!MS 362 Mishap!

[Luke Kershaw]

Hi wonder if anyone can shed some light into a situation I've got myself into.

 

The problem is I used a piston stop to take off the clutch assembley and snapped the one end off andit broke into the engine itself but managed to retrieve the large section of it and gave it a rattle to see if any more fragments were left inside. It seems like there was a faint ting going on in there.

 

Next step I tried to start the brute up and nothing.

 

Just would like to know if it's advisable to take out the engine and check to see if any piston damage is going on in there. Would anyone have any hints on removing the engine as well?

 

Please please I love this saw!!

[Mike Hill]

What was the Piston Stop made from?

[Mick Stockbridge]

Nylon I'd imagine, one of those black double headed things.

 

Done the same myself in the past, difference is this one started and I used the saw until it died a natural death. God knows what happened to the bit that broke off.

[Mike Hill]

If its a plastic bit in the Bore.Pull the cord untill the Piston is at the Bottom,fill the Bore with Fuel,then pull smartly on the Cord.

 

Out comes the peice.

[geoff]

I would get the exhaust off,make sure its not in there & with the piston at bdc,check out the insides with the plug out & a torch shone down it,also check the piston skirt & rings in case the stop was 'guilotined' in the exhaust port,if all is well get it back together & try to start it again.

[Rich2484]

Just out of curiosity and to eliminate human error, have you double checked that everything you took apart or off the saw has been put back on, like the usual tests of getting spark and fuel.

 

Just going through the obvious things first, not saying anyone is thick or you are incompatant in any way shape or form.

[Arctostaphylos uva-ursi]

I have seen piston heads broken with the metal stops! Have you got any compression?

I have broken one of those dreadful plastic ones off in one of my saws. I just tipped the saw upside down and shook it until I could see the plastic in the plug hole. Then using a piece of wire to guide it out I giggled it about until it finally dropped out. Now I only ever use starter cord as a piston stop.

 

Hope you get it sorted!

[spudulike]

Mmmm, not the first time and won't be the last, if you have used one of those screw in metal piston stops, you are a bad man. They are meant for use with older saws where they push down vertically on the piston crown - I use a long sparkplug with the end ground off - larger contact area.

 

If it is the plastic stop that you have sheared the end off then the saw will normally run OK, I use thes on most saws now but make sure the end is up against the inner wall of the cylinder above the exhaust port.

 

Another good option is recoil rope but bring the cylinder up to above the exhaust port before putting it in.

 

If the saw isn't starting then you may have cracked the crown of the piston, if fragments of metal have got in to the crankcase etc then it would make the engine difficult to turn over. It is possible that you have had some metal enter the transfer or inlet/exhaust port and it has scored or damaged the rings/piston.

 

Personally I would pull off the top end and take a look at the inside, you may be able to inspect from removing th muffler and looking through the exhaust port or down the spark plug hole.

 

A compression check will help - the saw below was at 120psi, healthy is 150!!

 

Here is an image that will show you the damage stops can do -

[Rich2484]

Sorry to be a pain but how do you use starter cord as piston stop?

[spudulike]

Sorry to be a pain but how do you use starter cord as piston stop?

 

:001_rolleyes:

You turn the engine clockwise until the piston covers the exhaust port, get a piece of recoil rope and stuff it down the plug hole until you can get no more down there - long nose pliers help and you then turn the engine clockwise until the rope compresses and stops the engine turning over.

 

It provides a good even pressure on the piston and works well on larger engines where the clutch is pretty locked on.