Air filter difference 029S/MS390

[fidiro]

Decided to take the filters from both saws and soak them in warm water and dish detergent and notice that there is a difference between two. The 390 has that opening that goes into that little rubber boot at top of carb, 029S is closed off.

Does the MS290 have it closed off as well?

I just thought all parts were identical except for p/c and carb jets between 390 and 029S/MS290's. I'm just looking to see if I should open it up to get more air or to leave it as is.

One of these days I'll get the picture posting right.

Finally pic is big.

 

[oscar4883]

That is for the compensating carb. Just leave that hole as it is from the factory. Not sure if the 029/290 series had that carb feature or not.

 

[fidiro]

Thanks oscar. I'll leave it alone for now if that is how it came from factory.

I have been wondering though if the previous owner replaced the air filter and bought one for the 029 (54cc) instead of the 029 Super (56cc), if there is a difference between filters on the two.

I don't know if the MS290 is opened like the MS390 but if it is, shouldn't the 029Super be open as well? 029S and MS290 have identical specs.

Also, looking through ebay I find that most advertise the filter to work on 290/310/390 and LATER 029's. Later 029's I'm assuming is the Super.

 

[oscar4883]

That compensating port is a non-issue when it comes to performance in the way I think you mean. Someone can probably explain it in detail, but basically it is there to keep the saw running evenly if the air fiter gets very dirty IIRC. Lots of saws. 026, 064, 066, didn't have then depending on the age and model. Messing with that port is not going to make things "flow" better. Its not needed for you because you obviously take good care of your filters. lol

 

[fidiro]

Thanks. I just wanted to make sure I'm using it correctly and the right one on the saw. I guess if saw is properly tuned and filter always clean it shouldn't have a need for more air.

The MS390 filter is still original so I know it's right.

 

[brages]

Does the MS290 have it closed off as well?

No, the ms290 has the port for the intellicarb. At least the one I looked at did -- you never can be too sure with Stihl specs.

 

[fidiro]

No, the ms290 has the port for the intellicarb. At least the one I looked at did -- you never can be too sure with Stihl specs.

Thanks. This confirms that MS290 is just like my 390.

Anyone have a 029 SUPER (56cc 46mm piston) to check original filter?(if it still has the original filter)

 

[BiodieselNC]

My MS290 does have the intellicarb with the extra port on top. My buddies 039 does not have the top port. I believe when they switched from "0" to "MS" around that time they added the intellicarb on these saws. I think the 029S and 039 would share the one carburetor and the 290/310/390 would all share the new intellicarb

 

[fidiro]

I don't know what an intelicarb looks like but my 029S has that port on the Carb with the rubber coupling that connects that part of the filter, that is closed off, to the carb. Looking through that rubber coupling into that carb port, you can tell it's open into the carb, meaning carb would suck air through port IF filter had a hole.

Without a hole in the filter, my carb has no purpose having that coupling/port on my saw. That's why I'm wondering if the previous owner changed filter or even possibly threw in a new 290 carb and just kept the 029 air filter. :dunno: I'm just trying to make sense of having a carb with an open port but with a filter with a closed port.

Curious what other 029 Super owners can tell me about their carb./filter setup.

 

[fidiro]

Here's a couple of pics I had of my 029S carb when I rebuilt it.