Which MS271 do I have?

[MS290man]

Picked up an MS271 off EBay that looked new but had a scored piston. It measured 90 psi on my compression gage but I decided to go ahead and tear it down. The unit looks like it was run without oil but the cylinder looked like it was salvageable (piston is trash). I was able to clean up the cylinder but when I went looking for parts I noticed that the diagrams available online don't match the unit I have. I ordered an OEM piston per the part # on the diagram and the one I received is slightly different than the one that came out; the diameter is correct but the cutouts on the sides (adjacent to the area where the wrist pin goes in) are all the way across on the old piston, only 2/3 of the way across on the OEM replacement. Also the rubber boot between the carb and the cylinder has a hose clamp attachment, not the 3 bolts with a flange as shown on the parts diagram.

I can find the boot that I have on the net but not in any parts diagram that I can find. Is it possible I have an "early" model and they made changes? Would researching the serial number help? Thoughts from the hive?

 

[dall]

pictures of your saw would help

 

[MS290man]

Here are pics

 

[MS290man]

New piston

 

[MS290man]

old piston

 

[MS290man]

The bar code label states that it is part number 1141-011-3041, MS271-Z .325 spur chainsaw

Can't find any info on a MS271-Z....

 

[big t double]

you actually have the newer version. whatever parts diagram you looked at probably hadn't been updated yet. the change happened at serial number 297527702. you need piston 1141 030 2003. the piston you ordered is a 1141 030 2012. ms271-z just means you have a fire safe mufflers. all saws that come to the US have fire safe mufflers and are labled with a "z".

 

[MS290man]

That's what I needed! Thanks!

 

[big t double]

no problem....Chicago huh...right in the city?

 

[MS290man]

no problem....Chicago huh...right in the city?

Western suburbs.

 

[big t double]

order from russos or ralph helm? those are the only two dealers I know out your way....hope they take the old one back.

 

[MS290man]

Ordered the right one from Carol Stream Lawn and Power; should have it next week. Bought the other one off eBay; no worries, it'll go in the spares box.