What do you think of this piston

[grenadier]

This is a MS200t that wont start is getting fresh fuel and a spark i reckon the pistons to far gone to bother to much with it.

 

Opinions please

[Ian C]

Yep, that looks knackered to me, pot and piston time or ebay as a "not sure whats wrong with it" saw:sneaky2:

[Mark James]

Yep, that looks knackered to me, pot and piston time or ebay as a "not sure whats wrong with it" saw:sneaky2:

 

I would go with the latter as stihl prices on the bay are just nuts, seems like paypal makes people think they have money to burn.

[Mesterh]

Its a pity we cant get hold of copy cylinders for the ms200T like you can for most other Stihl's.

 

Spare parts on ebay unless its a minter of a saw worth spending a few quid on.

[grenadier]

Probably just keep it for rogueing parts off.

 

thanks for the verdicts

[spudulike]

That is FUBARed, I would strongly recommend pressure checking the engine when puting the new parts on as you may have an air leak that caused this damage. It is more likely that it was run with old fuel or very old mix but the carb boot can crack and cause this sort of issue.

 

It is a shame you are not more local as I may be able to salvage the cylinder.

 

Spud

[grenadier]

funny enough she quit not long after going back to work after a 2 week lay off over christmasdidnt think the mix would have deteriorate in 2 weeks but will have to watch that in future on all saws. She had 3 hard years under her belt anyway

[spudulike]

2 week old fuel is fine, 4 weeks is ok, 6 weeks a bit risky and 8 weeks suspect. The petrol breaks the oil down over a period of time, hearing the fuel is two weeks old worries me and unless the mix was messed up would check the boot - a visual should do it and the crank seals. If either of these are bad, your idle speed will increase and be variable plus the saw will seize again.

 

Do the full job........ most saws seize through straight mix, old mix, poor carb adjustment and air leaks.

 

Spud

[roseyweb]

How do you pressure test a machine?

 

Have you thought of cheap non original parts

 

Garden machinery spare parts - Garden & Hire Spares

 

I've just put a new pot and piston in my 357 is running good do far and 80£ compared to the 250 husky one

[spudulike]

Pressure check - block the exhaust port, the inlet port and impulse line and then use a specialised plug with a suitable valve and gauge and pump up the crankcase to 7-9psi to ensure it holds pressure, you can also plug the plug hole and pressurise through the impulse line.

It should hold pressure for 10 minutes.

 

I have never used non OEM cylinders but they are probably worth a go if the saw is worth between £100 and £300, on a pro saw that will see lots of use worth £500 + then OEM may be best.

 

Spud