Counter clockwise? It was basically there, I had maybe a 1/4 turn to get to the stop turning counter clockwise.
That will add fuel. Better to start at full rich and and adjust a bit leaner as you go. What seems too rich at no load will make power in the cut. Remember that the carb will lean out as RPMS drop under load but you are still holding the throttle wide open.
If the tabs/stops are still on the screws/jets? Then full in and full out are not full in and full out.
When I bought my 660, with a 28" bar, I didn't have any bogging issues and it seemed powerful. The factory WOT was as 12440. I later added a factory DP muffler and set it at 12880 which seemed to be 4-stroking well. After joining a few chainsaw sites I decided to have it ported. After it was ported it was a significant increase in power. Now, with 93 non-E fuel at 32:1, it 4-strokes well at 13,900 rpms+ but I set it slightly less. The guy who ported my 660 said it came with an excellent jug. The saw was later put on a dyno to determine max HP. The guy with the dyno also put his stock 660 on the dyno to determine factory HP. The factory 660 HP was not to factory specs and is only around 0.5 HP more than a stock 372 if the Husky HP specs are correct. Stock 660 HP only showed 5.7HP (factory specs says 7.1) and the 372 stock HP, factory specs, shows 5.3HP. That might be the reason you're not seeing much difference. Adding a DP muffler increased the HP over 0.7HP but after porting it increased the HP to 8. Here's the dyno chart to show you what I mean.
Ron, I've seen that graph before and it's very impressive! The big question is; how thirsty is she now? I hear ported 66's like a lot of fuel.
They are thirsty stock. They need more gatorade the more port work was done. Just depends who did the work and how aggressive they went with the transfers and exhaust. Too much is not always good. Mine isn't exotic, but its built to work, not cut 12x12's all day. set fat for milling, it used a tank and a half per cut on the mill doing a 28" oak by 10 feet long. not super impressive but, listen to the R's felling this Pin oak. It doesn't drop rpm much at all. I think it was a 32" bar, but it was a 3-4 years ago and I think I said a 28" maple in the video. It was definitely oak and I had to make a cut from each side as the stump was 35-36". No piston machining, no squish, just decent porting, some intake duration added, ports widened and base gasket delete from some increased compression. it runs much better than a stocker, and can literally be stood on without it falling on its face with a long bar, and is still fairly fuel efficient for what it is. It carries the R's much better in bigger cuts than a stocker. It's not a slouch at a gtg with a race chain, but it isn't the fastest thing in the world by any means. this saw has been together since 2008ish, and is used for large stuff only, stumps, milling, and just plain huge nasty wood that most people don't want to mess with. even when stock it ran good, but wouldn't compare to a 372 in anything over 24" it would walk away from a 372, bad. shorter bars, or 20" wood, you'd be hard pressed to tell on a stock 660 with a dual port and a 372, but where they shine is torque in larger wood with larger bars. It still shouldn't bog in 20-24" wood. Don't critique the technique too much, as I was leary of all the dead limbs up top. A coworker got paralyzed from dead branches coming down on his head without any kind of hard hat, not looking up watching movement, and i had sold all my climbing gear long before I dropped this tree. I was cutting alone, so I was a little uneasy just because of the situation, and the reason I got out of the way at the first sight of movement instead of powering through the cut. It had to land where it did, or it would have gotten hung up in another large oak where the phone was , or the garage. there wasn't much room for error, even though it looks like there is tons of space from the video. I was more comfortable dropping the maple 3 feet off my house that had a 18" stem hanging over the roof.
Intake will effect the fuel usage some also. Longer durations run a little better at altitude also. I was using a ported 390 milling and it was using a tank every half cut in 22" wide cherry.
Took the saw back on the hill to do another test cut. Same result, after the tune up. I've got a friend who's coworker has a 660 and a 36" bar for it ( i think) and I'm going to run mine down there one day and slap that bar on it and try it. Everyone seems to say a 20" bar isn't a fair test/comparison for the 660, but i don't see how. If it bogs on a 20, how's it suppose to run anything bigger....
You should be use the dogs pretty hard on a 660 with a 20'' bar. I thought you found it was low on compression?
