Stihl 088

[CCB]

Hi, got the saw back tonight,stripped it down, when i took the top casing off the saw to take the head off, all four bolts were slack? not totally out but enough to cause slight movement! thought i better rule out what was staring me in the face, i tightened them up put the carb back on etc pulled the cord and it started!! it seems to run ok?

 

Next Question, looking into the piston from the exhaust side, the piston has a rough almost serrated edge along the top? like a saw blade? surely this type of damage would stop the saw running correctly? is this a common sight on an older saw? what causes this type of damage? i have never seen this happen to any of my own saws?

 

if the saw was mine i think i would replace the piston, at this stage, my friend doesnt seem to bothered? what do you guys think?

[agg221]

I think what you've got is an air leak into the crankcase, through the base of the pot where the bolts were loose. This has been causing the saw to run lean, resulting in damage to the piston on the exhaust side. The bigger saws tend to keep running with some damage to the piston in my experience, but there will be considerable loss of power as there will be leakage around the piston.

 

Far more significantly, there will probably be some aluminium transfer to the pot, but if it's running this may be minor at this stage. A non-OEM piston can be had for this model, but not the pot. I would therefore very strongly recommend having the pot off now, getting it properly cleaned up, checking what state the bottom gasket is in (likely to not be great if it's been running loose, and may well still leak) and then fitting a new gasket and piston. This will cost less than £30 all in, rather than several hundred if he wrecks the pot!

 

Alec

[spudulike]

The top edge of the piston should be machined with a bit of carbon on the top but not rough looking -take a picture of it as it sounds like the saw has seized at some time and this can cause a rough edge.

 

I guess someone may have put something in the exhaust port to stop the piston to remove the clutch - a real bad idea and this may have mullered the edge:confused1:

[treequip]

I think what you've got is an air leak into the crankcase, through the base of the pot where the bolts were loose. This has been causing the saw to run lean, resulting in damage to the piston on the exhaust side. The bigger saws tend to keep running with some damage to the piston in my experience, but there will be considerable loss of power as there will be leakage around the piston.

 

Far more significantly, there will probably be some aluminium transfer to the pot, but if it's running this may be minor at this stage. A non-OEM piston can be had for this model, but not the pot. I would therefore very strongly recommend having the pot off now, getting it properly cleaned up, checking what state the bottom gasket is in (likely to not be great if it's been running loose, and may well still leak) and then fitting a new gasket and piston. This will cost less than £30 all in, rather than several hundred if he wrecks the pot!

 

 

 

 

Alec

 

Or its had god knows what wrong with it and they chucked it back together and did an ebay "spares or repairs" special on it

[CCB]

Going to try and convince him to go for a new piston,gaskets etc, its a very clean saw, definatley worth it! it will probably be me who will do the work to it, i will take some pics of it when i start and post them on, chances are i'l need some more advice about it again? thanks for taking the time to reply, the advice is appreciated!!

Cheers

Chris

[agg221]

Or its had god knows what wrong with it and they chucked it back together and did an ebay "spares or repairs" special on it

 

Yes, this is always possible, but I'd be surprised if it ran at all in that case

 

Alec

[Rich2484]

I would go with spuds description of why the damage is there. Someone using the exhaust as a piston stop. But if they knew what they were doing they would have done it properly in the first place.

 

The base gasket would need replacing. The pot will need inspecting before some serious damage is done to it. As its been said they are hard to come by unless you want to spend mega money getting another. Most of the time it's not viable to buy another pot and just get another saw.

 

Looks like meteor don't do the 088 but Is worth asking. Might just not be listed.

 

If the pot can be cleaned its worth doing. As IMO the 088 is a monster and much better than the 880 buts that's just my opinion.