Fixing a Stihl HS80

[Vissertw]

Hi, I am working on a Stihl HS80 and have some questions about it.

First, what could be the age of it, my guess is somewhere in the 80's?
And if so, what would be the right oil mixture, I have read something about Stihl having its own fuel, which would be the same as the Aspen fuel being 2%, isn't that a bit too lean for an engine of the 80's?

Second point, I have cleaned the carburetor, everything looked ok so put it together again but when putting it in place again I noticed something:
There is a gasket between the black nylon block and the carburetor, that block has 5 holes, one is the big one in the middle, two other holes are for the bolts, and there are two small holes opposite to each other, I assume they are for the pump function. The gasket has the same holes situated on the same place.
But when I look at the carburetor body, one of the two small holes is not situated in line, does that matter?

Another point is the air filter, when I checked it I found a piece of carpet with the text inside on it and a piece of thin foam, is that correct, can I replace it by some other air filter material?

I found only one mixture screw on the carburetor, would it be wrong to screw it in to the end, gently of course, and then screw it back one whole turn as a basic adjustment?
And one idle screw of course, that should not be so difficult to adjust I suppose.

So far with my questions, I hope to give it a try as soon as possible.

Regards,

Ton.

 

[Fish]

Here is the date range.

 

[Fish]

The gasket is made that way, so it can be used fine on either side/direction. Under the gasket/carb, is usually a channel that leads to the impulse passage.

 

[Fish]

Just wash the filter in hot soapy dish liquid and re-use.

 

[Fish]

Here is a bulletin on the carbs.

 

[Vissertw]

Thank you so far, so it should not be older than about 20 years. Ok, which means it can run on a 2% mixture?
I will try and make some pictures of the carburetor tomorrow, keep thinking about the hole being blocked.

Regards,

Ton.

 

[StarTech]

Fish, I suppose you know that is the wrong adapter setup for the 4226 engine.

 

[Fish]

Yeah, it is for a trimmer.
I don't sell hs80 parts, but needed a pic for example.

I think that I have a junk one out in the shop,
but I am not that ambitious....

 

[Vissertw]

Maybe not the best picture but it shows what I mean, On the gasket the two horizontal holes are in line, the same position as the black nylon block on the engine.
As you can see, the two smal holes on the carburetor body are not in line, the left one on the picture which is situated more down does not mach the hole in the gasket nor the hole in the black nylon block.
Hope you understand what I mean, English is not my native language.

And again my question on the fuel, is 2% oil correct, in that case I can buy Aspen, or should it be more?

Regards,

Ton.

 

[StarTech]

If I remember correctly the hole on the primer side is not used; only the one on the fuel pump side is used on that Zama. The hole on the primer may not even be fully drilled through.

As for fuel it is a 50:1 Fuel/Oil mix or for US measurements 2.6 oz of oil the one US gallon (128 oz) but I would recommend using a Pro grade multi mix oil that is already pre-measured for either one gallon or 2.5 gallons fuel mix.