462 Compression

[TX_Welder]

Anybody ever put a compression gauge on a stock 462? I put one on mine this morning out of curiosity just to see what it was and I was kind of surprised. It only blew 118 psi and it seemed harder to pull over until it got to peak compression then it seemed to ease up. Strange feeling. I did check to make sure the decomp wasn't pushed in.

I'm 43' in elevation and it was 43° here this morning.

 

[huskyboy]

Those take a small plug that needs a adapter for compression tester right? Guys say they get iffy readings with those.

 

[TX_Welder]

Yeah it was the smallest adapter that I have with my set. A lot of my four wheelers and dirt bikes have the same size/thread pitch. never heard of getting weird readings with the small adapter.

 

[angelo c]

Hows it run ?
Reason to suspect "low" performance ?
Have it checked if it's under warrenty by a stihl certified shop and keep ALL supporting documentation like a lawyer. Names, dates signatures.

 

[TX_Welder]

Runs like a scalded dog, I was just curious to see what it was. It felt like alot more than that.

I got the saw used so there's no warranty that I'm aware of. I popped the front of the muffler off and looked inside and all looked good.

 

[Manofstihl661]

The adapter will give you a low reading unless the valve is at the end of it. Or something along those sorts. Most the adapter ones give low readings

 

[qurotro]

I don't have the adapter for that small plug. But by holding the start rope, my PHO would hold more than 10s before dropping.

 

[drf256]

The adapter will give you a low reading unless the valve is at the end of it. Or something along those sorts. Most the adapter ones give low readings

Bingo

The combustion chambers are small, and unless you have a valve at the very tip of the adapter, the adapter volume will be added to the chamber volume. This will give you a falsely low reading.

 

[thesawincanada]

Just for discussion I got an ms362 from one of my customers who own a tree service saw has tons of hours did a compression test was 170psi. Saw runs like a ravished dog. I end up buying it off of him. He replaces his saw fleet every 4 years so I bought this saw and an ms260.

 

[blsnelling]

As already mentioned, you will not get a correct reading issuing an adapter.

 

[TX_Welder]

Here's a pic of my setup. Same setup gave me a 150 psi reading on a husky 350 I just put together. I cut .015 off the base on that saw, s quish came in at .022

That's why I was surprised I only got 120 out of the 462.

 

[Duce]

No valve at end of adapter is reason for low compression. That adapter adds cylinder volume.

 

[dustinwilt68]

Not sure of the compression, but the one I ran @farmer steve owns, ran very nice for a stock saw.

 

[blsnelling]

Here's a pic of my setup. Same setup gave me a 150 psi reading on a husky 350 I just put together. I cut .015 off the base on that saw, sView attachment 207161 quish came in at .022

That's why I was surprised I only got 120 out of the 462.

That setup will give a false low reading. The volume of the adapter adds to the volume of the combustion chamber to make it read significantly lower than the actual compression. There MUST be a Schrader valve at the very tip that is screwed into the cylinder.

 

[TX_Welder]

Okay makes sense. when I checked the little husky I didnt have to use an adapter.