Chainsaw and 2 stroke maintence

[Old Dog]

Stihl MS180 out of a 2006 saw that has been run hard and on Stihl HP super and E10 petrol.

 

[AVI_8]

RE carbon buildup- what oil do you use?

I use Stihl HP Ultra which is supposed to help with reducing carbon deposits but I've never had one apart after running on it for a significant time to confirm myself.

What is The Role of Engine Oil in a STIHL 2 Stroke Engine? | STIHL Blog

Engine oils have a critical role to play in the workings of a 2-stroke engine and without good quality oil, your engine may not last and won’t perform at its best.

blog.stihl.co.uk

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I’ve been using Quicksilver 2 stroke oil for outboard boat engines.
It’s a known good quality, but not the cheapest.

 

[JOEPRO]

Likely due to short runs, I imagine it would have cleaned and burnt off a lot of it with a bit of use. Perhaps my mix was a bit rich on oil.

I refused to buy ultra as they do t have any closeup pics of the bottle and appear to have a spec misprint on all the sites selling it as Jaso-FB in which case its poo!

My oil is all Jaso-FD which is highest standard and should be way more than adequate.

I have Stihl HP super and Castrol POWER1 2T Motorcycle Oil, seems to smell a little nicer but probably not the same as the legandary Castrol stuff.

https://www.amazon.co.uk/dp/B0C813TSXN

PS in that link Stihl did provide comment on this as follows:

• STIHL GB31st May 2022 at 9:27 amREPLY
  Hi, thanks for your comment. HP Super is a semi-synthetic, low smoke, low ash oil which is a very good all round performer. HP Ultra is our most premium, fully synthetic oil with the best lubrication, cold start properties and is also bio-degradable. HP Ultra is our best oil in all JASO categories except for “Low Smoke” . HP Super fulfils all the demands of JASO FD including low smoke which is why it appears to have a higher certified rating. The L-EGB and L-EGD have the same requirements as JASO FB and JASO FD respectively, with an additional test for piston cleanliness.
  Thanks, STIHL GB

So basically they say it is higher performing in all regards but doesn't meet the low smoke criteria which is a trade off then. For me if Stihl say the Ultra is the best oil I'll keep using it

In fact my saws have never ran cleaner on the Ultra oil so that bit surprises me a bit that it's not classed as low smoke. When warmed up my saws have no visible smoke at all at full revs.

 

[Kram]

I wouldnt always believe what they tell you.. if it doesnt meet a standard then you need to check if the tests are publish a d not take their word for it.

Theres a reasonable number of experienced saw builders on YT that warn against Stihl oils and I dont believe its just tin foil hat consipiracy theories. Its on their interest for tools to run cleaner but have earlier lubrication failures.. they last too long!

Anyway I believe any Jaso FD oil should be adequate for a cheap clone of an old saw design. Something I will keep an eye on.

Some recommended a richer oil mix for the running in period and technically my 372xp is still on its first gallon of fuel.. possibly I leaned out the high screw too much and I will check with the tacho when I get it back together.

 

[Kram]

The pock mark's in the cylinder head look like pre ignition OR very poor casting, looks worse in the squish band.
Did it have a base gasket and is the ignition adjustable?

Appears I should check the squish on the original and the new one. It appears 20 thou/0.5mm is the ideal amount of squish?

Peices of solder stuck to the piston with grease, or poked down the plug hole, seems the way it is normally measured?

 

[dobbslc]

I use oiled bluetac, squish it then cut it carefully with a scalpel and measure it.

 

[Migmac]

Poked in the plug hole appears to be the most common way of doing it

 

[Kram]

Next question is, it appears most pistons should have a little slot in the wrist pin bore for removal of the wrist pin clip, these do not.
The clips supplied, and originals, have ears for easy install/removal, but it seems these can break off and wreck an engine.
How important is that? I could cut the ears off and grind a little slot in piston to allow removal.
I just looked up cbr600 pistons and they have earless clips and a slot, as might be expected.

Test fitting the 20" .325 bar chain and sprocket. Somone said Id need longer chains when going up a sprocket size and I have possibly gone up by two if its intended for a 7 tooth (which cant fit this saw).
Simple solution is to cut a bit off. The bar slot is not a Husq so needs to be widened for the silly enlarged studs, so I may aswell lengthen the slot at the same time! I think the oiler hole is still good may need to poke a new adjuster hole in there too.

 

[Migmac]

Here’s the what I use . It has just one “leg” that goes towards the centre of the gudgeon pin. I’d just lengthen the chain

 

[Kram]

You can see the little slot and the earless clip as an example.

I'm yet to make a chain spinner. £60+ to buy one. Perhaps I should get it made as would be useful but modifying the bar is quicker and still needs the slot widening.

 

[Migmac]

I’ve never worked on that type, the one in my picture is Husqvarna. I personally can’t see an issue using a clip like I have but the manufacturers of yours have designed it to be that way. It’ll stop the clip spinning which will stop it coming off while in use. Never seen that but Ive heard folk on about it.
I use a basic chain breaker, the punch that comes with it and a hammer. Been doing chains this way for over 40 years, a spinner makes a tidier job though.

 

[Kram]

I use a basic chain breaker, the punch that comes with it and a hammer. Been doing chains this way for over 40 years, a spinner makes a tidier job though.

Have a photo? Is it same sort as a motorcycle chain braker? I have a DID style one.

 

[Migmac]

Can do chains from 1/4 and up

 

[Kram]

I was needing to use the saw and put it back together with the original cyl and piston, decided it may not be worth the effort so I will return the big bore kit. The lumps in the cyl roof are the main reason. Some YT videos say the ports are bigger in the wrong way and they do look taller, perhaps effects timing?

I measured the squish at 0.75mm, where the ideal is supposed to be about 0.5mm. This means I could likely remove the base gasket or get a thinner one?

It is running well, starts every time now, unlike the 020T, that needs an inspection. Perhaps just spark plug. It runs fine once its started.