Stihl 056 compression

[spudulike]

Got a Stihl 056 on the bench, first time for one of these. Compression is measured at 130psi on two gauges, one is very sensitive and the other less so, if the bore or piston is a bit worn, the less sensitive one usually reads 20-30psi lower than the other

I am getting 130psi on both gauges on a cold engine that is fueled so the bore isn't dry - is this about right on this type of saw - I know some of the more modern ones run at 150 -175psi.

Anyone got any experience - if this is fine I won't tear down the top end but if the opinion is that it is low, then I will tear it down and take a look!

Cheers from the UK in advance

 

[OREGONLOGGER]

Got a Stihl 056 on the bench, first time for one of these. Compression is measured at 130psi on two gauges, one is very sensitive and the other less so, if the bore or piston is a bit worn, the less sensitive one usually reads 20-30psi lower than the other

I am getting 130psi on both gauges on a cold engine that is fueled so the bore isn't dry - is this about right on this type of saw - I know some of the more modern ones run at 150 -175psi.

Anyone got any experience - if this is fine I won't tear down the top end but if the opinion is that it is low, then I will tear it down and take a look!

Cheers from the UK in advance

130psi should run fine it's when the psi gets below 100 on those 056's in any model I would hone and put a set of rings in and run a couple of tanks to set the rings as it should bring the psi back to 180+. Jug gaskets are rare to find so if you take her apart be carefull as to save the gasket. I use iron oxide sandpaper to hone the inside of the jug just 10 swipes in circles does the job and clean the jug very well. With new rings and this app will keep you're 056 running for a long time....good luck

 

[maico490]

Hi Spud,
I've got a couple of non Super 056 saws. The first I bought back in the 90s and is getting worn but still has 140psi. The other is a very early one with the Fairbanks Morse starter that I bought for spares off ebay but turned out to be too good to strip. A few bits and pieces and a Episan piston from the Greek guy and it now has 195psi. You really have to mean it when you start it or it will try and have your arm off.

Mike

 

[spudulike]

Hi Spud,
I've got a couple of non Super 056 saws. The first I bought back in the 90s and is getting worn but still has 140psi. The other is a very early one with the Fairbanks Morse starter that I bought for spares off ebay but turned out to be too good to strip. A few bits and pieces and a Episan piston from the Greek guy and it now has 195psi. You really have to mean it when you start it or it will try and have your arm off.

Mike

You stalking me:msp_biggrin: Thanks, sounds like this one is a bit lacking, think the top end will have to be pulled and a look at the piston condition - was trying to avoid it but it sounds like it needs a look at - it pulls over a bit easy for my liking - was expecting it to rip my arm off but pulls over a bit too easy.

Thanks
Steve

 

[dom1971]

[Howdy, to hone a cylinder can you do it like this guy ?. I have a 056 that feels like it has lots of compression but won't start even with a squirt of fuel in the carb or into the spark plug hole. took to dealer, waiting on diagnosis. Not too costly but will help save my sanity

 

[powerking]

[Howdy, to hone a cylinder can you do it like this guy ?. I have a 056 that feels like it has lots of compression but won't start even with a squirt of fuel in the carb or into the spark plug hole. took to dealer, waiting on diagnosis. Not too costly but will help save my sanity

most likely bad ignition....These Bosch setups are known to go bad.....There is a workaround for them though

 

[dom1971]

thanks for your reply, I was able to see a blue dip spark, timing is right with new key and at this point could it be a scored piston, would that keep a high compression
? Gave it to Stihl to diagnose last week, they Stihl haven't called me back, ha

 

[powerking]

i had my super give me nice blue spark too, bu tit would not even pop........i tried a differnt coil and it fired no problems, then i had to modify it because it kept shutting down when hot

 

[dom1971]

thanks for the reply, I will try that, many parts saws. is that the Greenie wire, how to modify ?

 

[Mad Professor]

When the bosch coils start going bad they will run fine until they start to warm up then cut out like they run out of fuel.

Foggysails coil fix will make them run again.

If you are worried about compression have a look at piston/cyl through exhaust. If things are not too worn, a set of rings will help.

 

[dom1971]

When the bosch coils start going bad they will run fine until they start to warm up then cut out like they run out of fuel.

Foggysails coil fix will make them run again.

If you are worried about compression have a look at piston/cyl through exhaust. If things are not too worn, a set of rings will help.

Thanks, did someone ever make video how to fix that greenie wire ?