Stihl MS-290 3/8" Drive Conversion?

[Ray K]

I bought a Stihl MS-290 (eBay) that came with a 18″ Rollomatic ES 3/8″ Chainsaw Bar (3003 000 9417) and 3/8″ chain.

While inspecting the saw, I found that it is still driven by a .325 8T sprocket.

I do not know if the previous owner ran the saw with a .325 8T sprocket and 3/8" chain - I will not.

I either I get a new clutch drum with a 3/8" 7T sprocket or buy a .325 bar and chain.

Per Bailey's, 3003 000 9417 fits the MS-290 so it may be cheaper to go with a new sprocket.

What's the best option, run with 3/8" or reconfigure for .325?

Is there anything else I need to replace beyond a 3/8" sprocket?

 

[cus_deluxe]

ideally you can get a rim drive clutch drum, so then you can switch just the rim for a few bucks and see what works best for you. that saw should pull a 18” 3/8 setup just fine

 

[farmguywithasaw]

Ms 310 came standard with 20” 3/8 and is only 3 more ccs

 

[dmb2613]

To answer your question, yes check the chain closely , if ran on that 325 sprocket very long it will be toast and tear up the new sprocket

 

[Ray K]

A rim drive clutch drum you say? The drum is configurable with rims then?

 

[stihl86]

I have an MS290. I use 3/8 super on it and it pushs a 20" chain without even breathing hard. That family saw started with 3/8 then the white coat guys dropped it down to .325.
Maybe it cuts a fraction of a second quicker. That would be enough for them.
I'd put a 3/8's spur sprocket on it and go.

 

[Ray K]

Any issues using an aftermarket clutch drum w/sprocket? Much cheaper than Stihl branded.

 

[ammoaddict]

Any issues using an aftermarket clutch drum w/sprocket? Much cheaper than Stihl branded.

Some of the after market ones are good, Oregon for one. The Chinese ones are hit and miss. Some are actually pretty fair and some not so much.

Sent from my Moto G (4) using Tapatalk

 

[r1stgei]

A rim drive clutch drum you say? The drum is configurable with rims then?

If you have a spur sprocket (which is sounds like you do) then you will need to swap it out to a drum that will take a rim sprocket. Once you have one you can flip between different pitches.

Honestly tho.... if the original owner ran that chain with those miss matched pitches , the drive links probably toasted... so you need a new chain anyhow , you may as well grab a .325 chain and get a new bar...

 

[r1stgei]

Some of the after market ones are good, Oregon for one. The Chinese ones are hit and miss. Some are actually pretty fair and some not so much.

Sent from my Moto G (4) using Tapatalk

Oregon makes good stuff. The amazon stuff forget it. I have yet got an AM spur sprocket drum that worked. I do buy AM rim sprockets that work great tho. Stay away from amazon spur sprockets. (And clutches for that matter)

 

[farmguywithasaw]

My dads ms290 is 325 and it seems to get chip bound fairly easy. I think with 3/8 you would eliminate that