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Sunday, 19 November 2017

Huztl Farmertec 036 MS360 chainsaw kit review

The Huztl 036 after 10 hours hard work (with home-shortened bar)
We recently made an 036 chainsaw from a Huztl/Farmertec kit of non-genuine parts. It was fun and educational, and so far the saw is working well. Overall I think these kits are a great product for someone who wants to develop their mechanical skills and get a good chainsaw, at a low cost, that they know how to repair.

Choosing a saw

Recently, I was looking for a smaller chainsaw to use in thinning the forest on my in-laws’ place at Stanthorpe. 100 years of neglect has produced a forest which is dangerously overcrowded, mostly with black cypress, but also with small eucalypts, amongst the well-spaced old eucalypts. In its current form, the forest is fully set up for uncontrollable, crowning wildfires that would kill many of the old trees. Lots of it is now too thick to safely or productively carry a controlled fire, and it appears that manual thinning is necessary to produce a forest structure which can carry a cool fire, preserve the old trees and achieve maximum restoration of  the historic Aboriginal woodland.
The worst sort of cypress thicket, ready to burn to the canopy - or be thinned
When thinning this forest, most cutting is the small (mostly up to 100mm diameter) cypresses, which cut easily with smaller saws like a Stihl 025 or 026. However the stringybarks and the sandy country are very hard on chains and bars, especially the dead stems with very strong, dry, bark fibres and sand in and under the bark from ants. 
I find that bigger chain pitches work better in dirty wood: somehow the bigger teeth seem to get under the dirt and keep cutting even if a little blunt. A bigger chain and a stronger motor also makes it quick to prune the cypress branches, chopping the smaller branches off without having to stop and saw through. A Stihl 036 (62cc) with a short bar was looking attractive: only slightly heavier than an 026, but carrying 3/8” chain and a stronger engine which can work lazier and last longer. The 036 has some other desirable characteristics as well.

Repairable chainsaws

If you want a saw that can do a lot of work and last a long time, and you want to do your own mechanics, it’s important to know that some saws are more repairable and durable than others.
Some brands of saw are easier to get parts for, as well as being good quality. In Australia, Stihls are clearly the easiest to get parts for, including non-genuine parts. Husqvarna would be the second easiest, and appears to be Stihl’s main competitor for quality. In Australia, Stihl has a near-monopoly in chainsaws, with other makes being pretty unusual, with the exception of consumer saws in hardware shops, which tend not to have much spare parts availability or range of sizes, as well as most being of poor quality. My experience has been mostly in Stihl, so I prefer to stick with them.
Stihl chainsaws come in 2 distinct qualities, which are very different in repairability.
The older design type of saws, often described as “professional” saws, have a metal chassis which forms the structure of the saw. It comes in 2 cast magnesium halves with a vertical joint, sealed with a gasket, forming the oil tank and the crankcase, and having moulded flanges to carry the external parts of the saw. The cylinder bolts on top of this crankcase and is easily removed or replaced, without necessarily dismantling much of the saw. A worn or damaged piston and/or cylinder can be quickly and cheaply replaced. These saws are highly repairable and, unless they have serious accidents, can have almost indefinite life expectancies. When I first bought Stihl chainsaws, this was the only type of saw they sold. However it seems that market pressure pushed Stihl to produce another line of cheaper, less repairable saws for less intense use. The professional saws are still made and sold, at significantly higher price.
This is a typical metal chassis from a Stihl professional saw (in this case a Stihl 024), viewed from the flywheel side (see tapered crankshaft with keyway). Oil tank is on left, piston is on top (cylinder is removed). 
The same 024 from clutch side, bar studs on right. This saw is old and in poor condition, but quite repairable with non-genuine parts. Worst damage is corrosion around clutch, perhaps from corrosive palm tree sawdust.
The newer “consumer” design of Stihl has a plastic body that wraps around a more self-contained metal engine. The cylinder and the top half of the crankcase are a single metal barrel, and a metal pan is bolted on the bottom to close the crankcase. Removal or replacement of the cylinder involves a major dismantling of the saw, to extract the motor from within the plastic body.
This is the type of engine in "consumer" saws, which is bolted into a plastic body (I think this is for a Stihl 029)

The 2 different types of Stihl chainsaw can be generally identified by their model numbers, using a sort of Stihl numerology. In the old model numbers starting with a zero (mostly from the 1990s, when the modern designs started), the even numbers (e.g. 026, 036, 046) were the professional saws. The later odd numbered models (e.g. 017, 025, 039) were the plastic bodied consumer saws. With the new model numbers starting with “MS” (when for example the 026 was renamed the MS260), most of the professional saws now have an even number as the middle digit (e.g. MS381, MS461) and the consumer saws have an odd digit in the middle (e.g. MS170, MS250). This is not quite a perfect system, e.g. MS180 is a consumer saw.
For me, wanting a saw with an engine about 60cc, there are 3 Stihl options: the old 036 professional saw (no longer sold new, but available second hand or as a non-genuine kit), the MS361 which is a more modern and complex professional saw, or the MS391 which is the similar-sized consumer saw. My preference was for the 036, as it is a simpler design than the MS361, and more durable and repairable than the MS391.

