Rings old new

[RedneckChainsawRepair]

Dont be scared to tear down those saws and refresh them when getting easy to pull over.

394 and 372 OE rings. 372 was down to 120psi.

Check those piston skirts then too. 372 p was good to go. 394 will need a piston.

 

[Roanoker494]

At 120psi you are about down to completely useless anyway. Nothing to loose at that point. I am a tinkerer. When I'm done it will either be fixed or two mechanics and a Voodoo Witch doctor won't be able to bring it back.

 

[Huskybill]

A compression gauge can be your friend. I still think the 50:1 ratio is too oil lean.

 

[Bob Hedgecutter]

Dont be scared to tear down those saws and refresh them when getting easy to pull over.

394 and 372 OE rings. 372 was down to 120psi.

Check those piston skirts then too. 372 p was good to go. 394 will need a piston.

View attachment 936272View attachment 936273

Don't need no micrometre to see the differences there.
Those old rings can be retired with pride- they have done an honest working life and paid their due taxes.

 

[Huskybill]

Don’t wait too long to restore the compression. Do it while the cylinder is still ok. Check the compression often to setup a baseline.

 

[Bwildered]

I still think the 50:1 ratio is too oil lean.

Why? Don't you know how rings work in relation to excessive oil on the cylinder walls?

 

[Huskybill]

Husqvarna advises when running longer bars use 32-1 ratio why?

 

[rogue60]

A compression gauge can be your friend. I still think the 50:1 ratio is too oil lean.

50:1 is great for halving the life of a saw, but I don't see the problem there not my saws lol
Most don't even understand how oil works in an engine/engines with all the myths about oil getting around now day's.

It's basic stuff oil seals the rings and prevents metal to metal contact(rings contacting the cylinder walls) it's that simple. On there own rings will not do a very good job at sealing against the bore and fuel is terrible at this job also, the more oil the better the ring seal that's fact. No race team is running less oil for more power and longer engine life in a 2T.
The only time metal to metal contact happens by design in any engine is during break-in seating the rings.
In a 4 stroke the oil rings wipe straight oil on the cylinder wall resulting in an impressive engine life.
In a 2 stroke the less oil in the mix is better myth just results in a thinner oil coating on the cylinder wall. This can promote excessive wear through metal to metal contact i.e. worn rings/worn cylinder/worn piston skirt.
Not to mention the piston will start to transfer itself onto the cylinder wall if things get anything close to remotely hot due to such a thin inadequate oil coating on the cylinder wall.
A lot of the blame for worn out part's is allegedly fines getting past the fitters on chainsaws most completely overlooking there has been metal to metal contact going on.

I personally run straight fuel in my 2 Strokes for long engine life never had a problem.

 

[Huskybill]

Make sure the piston is good, the pin that holds the ring from turning is tight. If that pin comes loose it can dig into the piston wall and cylinder.
Husqvarna cylinders and pistons come in different diameters. A letter should be on top of the cylinder and piston tell you what bore size you have. Ring gaps matter too.

 

[Bwildered]

50:1 is great for halving the life of a saw, but I don't see the problem there not my saws lol
Most don't even understand how oil works in an engine/engines with all the myths about oil getting around now day's.

It's basic stuff oil seals the rings and prevents metal to metal contact(rings contacting the cylinder walls) it's that simple. On there own rings will not do a very good job at sealing against the bore and fuel is terrible at this job also, the more oil the better the ring seal that's fact. No race team is running less oil for more power and longer engine life in a 2T.
The only time metal to metal contact happens by design in any engine is during break-in seating the rings.
In a 4 stroke the oil rings wipe straight oil on the cylinder wall resulting in an impressive engine life.
In a 2 stroke the less oil in the mix is better myth just results in a thinner oil coating on the cylinder wall. This can promote excessive wear through metal to metal contact i.e. worn rings/worn cylinder/worn piston skirt.
Not to mention the piston will start to transfer itself onto the cylinder wall if things get anything close to remotely hot due to such a thin inadequate oil coating on the cylinder wall.
A lot of the blame for worn out part's is allegedly fines getting past the fitters on chainsaws most completely overlooking there has been metal to metal contact going on.

I personally run straight fuel in my 2 Strokes for long engine life never had a problem.

Rings needs a microscopic amount of oil for long life, 2 or 4 stroke, oil burnt on the cylinder walls creates a carbon rich compound, carbon is an abrasive, more oil = more abrasive, less oil = less abrasive .
Power and ring seal from more oil is a different matter completely

 

[Pepster]

I went to a hockey game & a oil fight broke out!

 

[Bwildered]

Husqvarna advises when running longer bars use 32-1 ratio why?

To stop them blowing up,

 

[Bob Hedgecutter]

Husqvarna advises when running longer bars use 32-1 ratio why?

Because they figure when all you good meaning folk use 30 + inch bars on 70cc saws you are over taxing them- so they cover their arses (butts for all the US readers)

 

[rogue60]

Rings needs a microscopic amount of oil for long life, 2 or 4 stroke, oil burnt on the cylinder walls creates a carbon rich compound, carbon is an abrasive, more oil = more abrasive, less oil = less abrasive .
Power and ring seal from more oil is a different matter completely

If you personally have problems with carbon that's more to do with your ability to tune a saw and/or a false belief in the oil you use is better than it actually really is at doing it's job. I'd recommend changing both of the above.
I understand your stance on oil and how in a two stroke it's more abrasive than sand etc etc...
I can't be bothered getting into it the whole oil does more harm than good thing with you I would have better luck convincing you the world isn't really flat lol.

