Stihl MS150TC...is 90PSI compression OK?

[BobbyDee]

Can any tell me whether engine compression of 90psi is poor for the Stihl MS150TC please? That figure seems low to me but it's a tiny teeny engine so it may be fine. I searched online but can't get any joy. I'm just trying to work out whether it's worth doing a makeover on my 10 year old one, which is still going reasonably well but definitely showing its age, or to get a shiny new replacement, probably the Echo CS2511 however they cost a fair bit more than the price of some new bits for the Stihl.

[Stubby]

2 minutes ago, BobbyDee said:

Can any tell me whether engine compression of 90psi is poor for the Stihl MS150TC please? That figure seems low to me but it's a tiny teeny engine so it may be fine. I searched online but can't get any joy. I'm just trying to work out whether it's worth doing a makeover on my 10 year old one, which is still going reasonably well but definitely showing its age, or to get a shiny new replacement, probably the Echo CS2511 however they cost a fair bit more than the price of some new bits for the Stihl.

It is very low but did you test it on a compression tester for a car ? If you did it will read low .

[Joe Newton]

15 minutes ago, BobbyDee said:

Can any tell me whether engine compression of 90psi is poor for the Stihl MS150TC please? That figure seems low to me but it's a tiny teeny engine so it may be fine. I searched online but can't get any joy. I'm just trying to work out whether it's worth doing a makeover on my 10 year old one, which is still going reasonably well but definitely showing its age, or to get a shiny new replacement, probably the Echo CS2511 however they cost a fair bit more than the price of some new bits for the Stihl.

I think after ten years you can probably retire it. It's earned its money.

[BobbyDee]

26 minutes ago, Stubby said:

It is very low but did you test it on a compression tester for a car ? If you did it will read low .

 

[BobbyDee]

Not sure if the tester is specific for cars but it does have a connector with the correct thread. Tested when engine cold so I'll try again with a hot test.

[spudulike]

It will be even less. What brand is this tester? 

10 years abuse is good for any saw, invest in a new one and keep the old one as a backup.

With 90psi compression, the saw wouldn't run.

[Dan Maynard]

L&S list cylinder and piston at £41, seems like buying a compression tester bit of a waste you might as well just treat it to a new cylinder every ten years whether it needs it or not.

 

If the rest of the saws ok of course...

[BobbyDee]

13 hours ago, spudulike said:

It will be even less. What brand is this tester? 

10 years abuse is good for any saw, invest in a new one and keep the old one as a backup.

With 90psi compression, the saw wouldn't run.

The tester is a no-name variety but does give what appear to be reasonably accurate results on my other saws, very close to the figures quoted in the service manuals.

[BobbyDee]

2 hours ago, Dan Maynard said:

L&S list cylinder and piston at £41, seems like buying a compression tester bit of a waste you might as well just treat it to a new cylinder every ten years whether it needs it or not.

 

If the rest of the saws ok of course...

Fair comment. I note there seems to be 2 versions of the kit you mentioned, the other being priced at £154.80 + VAT, both with the same part number. Quite a difference.

[ChrisNewport]

Mine failed on the crankcase mounting holes wearing oval and the engine cocking over and the flywheel rubbing against fuel and oil tank. Common problem by all accounts if not caught in time they wear through, so much so that Stihl do the crankcase kit at a reasonable price. Whilst it was apart i put on a new P+C as i thought they had made a mistake in the price when i was looking at it. Its pretty much had a new short motor for just over £100 which i thought was well worth doing.