Huztl non-genuine kits

Through watching youtube videos about chainsaw repair, I discovered the recently emerged option of buying a kit of “Complete repair parts”: a full set of non-genuine chainsaw parts, which can be built into a working chainsaw. The principle source of these kits is www.huztl.net (a name appparently made from “Husqvarna” and “Stihl”), who sell a huge range of non-genuine parts, mostly branded as “Farmertec”.
For anyone repairing their own chainsaws (or brushcutters etc.), the Huztl web shop is astonishing in its scope and its prices. The accessibility alone is revolutionary: Stihl parts are difficult to find without walking into a genuine Stihl dealer’s shop – you can’t browse or price parts online. The Huztl site has huge catalogues of parts listed with photos, viewable by chainsaw model.
The quality of parts sold by Huztl will take some time to discover. Some parts are clearly fine because they work from new, e.g. clutch covers, carburettors, bolts. Some will be quick to evaluate: chains, bars. Some, however, will take some time to be confident in: pistons, cylinders, crankshafts, bearings, seals. If the quality of Huztl parts is good enough (and I am so far happy), it offers a great resource to backyard chainsaw mechanics. The question of quality and durability is fundamental to my writing this entry, so I will try to report as well as I can on my experiences over time.

Ordering the 036 kit

The Huztl 036 kit is astonishingly cheap: mine cost about AU$300 delivered, plus bar and chain for another ~$25 (a new Stihl MS361 is listed at about AU$1600). I made the mistake of ordering parts for other chainsaws, along with the 036 kit, which meant we had some troubles working out what was what – most parts are not labelled. The kit does not include bar or chain, so I ordered these as well from Huztl. Currently the shortest 3/8” bar they sell is 18”, which is longer than I want, so I made a project of cutting an 18” bar from Huztl down to about 14”, see my post on this here.
I ordered a couple T-handled T27 tools with my kit. This is the main tool needed for tightening bolts. I also bought a Huztl crankcase splitter tool, in case we made a mistake and needed to open the crankcase. I bought a flywheel puller (2 in 1) tool, to make it easier to remove the flywheel in case of crankshaft seal trouble.
I also ordered some extra gaskets for the crankcase and cylinder, and some spare crankshaft seals. These seemed at significant risk of damage during assembly - we did need to replace one crankshaft seal we damaged while assembling the crankcase.

Assembling the 036 kit

Unboxing the parts on the kitchen table
Nearly all the assembly was done by our son Jasper, who couldn’t keep his hands off it. There are no instructions at all, and almost no labels on the parts. Luckily our neighbour and friend had a Stihl 036 we could borrow to look at and to exchange parts. Most importantly there is a rich resource of youtube videos specifically on how to assemble these kits.
Here are the videos we found most useful:
Afleetcommand’s 036 assembly series
Part 1:

Part 2:
Matthew Olson’s “bolt by bolt” 036 assembly series:
There were some other youtube videos on assembling the crankcase which were helpful, mostly found by searching for Huztl. As, well, I liked Andy Reynolds’ chainsaw repair series on youtube, which share some of his accumulated experience with chainsaw maintenance.
For most of these saw kits, construction begins with assembling the crankcase. For us, this was the only difficult bit. We used our wood-burning cooking stove to heat the 2 shells, and used a wooden mallet from our woodwork shop to make adjustments. We damaged a crankcase seal on the clutch side, but it wasn’t difficult to replace (for crankcase seal replacement see https://www.youtube.com/watch?v=znC1HfkCzC8&t=8s). With heat, patience, and a wooden mallet, it isn’t too hard.
036 coming together on the kitchen table
Once the crankcase is assembled, it’s just a matter of bolting everything else together.
The Huztl 036 - without an 036 label on the flywheel cover - otherwise looks just like any other 036

Carby troubles

Once assembled, I filled the fuel and oil, and adjusted the carby jet screws to 1 turn from closed (the standard startup setting). I was able to start the saw and run it at high revs, but I couldn’t get it to idle. There was clearly a problem with low speed mixture: adjusting the low-speed jet seemed to make no difference. After doing a crankcase pressure/vacuum test to see if we had damaged a gasket or crankshaft seal, I tried swapping carbies with our neighbour’s genuine Stihl 036. With a genuine carby the saw worked perfectly.
Huztl promptly sent a replacement carby once I sent photos of the non-working part. The new carby worked perfectly.
During the first few hours of use, I found the idle speed variable. Tilting the saw on its side would drop the idle speed and sometimes stall it. Again I worried about crankcase vacuum leaks (I’ve had some bad experiences…). I then realised that the idle speed ajustment screw wasn’t changing the idle speed. Looking closely, I could see that the throttle connection wire (from the plastic throttle finger lever to the carby) was a fraction too long, so the throttle butterfly lever wasn’t sitting on the idle ajustment screw. After I removed, slightly bent and re-installed the wire, idle speed was fully adjustable.

