MS280 Crank Case Difference

[M2theB]

i may be SOL here but I’ll ask.

Replacing the crank case on this saw because in working on it this summer I broke these really thin air dams. I built it anyway and it ran with air leak. I tore it down and built again paying extra attention to sealing jug to the case. That worked better until it warmed up and then it ran like it had an air leak.

I was able to get a used case and when I started working on the saw I notice the case I got only came with one bar stud and the tensioner configuration was different. New to me case below.


The case to be replaced is below. So far the only differences I can see are the bar studs and the tensioner. Comparing the two, I think I have a chance at mounting the old studs in the new case. Where it looks like I’m “f”worded is on the tensioner.

Below are the egg shell air dams on the new to me case. (I have pictures somewhere of the broken ones on the almost running saw)

The questions are;

Did I really get a 280 case? ( I did ask for a 270 or 280 because I read they were interchangeable)

And can I make this case work with a 280?

 

[DND 9000]

Did I really get a 280 case?

Yes I think so, but different versions. The case with 2 bar studs is used on MS 270, 270-Z, 280, 280-Z and the one with only one bar stud is for the MS 270, 280 C-B versions. As you`ve already mentioned the thing with the chain tensioner, there may be more differences and I`m not sure if you can combine these different case halves.

 

[M2theB]

Yes I think so, but different versions. The case with 2 bar studs is used on MS 270, 270-Z, 280, 280-Z and the one with only one bar stud is for the MS 270, 280 C-B versions. As you`ve already mentioned the thing with the chain tensioner, there may be more differences and I`m not sure if you can combine these different case halves.

I think the clutch cover may become an issue.
I’d like to try to re arrange the studs, maybe get the tensioner for that case and keep moving forward.

Thanks for laying it out @DND 9000