Upgrade MS290 to MS390 or just leave it & flip.

[WetBehindtheEar]

Hey all - been a while.

I picked up a seized MS 290 with intentions of putting a 390 piston & cylinder on it. I've done one before & have been happy with the results and I was thinking this would be a great project for my 10 year old son to work on.

I got the saw home & was in the process of taking the clutch off & the saw un-seized revealing a VERY good condition piston & cylinder.

It turns out the bearings were completely frozen up until my impact wrench loosened them up.

Further disassembly showed water in the bottom of the crankcase and the seal was not complete around the entire clamshell.

Prior owner guy claimed his saw stopped running for some reason & then couldn't get it to restart... then when he tried to start it a month later it wouldn't pull over.

Dude probably dropped it in the lake cleaning up his waterfront property...

So what I've got is:
A completely disassembled MS 290 that needs bearings. The OEM piston & cylinder are pristine.

Do I:
a: Replace all bearings & seals, put it back together & re-sell it

b: put on an aftermarket piston & cylinder (not bought yet), do the muffler mod & then re-sell it for more

 

[HarleyT]

You will need to decide if the rod bearings are good or not.

 

[Mad Professor]

I'd find a 034/036 that needs some love.

 

[jltrent]

As said check rod bearing if okay new quality bearings and oil seals and put back together. An 8cc difference helps, but is not a world of difference.

 

[berrnard]

B should not sell more than oem unless you ebay it.
Save oem for another build and use the am 390 parts


Sent from my iPhone using Tapatalk

 

[Ketchup]

From a sales perspective, most 290 buyers want a shiny, stock, OEM saw. They like 290
because it’s a known depndable runner. It may actually be harder to sell it with performance “upgrades”.

I would rebuild it OEM and have recipts to prove it. Since you already have the upgraded version, no need to keep this one.

Better yet, make your son do it and he can keep the profit when it sells.

 

[WetBehindtheEar]

I'd find a 034/036 that needs some love.

Interesting idea but not too many of those hanging around on CL these days...

Thanks for the input, all.
If the rod/piston pin bearing looks good, I'll have the boy help put new bearings on, seal it up & have him sell it.

TB