Bar and chain

I wanted to try the Holzfforma bars available from Huztl, but wanted a shorter bar than they supply: the shortest 3/8" bar they offer is 18". So I tried something I'd been wondering about for a long time: cutting a bar down to a shorter length. I did, and it has been quite successful, see my blog post about this at http://bruceteakle.blogspot.com.au/2017/08/shortening-chainsaw-bar.html . This post also gives more info about the quality of these bars. 
Overall, the Holzfforma bars are reasonable: very cheap, and fine to use if you are willing to set them up to start with and are attentive to maintenance. 
The Huztl chains also seem to be good. I was worried about them being soft and blunting quickly: they seem softish to file, but in use we have found them fine so far. Again, their cost is so low it is worth it to do a little more sharpening - but I can't say I've found they blunten noticeably more quickly. I've had to buy longer chain loops and shorten them for some bars, as they only come in particular lengths. 
Using the low cost Huztl bars and chains has given me confidence to try using waste deep frying canola oil (from a neighbour's cafe) as bar oil. This has worked fine, and doesn't appear to have led to a higher rate of wear. Again, even if the bar did wear a little faster, another $10 or $15 bar from Huztl is fine if it's saved me $100s in bar oil (and I've already saved a few 20 litre drums of expensive bar oil). Importantly, the vegetable bar oil means I'm more confident in using my sawdust for composting and garden mulch. 

Decompression valve

After the saw had done a few hours work, one day the plastic head from the decompression valve fell off. This was easy to repair: I peened the head of the valve stem a little so that it had a bit of a burr all around, so it couldn't slip down thru the valve body into the cylinder. Then I pushed the plastic head back on with some epoxy glue.
Same thing happened to the decompression valve on my Huztl MS660. Here's the cap that just fell off while sawing.  
Here's the Huztl decompression valve removed, showing the lid off the valve stem
I peened the top of the decompression valve stem with a hammer - you can see the mushrooming if you look closely on the left-hand end
The peened end is only slightly wider than the stem, but too wide to fit thru the valve body - so it's safe for the engine. After this, I warmed up the plastic head and tapped it back on (this time with no glue). It so far seems fine. 
I was concerned that the valve stem could cause major damage if it slipped into the cylinder. However I'm not sure how big a risk this is: the motor wouldn't run without the valve closed, and the spring in the valve seems to be pretty good at holding the stem in place. But it's a risk worth keeping an eye on: just pulling the engine over with the decompression valve stem rattling inside could do serious damage.

Flywheel key shearing

It's important to tighten the flywheel nut adequately, and to assemble a clean flywheel onto a clean shaft taper, to avoid shearing the key. This wasn't a problem on my Huztl 036, but my (later built) Huztl 066/MS660 did break down this way.
The 066 had been working fine after being built, but one day it wouldn't run properly. It would start, with difficulty, but ran poorly: it was smokey, wouldn't run up to speed, and wouldn't idle. It seemed like it was running rich, so after checking the mixture screws I took the carby off (twice!) and checked the float needle (if it's being kept open by some dirt it can cause flooding). When the carby didn't help, I thought of timing, then removed the flywheel and found the sheared key. 

Here's the crankshaft taper that holds the flywheel. The piece of key is still in the slot. I carefully picked out the piece of key so I could use it as a model for making the new one.
Here's the tapered hole in the flywheel, also with a piece of sheared key. 
I made a new key from mild steel (the key should be softer than the crankshaft) to copy the sheared one. I forged a small piece of flat bar down to 9mm x 2mm section, then ground and filed the bar end into the right arc before hacksawing off 4mm from the end.
I think I made 2 mistakes to cause the key to shear:
I tightened the flywheel nut with an impact driver (an impact driver is a very quick and easy way to remove the flywheel nut or the clutch body), instead of taking the time to do the proper bush mechanic's method: lock the crankshaft by taking out the spark plug and pushing in a length of soft cord (like rewind starter cord), then tightening the nut with a socket. It would have been even better to use a torque wrench (I should get one).
Also when I took the flywheel off the shaft, I found the tapered crankshaft end and the inside of the flywheel were greasy. I like to grease things as I assemble, but in this situation it would cause the flywheel to float on grease instead of bedding down tight. Then I read the workshop manual to find it advises cleaning the shaft and flywheel hole with degreaser before assembling (if all else fails, read the instructions…). 

