# stihl ms 290 chainsaw



## ccrider966 (Jul 8, 2006)

I need to replace a scuffed piston and cylinder in my ms 290 chainsaw. I see kits on ebay with all the parts to do this. Most are reproduction parts and I wonder if anybody here can vouch for their quality? I think everything else is in good shape but the piston is very badly scuffed as viewed through the muffler opening. 
Has anybody here replaced the piston and cylinder in this saw and what tips can you provide?? I have a service manual cd and should be able to do the work myself.


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## Don L (Jul 14, 2012)

I would recommend checking the price of genuine Stihl parts before buying aftermarket.If the difference is'nt too great go with OEM.Most of the aftermarket parts I've seen work,just do'nt fit as well and are harder to make work.
Stilh builds products to be easily serviced,the only thing I can think of is that one of the bar studs screws into the crankcase and must be removed.You can jam two bar nuts together and use a wrench to remove the stud.
I think the MS310 is the same except for the piston and cylinder size,if you want more power this might be something to research before buying parts.I've never tried this swap but I really like the extra power of the MS310 with the same weight as MS290.
Carb tuning is the only issue I can think of with this swap,I certainly can't recommend removing the limiter caps on the carb,if you do it is much easier to do it before you reinstall the carb.


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## billsmowers (Mar 21, 2008)

ccrider966 said:


> I need to replace a scuffed piston and cylinder in my ms 290 chainsaw. I see kits on ebay with all the parts to do this. Most are reproduction parts and I wonder if anybody here can vouch for their quality? I think everything else is in good shape but the piston is very badly scuffed as viewed through the muffler opening.
> Has anybody here replaced the piston and cylinder in this saw and what tips can you provide?? I have a service manual cd and should be able to do the work myself.


before you buy a piston kit you need to find why the piston got screwed in the first case eg lack of lube, lean carb settings, air leak etc. or you will be back to square one and need another kit some aftermarket kits are ok just make shore it has a nickoseal coating to the cylinder
hope this helps

bill


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## ccrider966 (Jul 8, 2006)

Thanks, I found the note to remove the bar stud in the service disk I have. The cost is considerably different, like $100 difference! So I will likely use the aftermarket parts advertised on Ebay from a seller with lots of parts sold with good references.


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## ccrider966 (Jul 8, 2006)

Thanks, I bought the saw as stuck and do not know cause but I suspect it was improper mixture of fuel. I will try not to lean out the mixture if I ever get it back together!
I never heard of niko seal coating, what is that and how can I check other than asking seller on Ebay of the piston and cylinder?


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## Don L (Jul 14, 2012)

Just another thought,be sure to check the bearings for roughness before ordering parts.
For a hundred dollars less I would use aftermarket parts too.


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## paulr44 (Oct 14, 2008)

billsmowers said:


> before you buy a piston kit you need to find why the piston got screwed in the first case eg lack of lube, lean carb settings, air leak etc. or you will be back to square one and need another kit some aftermarket kits are ok just make shore it has a nickoseal coating to the cylinder
> hope this helps
> 
> bill


VERY VERY TRUE. IF the carburetor is a problem, or a vacuum leak exists the saw will probably just fail again in a short period.

A crankcase pressure/vacuum test should always be done in these circumstances, and EVEN THEN, the carburetor will be an UNKNOWN until you can run it (unless you have a carburetor flow-bench (mucho bucks!!)).

We NEVER provide an estimate for a piston/cylinder job without informing the customer the CARB. may be at fault, is currently unknown, and will cost $XXX MORE if it is a problem after the rebuild.

Had a very large saw do just that to me...the carb. worked fine for after the piston/cyl replacement, but apparently when hot and under load it leaned out...had to replace the pist/cyl for free but the LONGTIME customer was understanding and paid for carb (no labor).

BILL'S warning is very real and accurate...
Paul


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