 

[Bwildered]

If you personally have problems with carbon that's more to do with your ability to tune a saw and/or a false belief in the oil you use is better than it actually really is at doing it's job. I'd recommend changing both of the above.
I understand your stance on oil and how in a two stroke it's more abrasive than sand etc etc...
I can't be bothered getting into it the whole oil does more harm than good thing with you I would have better luck convincing you the world isn't really flat lol.

I don't have any problems with carbon, tuning has nothing to do with what I am talking about, it's the oil in the fuel mixture and burning oil produces carbon, fuel & oil mix goes in one end & carbon comes out the other. one of my jobs many moons ago was to monitor GM & CAT gensets, they used to have a full rebuild after 20,000 hrs whether they needed it or not & could be pushed to 30,000hrs before they'd start dropping valves, then some bright spark decided to go on a energy saving quest so the energy demand wasn't enough to work the engines hard enough, in under a year five 3306 CAT gensets were toast, worn out & couldn't keep oil up to them because the rings and cylinders were worn out, the bores glazed, which allowed oil to get past the rings & be burned in the cylinders , it was over for those engines very quickly from there on in, quality two stroke chainsaw engines have chrome or nikasil bores which have superior wear resistance to those cylinders, but the principle is the same.
Also the gensets were running Mobil 1 full synthetic oil.

 

[RedneckChainsawRepair]

50:1 is great for halving the life of a saw, but I don't see the problem there not my saws lol
Most don't even understand how oil works in an engine/engines with all the myths about oil getting around now day's.

It's basic stuff oil seals the rings and prevents metal to metal contact(rings contacting the cylinder walls) it's that simple. On there own rings will not do a very good job at sealing against the bore and fuel is terrible at this job also, the more oil the better the ring seal that's fact. No race team is running less oil for more power and longer engine life in a 2T.
The only time metal to metal contact happens by design in any engine is during break-in seating the rings.
In a 4 stroke the oil rings wipe straight oil on the cylinder wall resulting in an impressive engine life.
In a 2 stroke the less oil in the mix is better myth just results in a thinner oil coating on the cylinder wall. This can promote excessive wear through metal to metal contact i.e. worn rings/worn cylinder/worn piston skirt.
Not to mention the piston will start to transfer itself onto the cylinder wall if things get anything close to remotely hot due to such a thin inadequate oil coating on the cylinder wall.
A lot of the blame for worn out part's is allegedly fines getting past the fitters on chainsaws most completely overlooking there has been metal to metal contact going on.

I personally run straight fuel in my 2 Strokes for long engine life never had a problem.

The gas race saws back in the day got 24:1 and the ported work saws got 32:1. Today since I dont run ported stuff everything gets 40:1.

I will never be a sheep and let EPA that tell US shops they have to tell customers 50:1. Read about that. They have to tell you 50:1 no if's about it.

Enjoyed the read.

 

[rogue60]

I don't have any problems with carbon, tuning has nothing to do with what I am talking about, it's the oil in the fuel mixture and burning oil produces carbon, fuel & oil mix goes in one end & carbon comes out the other. one of my jobs many moons ago was to monitor GM & CAT gensets, they used to have a full rebuild after 20,000 hrs whether they needed it or not & could be pushed to 30,000hrs before they'd start dropping valves, then some bright spark decided to go on a energy saving quest so the energy demand wasn't enough to work the engines hard enough, in under a year five 3306 CAT gensets were toast, worn out & couldn't keep oil up to them because the rings and cylinders were worn out, the bores glazed, which allowed oil to get past the rings & be burned in the cylinders , it was over for those engines very quickly from there on in, quality two stroke chainsaw engines have chrome or nikasil bores which have superior wear resistance to those cylinders, but the principle is the same.

All engines eventually wear out.. its just a guess but I'm sure removing oil would speed this process up.
Not sure what that has to do with a chainsaw diesels run different fuel and oil than a 2T saw.
I get that Diesel engines under combustion coat the whole bore with carbon and soot the piston/rings has no choice but to go back up through that mess, of course some of that carbon makes its way past the rings you only have to look at the black oil to see this. But does this even matter in diesel engines they are an impressive hard working engine out working a lot cleaner combustion burning engines.

Here's a worked hard 1st gen ms880 (only thing different to 088 is it has flippy caps) being conservative on the low side it has a thousand plus hrs. They are known for smearing piston on the exhaust side running 50:1 if worked hard.
This saw was tuned for and run on way more oil than 50:1 its whole life and mineral oil at that.
I can't see any problems damage or premature wear because of abrasive carbon during the combustion process?.. only thing I see is the oil has done a good job doing it's job preventing metal to metal contact, load side piston skirt wear is minuscule for a high hr saw. Good ring seal as well no signs of blow-by..

 

[Bwildered]

All engines eventually wear out.. its just a guess but I'm sure removing oil would speed this process up.
Not sure what that has to do with a chainsaw diesels run different fuel and oil than a 2T saw.
I get that Diesel engines under combustion coat the whole bore with carbon and soot the piston/rings has no choice but to go back up through that mess, of course some of that carbon makes its way past the rings you only have to look at the black oil to see this. But does this even matter in diesel engines they are an impressive hard working engine out working a lot cleaner combustion burning engines.

Here's a worked hard 1st gen ms880 (only thing different to 088 is it has flippy caps) being conservative on the low side it has a thousand plus hrs. They are known for smearing piston on the exhaust side running 50:1 if worked hard.
This saw was tuned for and run on way more oil than 50:1 its whole life and mineral oil at that.
I can't see any problems damage or premature wear because of abrasive carbon during the combustion process?.. only thing I see is the oil has done a good job doing it's job preventing metal to metal contact, load side piston skirt wear is minuscule for a high hr saw. Good ring seal as well no signs of blow-by..
View attachment 936571View attachment 936572

What is the ring end gap? And what is the ring end gap of the same saw at 50:1 that's done exactly the same amount of work?