Using the Huztl 036

Once carby problems were sorted, the Huztl 036 worked like a brand new Stihl. Compared to other cheap chainsaws, it has the advantage of Stihl’s excellent design. The 036 is a really good saw for my work, lighter than the Stihl 038 and MS381 that we have used a lot over the last 20 years, but still powerful and having the 3/8 pitch chain advantages.
Once the saw was working, I attached a cheap digital hour meter. This adds up the run time, so I can add up the short runs that are usual for chainsaws.
Here's the digital hour meter on the cylinder cover. A wire from the meter wraps around the spark plug lead
So far it’s done 15 hours, which is actually a lot of chainsawing: several days in the forest. It’s been a mix of long, light work thinning cypress (soft wood, small diameters) and hard, continuous, full throttle cutting dead stringybarks into firewood blocks. Nothing has broken or failed, and I’m very happy with the saw.
The 036 working in the cypress thickets

Is the Huztl 036 any good?

So far, I’m very happy with the Huztl 036. It’s fair to say it’s seriously changed my understanding of chainsaws.
The first advantage is that we needed to put it together. My son and I learnt a lot from making it: once you put a machine together like that, it is never a complete mystery again. We know every part, and feel confident that we can deal with mechanical problems.
Easy, low cost access to a complete range of parts for these kit chainsaws, that appear to be of good-enough quality, is also pretty revolutionary for chainsaw users like me. It stops chainsaws being throw-away consumer goods when there is a breakage or failure – not necessarily because genuine parts aren’t available, but the cost of genuine parts and dealer labour is often too big a risk for an old saw which might have other problems. If a saw you made yourself wears out a piston and cylinder, and the parts cost AU$30 to replace and you have confidence to do it yourself; then that saw is likely to be repaired and work on. 
Remember that the low money cost of these parts is balanced by the need to be your own mechanic and do some quality control for yourself. It’s very different from stopping off at the Stihl dealer and picking up a new saw that is immediately ready for work. If you do buy these parts, be ready to take the time to check the parts, put things together carefully and if needed, to ask for replacements. 



4 comments:

  1. Hi Bruce,
    Good to read your blog on the Hutzl 036 saw, I have one of there 036 as well and a 066, as you say they offer a good value for money product with the ability to repair at a reasonable cost.
    I was in the repair workshop of a Stihl dealers in the UK for 38 years and as you say these are copys of the professional saws with the clamshell cases, I also have limited time on my 036 but am very pleased with it so far, I've changed the oil seals for the replacement Hutzl ones that seem better than the ones supplied with the kit, there was also a small rubber gromit missing from the kit that goes between the air filter and the carb at the bottom where it meets, if this is missing it can draw clippings into the carb causing problems, this seam to be common.
    Thanks for the good read!

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    Replies
    1. Thanks for your feedback Peter, it's reassuring to hear from someone with so much experience. As you say, the grommet at the bottom of the air filter (I wonder if it is for adjusting the mixture when the filter is clogged?) seems to be missing on all the Huztl 036 air filters, leaving an open hole in the filter. I tried gluing on a piece of inner tube, but this didn't last long in the oily and petrolly environment. I've recently tried forming a gasket in place with silicone - I'll see if it lasts.
      How do you approach assembling the crankcase - any advice?

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    2. Hi Bruce, the small rubber piece between the carb and the airbox just allows the diaphragm to breathe clean air on it's air side, a lot of carbs just have a small hole in the cover plate to do the same job.
      Crankcases are relatively straight forward,gently heat the case with a hot air gun or blow torch taking care not to efect the paint while keeping the bearing somewhere cool, I've never found it necessary to use an oven or fridge for bearings or crank but if you are working in hot conditions then a fridge could help, then just drop or tap the bearing home, the heat transfer is very rapid so it needs to be in one easy movement so have everything you need to had with the workspace clear, repeat for the other side.
      Then heat the side of the crankcase with the location pins in it again taking care not to efect the paint or bearing cage, they can take a lot of heat so it not as crucial as it sounds, then take your crank and drive it in with a hide/nylon/copper head mallet, again heat transfer is very quick so keep everything to hand, after allowing that to cool place your gasket with any sealent you wish to use on the side that now has the crank located, heat the other side of the crankcase and bring them together, you will normally get enough on to locate the pins but it probably won't allow you to completely close the case before the heat transfer locks it up, then just put the crankcase screws in and tighten them diagonally taping the crank with your mallet, when it's closed up give the crank a few good taps each side to seat it home, the crank should then turn by hand, job done!

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    3. Thanks very much Peter for your advice - I look forward to trying it out (but I can only use so many chainsaws!).

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