I might not go deep into engineering specs, beyond the basics however I have two 076 AV Stihl's that I picked up in a barn find when buying a band saw. The seller bought the house and things came with it.
I replaced both Pistons and heads on both of them since I got them both for 300 dollars along with a sperber mill. I used them for Chainsaw milling which is hard on any saw.
I replaced them from
SawAgain LLC .
Two years spacing between the first one that went and the second. I could not find OEM for the saw, but the engine is still sold by Stilh from my understanding as a concrete saw. The first time I just bought it and the second time spoke with the guy at SawAgain and decided it was my best option. Both saws are working great and as stated one for almost 2 years.
| SAS0569 | Cross Performance Stihl 075 076 Ts 760 Nikasil Plated Cylinder Kit Replaces Oem 1111 020 1206 |
Stihl, where I am, will not even work on the older saws. Had a certified person at ACE but after one month of waiting for a repair on the compression button, I abandoned that and just decided to repair it myself. (I was a licensed aircraft mechanic but moved on to other things a long time ago. So not without knowledge) The first saw had an issue with vibration but did not know that at first. After some time it refused to start I checked it out, and had a loose exhaust and poor compression. I noted the loose exhaust but did not add much consequence till later. I replaced just the piston and rings at first and had the head honed by the Mech friend. I used it but not great on power, and replaced the piston and head with the help of a buddy with years of experience as a mechanic. After we fixed it and with a lot more experience I noticed the vibration issues and replaced all the mounts, I also changed out the exhaust gasket with a metal type from Napa that you cut out, and came in a large sheet. I could not locate an OEM gasket or any specific one at the time. After solving the mounts and also chainsaw sharpening changes so that little vibration occurs I have not had any other issue with the saw. It powers through.
The second saw froze during a really hot 118-degree day on a fool's errand sawing a bunch of logs I was dropping off for free that were unusable for me at a veteran house from craigslist when I posted free pine logs and found he was in his 80 with no way to cut it up. Wasn't the best, and did not necessarily properly measure the oil I was using, as had a McCoullgh and the 076, and a cheapy saw all with different mixture ratios. It heated and froze. It was done for the day. I managed to get it to unfreeze later with transmission fluid, but it looked like your cylinder. I checked the compression, and it looked like it had compression but just would not start or even attempt to fire, and numerous attempts troubleshooting.
The exhaust port looked like yours, and the rings were just as skewed as the piston you had in the picture. It tore up the inside. We opened it up and I did some research but My Mechanic buddy, was in no way that the cylinder was going to be repaired as that ring gouged enough out of the exhaust port that it was not going to be honed. I looked at it convinced I could, but hell he has far more experience than I. It was the original head which I still have. Still a bit stubborn.
I Replaced the piston, rings, and head. Was able to find all the gaskets this time, and had a shop rebuild the carbs for me, as after two tries purchasing on eBay the parts were wrong. I did barter for some slabs at the lawn shop and they rebuilt both and I bought a whole bunch of other stuff.
As a note both times the piston had to be filed where the wrist pin slides through. This may be the coating but he did it on the first one-two years ago without informing me but I saw him do it. I had not had as much experience as I do now with the number of saws that I now own. We did it on the second after discussion.
The Saw fired up and the power is amazing so I am pleased. I am not trying to sell it, with OEM or not. I just bought a 660 as another saw and the power on the 076 is far above it after the rebuild.
There may be differences in OEM, but 2 cycle engines are problematic at best, compared to the dependability of 4 cycle engines. In all the years of schooling, I had on engineering and Aircraft systems at Northrop University that was certainly drummed in.
These saws are older and made at the time of Lead gasoline which was used to stop the knocking and ensure assist ignition but was deadly. The gaskets are affected even today by the gas we buy today so there is a lot to take into account. What I do know is the power is great and I am sawing again.
