David Heaf

Domusa Bioclass NG ( https://www.youtube.com/watch?v=Uo7GCK1nv0k ) Installed 2015 Updated 2019 with HM43 burner, main circuit board & display Power output 43 kw Currently heating an 8-bedroom house It comprises two units: Hopper 5ft high, 2 ft 6 in wide, 2 ft 6 in deep Burner 4 ft 6 in high, 2 ft 2 in wide, 3 ft deep The recipient would have to remove it at their own expense. As there are isolating valves on the pipe connections, removal should be easy. Location LL52 postal district of NW Wales.

It is indeed! It's as powerful as the one I bought in the early 1980s, which is the one with the failed pull start. Thanks for the repair tip. I meant 'pleasant'. I misread the author name. So thanks again!

Thanks Dan & Chris! I followed Dan's instructions and all went smoothly (the circlip was safely in another room when the spring 'exploded'). But the spring itself turned out OK. The pulley side against the spring is sound. In short there's no obvious reason why one turn of the spring was displaced enough to impede the pulley. Anyway, I'll renew the spring when I reassemble. On the rare occasions that I return to this forum, I always find it very helpful including being able to buy a spare Sachs Dolmar 123 from a member. (It's still running well Steve!)

Today the pull start on my 40+ year old Sachs Dolmar 123 failed. The rope stayed out after starting but retracted due to vibration when the saw was cutting at speed. This means the spring is working. After removing the unit and testing pull/retraction I can see that the rim of the inner side of the pulley (the outermost when on the saw) is rubbing on the spring in the region of the blue arrow shown in the photo. When pulled, the rope stays out only when pulled to its full extent, but can be retracted by turning the pulley manually. A coil of the spring appears to be dislocated. I've so far hesitated to dismantle further because the spring can 'explode'. Has anyone here got any diagnostic suggestions. I've ordered a replacement spring (# 123 163 010) in case the spring is the cause.

Yes indeed, but thanks for checking it. Getting a new needle roller bearing for it was not easy. The Makita replacement part has a plastic cage, whereas the original Sachs Dolmar's was steel. In the end I found one with a steel cage at a bearing specialist in Germany.

That would be useful information to have, but please do not dismantle your saw specially to measure it! The original drum, which a 16372X Oregon rim sprocket drum replaces, is 74.23 mm outside diameter, 69.24mm inside diameter, centre hole 17.93mm, depth of drum near outer edge 20.37mm, overall depth of unit including spur sprocket 30.29mm.

My enquiries in 2017 to 10 possible suppliers of this part all resulted in them saying it was no longer available or obsolete. Just now, typing in '16372X Oregon' on Ebay yielded two new ones in the USA, one of then costing less than £30 with postage. It may be worth enquiring to Makita/Dolmar dealers in Germany. Thay may even have the original spur clutch drum marked as 113 223 091 on my Sachs Dolmar 123 parts diagram. Not sure what the Makita part number is for his.

Thanks to all for very helpful suggestions! Yes, it was a case of the Oregon chain being harder than the new Oregon 7/32" file I am using. I suspected work hardening was the problem. The last ~90 min session yesterday on a 24" ash trunk may have caused it. It was not the sharpest of chains before that session, although I'd given each tooth two or three strokes of the file beforehand. As it is a 52-teeth chain and they are still 5.5-6mm long I was reluctant to follow the 'throw it' advice. So, mindful of the work hardening possibility, I ground the hard teeth with a Lidl 'Florabest' chain sharpener. (I'm a bit skeptical as to whether that device gets the angles right, even when set up correctly. For example, my saw (Sachs Dolmar 123) manual says the leading edge if the tooth should be at 85 degrees to the bar.) To avoid the risk of overheating the teeth, I ground each one slowly, taking off only a small amount of metal. The result is that the file bites again, and I was able to finish filing the teeth to the recommended 30 degrees angle with a 10 degrees tilt of the file relative to the horizontal.

If this is the right place to ask: my chain sharpening question is how to deal with sharpening when a brand new 7/32" file set in an Oregon file holder and used at the correct angles on the correct sized chain/teeth will not bite into the metal of the teeth. The file skids over the metal and gets blunted (reflects light from the tips of its 'blades'). Sharpening chainsaw teeth with a file has worked these past 39 years, so what's gone wrong? Could the teeth become so work hardened that the fille won't penetrate them?

So there's a case for grinding a commercially available depth gauge tool to the correct 0.63 mm depth. I've been using the Dolmar one that is rated 0.63mm but is 0.40 mm actual, for 37 years and had no cause to complain. The saw is 70cc so would no doubt cope with the proper depth of cut.

I have two depth gauges marked 0.025" (0.63mm), one an Oregon (part no 21830) and the other a Dolmar (complete with bar slot cleaner hook). Neither are noticeably worn. I noticed that more of the chain's depth gauge (raker) projects with the Oregon one. So it set me measuring them with digital calipers and a straight edge. The Oregon one was 0.45 mm and the Dolmar 0.40 mm. So neither of them were the stated 0.63 mm and thus result in a shallower depth of cut. Has anyone else looked into this issue? Does a loss of at least 0.18 mm in cutting depth make much difference? Does anyone check their depth gauges to verify whether they are as stated?

I use my Sachs Dolmar 123 routinely and have been very pleased with it these past 37 years. The second one I bought three years ago as a backup from 'spudulike' on this forum runs well too. The only snag with the 123s is the 8.5 kg with bar. I've just bought a Sachs Dolmar 100 weighing ~4.5 kg for lighter work.

I read somewhere that it means there is no needle roller bearing supplied with it. Do you know where at the moment in the UK I can get this part (Oregon clutch drum 16372X for rim sprockets to fit a Sachs Dolmar 123)? The last compatible part I got came from a Makita dealer as part number 957223123, but they say it is no longer available.

I considered using veg oil but was concerned that it may form deposits in the oil tank, pump or oilways when the saw is left unused for several months at a time. Do you have any issues like that? Also, I read that the biodegradeable oils such as the the one Bosch sells for their AKE range of electric saws, and which seems not to come cheaper than £9 a litre, have stabilisers and anti fling additives.

Though the person in question has a tractor ideal for the job, he's hopeless at changing over equipment. A mower is attached most of the time. So it would have to be a stand alone splitter. There is a single phase power supply to hand, but petrol/diesel would also be acceptable.