Now you can do a test. Run one at a time until it quits, add times together. Then run saws alternating to see what procedure makes for longer saw life. This maybe a long drawn out test.
One of them has a lower exhaust, didn’t touch the intake floor to maximize case compression and sloped upper transfer roof with the exhaust side higher than intake. Has a smooth broad powerband and is forgiving of a little too aggressive chain or a chain that’s a tad dulled. The other one I raised the exhaust a bit (good curve to the roof though), lowered the intake floor and flattened the roof of the upper transfers so they aim straighter across (I did not raise them though). I’d say it makes a tad more peak hp/torque than the other one, but the power band isn’t as broad. Rpm in the cut is similar between the two and cut times aren’t that much different.
3120 or K saw fuel filter ?
No. It’s for keeping spitback out of the stratos. The spitback just hits the back wall of the filter holder and goes into the stratos without it in there. The saw seems to gain some torque after this mod without any negatives other than the difficulty of grinding it out. I was actually inspired by other strato saws that have no spitback guard to keep spitback out of the stratos. It seems like it is only done for emissions is my guess.
