. The following images should give you the idea...

So, the removal was simple and certainly easier than I thought it might be.

And then I had to put it back together...

The manual would have you believe that you can just place the main pulley back in to the housing and turn a couple of times to engage the main spring with the underside of the pulley. I have to say that it didn't work for me and after inspecting the parts, I just couldn't see how my spring was going to catch the notch on the underside of my pulley! The problem was that the end of the spring was way off-centre and no amount of swearing cajoling was going to help. In the end I removed the spring pack (it just lifts out), engaged the spring with the underside of the pulley and put them both back in to the housing at the same time (see photo right) - a little fiddly, but it worked just fine. Happy that I had solved this particular issue, I then continued to put the rest of the starter assembly back together without a hitch.

So, all in all is the easy start system worth it? Definitely. Cord breakage, although it happens, is not something that should occur with alarming regularity - just keep the instruction manual and you'll be fine. It only needs a screwdriver to take it apart and the tools that come with the saw are more than adequate for the task.

Makita DCS4301 Review: Under The Covers

The air filter on the DCS4301 is hidden under the grey rear housing, which is easily removed by turning the large, black dial anti-clockwise a couple of turns. The dial itself is easy to grip and the cover is also secured by two plastic prongs along the front edge that must be positioned in to the main engine housing before tightening up, following removal to gain access to the components underneath. As for maintaining the filter itself, find out more after the jump...

Removing the top cover reveals the filter, access to the spark plug and the winter / summer setting. The air filter is held in by a wire clip, and what is nice is that the filter and the clip is shaped to make it a very simple affair to remove the filter quickly. There are no screws or nuts to undo, and although I find the twist-on, twist-off air filters (a la Husqvarna 350) easier, the wire clip really is no trouble and it does hold the filter on securely.

The spark plug is just forward of the air filter and the plug cap is moulded allowing you to get a good grip on it - useful when it comes to removing the plug. You do not need to remove the air filter to get the spark plug out (users of the Stihl MS260 would love that feature, although to be fair, if you've got a stubby combi-spanner you can get away with not removing the air filter when it comes to removing the plug).

The only other bit to play with under the top cover is the winter / summer setting - although it's doubtful that (in the UK at least) you'd ever need to take it off the summer setting. However, if you find yourself working in the cold winters of Scandanavia or similar, then it's just a matter of pulling the plastic cover up, turning it over and replacing it in the new position.

Other than these three things - filter, plug and winter / summer, there is nothing else for the user to touch; indeed the moulding doesn't even allow you a peek at the cylinder housing. Makita actually advise that you use a bottle brush from the side to clean out dirt lodged in the fins of the cylinder housing. All in all, it's very neat and certainly well-suited to the target home- / farm- users.

Next post... more on the DCS4301 chainsaw.

Makita DCS4301 Review: The Basics.

Makita have long been involved in producing quality tools for the construction industry, and truth be known, they've been producing chainsaws via their Dolmar company for several years too. But they've been overlooked by many who have preferred the two stalwarts of the forestry / arboriculture industry, namely Stihl and Husqvarna - but is that about to change as Makita start to gain a foothold in the market.Find out more after the jump...

Although I've been fortunate enough to have been given two loan saws from Makita for another project, I thought I'd take the opportunity to provide you with a review of them - the first (this review) is for the petrol-powered DCS4301 and a later review will cover the professional DCS5001 chainsaw.

So, you may have guessed that the DCS4301 saw is not aimed at professional users, but instead for the home-user, or farm-user.

The DCS4301 is a petrol-driven chainsaw, fitted with a 42cc engine producing 2.8hp. The 2-stroke engine uses a standard fuel:oil mixture of 50:1 (using Makita High Performance oil) - but you can run it at 100:1 using a special Makita oil. Interestingly enough, whereas the likes of Stihl recommend increasing the fuel:oil mix to 25:1 when using a non-Stihl branded oil, Makita recommend a slight increase from the 50:1 to 40:1. This, at least to me, is a lot more realistic and will prevent poor running performance and smokey engines.

The saw can be fitted with 3 guide bar lengths: 30cm, 35cm, and 40cm - all running a 0.325" pitch, 1.3mm gauge chain. The slightly thinner bar on these saws helps to increase the apparent power of the saw as it has to cut a thinner kerf than the more normal 1.5 / 1.6mm guide bars; you also have the option of two chains: 090 and 042. At the time of using the Makita saw, I only had a Stihl MS260 to compare it against and it's a little less powerful than this - but then the MS260 is a professional saw, the engine is 8cc larger and produces 3.2hp. Having said that, the Makita certainly did extremely well against it.

In fact, the Makita was used during a recent training course I delivered; one of the female students used it and said "It's really easy to start!" - an obvious reference to the Feather-Light Start fitted to this saw. I have to say the chainsaw performed very well and was a hit with the students. I actually used this saw when taking down a Robinia tree in my garden, putting a tool strop on the rear handle so that I could use it in the tree. Again, it performed admirably - it's lightweight, and combined with that 2.8hp engine had no trouble in cutting timber. Clearly it's not designed for the sort of knocks that professional use would subject the saw to, but it just shows how capable this saw is.

Maintaining a chainsaw can make a big difference to the ease of ownership - especially if you are non-professional user. The saw user only gets limited access around the saw, but what you can get to is a simple matter of removing a cover. The top cover can be removed to gain access to the air filter, the summer / winter setting and the spark plug.

The chain adjustment is either by the good old-fashioned tension screw (and it's good to see it positioned through the side plate, rather than right next to the spiked bumpers), or the quick-adjust system (not fitted to my loan saw).

Over the next couple of posts we'll take a slightly more in-depth look at the DCS4301 saw, but I hope this has given you a quick taster of this chainsaw.

EasyStart Systems...

Most of the major chainsaw manufacturers now offer an EasyStart system, designed to make using the recoil starter much easier to use when starting the saw. Stihl have their ErgoStart™ system and Makita have their Featherlight-Start™ system. These are often found on saws dedicated for home-users and 'light-use' saws, with the professional models making do with decompression switches instead. Find out more about these systems after the jump...

When teaching chainsaw maintenance and crosscutting I've found that many women have difficulty in starting chainsaws; for that reason we purchased a Stihl MS250C which is fitted with an ErgoStart recoil starter.

This uses a some trickery with smoke and mirrors springs to assist the user when starting the saw; and I have to say that it really works. The saw is so simple to start that a child could start it - although I'm not too sure why you'd want a kid to start a chainsaw, but you get the point. In fact, before we broke it when out on a felling course, this was a firm favourite amongst all the students (and I often used it for demonstrations).

As well as Stihl, Makita also offer their Feather-Light Start system that is very similar to Stihl's ErgoStart and is equally effective in making the chainsaw that much easier to get going.

So, are there any disadvantages? With the Stihl saws, there is a noticeable increase in the size of the recoil starter housing, which is just not apparent on the Makita system. The maintenance of the recoil starter is a little bit more awkward with these easy-start systems, but it's not too taxing.

The only real issue is that these systems do not seem to have found their way on to the professional saws - these tend to utilise decompression valves instead. However, for non-professional users or those using a saw only intermittently, choosing a saw with an easy start does improve the ease of ownership and they're well worth checking out.