best bar length for 7900

[ocean4surfing]

OK, I'll check that out. I've watched most of the 101 videos on YouTube, but I know there is always more to learn. I guess one last question and then I'll just post results as I make changes to try and get this figured out.

All the YouTube videos I've seen fast-forward the actually milling part, so there's no way to know how long it took them. How long should it take an 80ish CC chainsaw to chew through one 10' x 24" slab? I am not looking to exactly match your time time metric, but it seems like my 30-45 minute per slab number is excessively high, and I'd like to know what the ballpark should be. If it does indeed take 30-45 minutes to mill a slab, I think I may consider getting a smaller end Bandsaw mill.

 

[Dph1256]

I dont have experience milling but i have heard people here say about a tank of gas per decent sized slab.

 

[foeke]

That's not a big slab. I would guess 5 to 10 minutes or so.
Note that the hardness of the wood isn't the only factor. It's also the toughness that makes it go slow. Poplar can be quite though.
And make sure you wedge it constantly.
But most important. If you used a normal chain, you didn't give it a real chance.
These are set up also for that guy with a crappy saw that thinks you can use a chainsaw onehanded and hold the branch with the other hand.

 

[foeke]

Oh yeah, 28" is the answer for the OP.
Bigger than that the saw is not balanced anymore. And I don't think the oiler handles the bigger bars.

 

[AUSSIE1]

Dust equals high rakers. Bring them down.....heaps. Youll be surprised by how much the rakers need to come down. What will happen is the saw will start to cut quicker. Bring them down more, the saw cuts quicker again. Keep bringing them down till you feel the saw start to bog down in the cut a little. This should be about right so from now on you dont have to force the saw to cut. Measure your raker depth for future setup.

 

[AUSSIE1]

Id say it will cut in half the time its taken to date.

Dont go buying bandsaws. Understand that thousands plus 1 have success with these so theres no reason why you cant. You need to research more and try more things. Ive only been milling for two weeks yet ive got it figured. You will too.

 

[foeke]

Totally right. Except for the don't buy a bandsaw.
There is a time and place for every saw.

 

[AUSSIE1]

Totally right. Except for the don't buy a bandsaw.
There is a time and place for every saw.

meaning dont replace your chainsaw mill for a bandsaw because you are having issues with it.

 

[toadman]

I can try filing down the rakkers some. Here are the pics of my current chain. Has your carb been tuned? Is there any difference between ea7900 and 7910?View attachment 837656View attachment 837657View attachment 837658View attachment 837659

what chain oil you using? looks like it's to thick & sticky.
I had that with stihl Bio oil, & tractor supply brand regular, when I started milling and tried to save a few $$$... major power suck, and made me doubt my husky 394's power for milling.
switched brands and she's flying through wood milling now. no other changes made in my case.

 

[toadman]

Another thing to check is make sure it's filed evenly sharp with even angles from side to side, with the rakers filed properly in regard to the tooth length, (with a proper raker gauge). if one side of the chain's cutters are off by a bit from the others, it will try and run one way or another and bind against the frame. doesn't take much... the tooth length doesn't mean anything on how straight it cuts, as long as they're all sharp and the raker's depth matches the teeth in my experience.

 

[ocean4surfing]

Thanks for all the replies. I got the new 28" bar in, but haven't yet put it on. I think there's an issue here that needs to be resolved. Based on what you all have said , it shouldn't matter. Makita supports the 32" bar. I went out to cut a 24" slab today and it took two tanks and 45 minutes to get through a 10' section. That's ridiculous. I made an observation and I want to run it by you guys. When the saw is almost out of gas is runs a lot better and doesn't seem to bog down. When it's full it runs like crap and doesn't seem like it's revving high enough. It also has trouble idling. For example, if I rev it and then let off completely, the saw will cut off. If I ease down really slow back to idle it will idle sometimes. It's kind of annoying that it has struggled to idle since I took it out of the box a few months ago. I'm not an expert, but does this mean it's running too rich? Seems like whoever adjusted the carb when I ordered it new might have not done it correctly. Let me know what you guys think? I'm ready to try to make an adjustment, but don't want to blow up my saw. I know a saw will rev high when its almost out of gas because it's too lean, but when I have like an 1/8 of a tank left the saw seems like it runs right. I usually try to turn off the saw when I know it's almost dry. I still plan to lower the rakkers like you guys suggested, but I think fixing the run problem is the real issue. In my opinion this saw should not bog with the size of wood I am cutting. My echo 620pw does not bog period and from what I'm told this Makita should kick my Echo's ass. Does it sound like it's running too rich? I'm running Husqvarna XP 50:1 mix (95 octane) and use Husqvarna premium bar oil.

 

[Andyshine77]

Ocean it sounds like you have multiple problems. Are you milling, or bucking logs? As it should not take but a couple of minutes to do that amount of bucking, even if the saw is tuned dog rich "which it sounds like" my guess is your chain is dull as could be. If milling, yes it's going to be slow going in a log that size, still shouldn't take more than ten fifteen minutes or so, and really you need a bigger saw to mill with IMHO.

Every saw needs to be tuned for the environment and fuel mix, factory settings are just a basic starting point, milling you do want it on the rich side and 50:1 is no good for milling run 32:1 or you will burn the saw up. Yes it sounds like it needs proper tuning, and it likely sounds better at the end of the tank of fuel because it's starting to run lean, and possibly closer to where it needs to be .

Some videos to get you started down the right path.

 

[ocean4surfing]

Ocean it sounds like you have multiple problems. Are you milling, or bucking logs? As it should not take but a couple of minutes to do that amount of bucking, even if the saw is tuned dog rich "which it sounds like" my guess is your chain is dull as could be. If milling, yes it's going to be slow going in a log that size, still shouldn't take more than ten fifteen minutes or so, and really you need a bigger saw to mill with IMHO.

Every saw needs to be tuned for the environment and fuel mix, factory settings are just a basic starting point, milling you do want it on the rich side and 50:1 is no good for milling run 32:1 or you will burn the saw up. Yes it sounds like it needs proper tuning, and it likely sounds better at the end of the tank of fuel because it's starting to run lean, and possibly closer to where it needs to be .

Some videos to get you started down the right path.

Thanks, I've watched a ton of videos. I'm blown away at how much of a hassle this is.

I'm milling. 24" is about the max I'll ever need to mill and most of what I will be milling will be much smaller. I haven't bucked a log with this saw at all. I use my other two saws for any bucking because they are lighter. I was milling with my cs-620pw and bought this 7900 hoping 20 more CCs would allow me the chew through slabs faster, but so far I've burned far more fuel and it's actually taking longer to cut through slabs. In terms of sharpness, I try and sharpen the chain every other slab, so right now the chain is tacky and sharp, but some suggested that I lower the rakkers. Thanks for the insight on the fuel mix. Didn't realize that I should use anything other than 50:1. I'm pretty easy on my saws. I usually let the saw and bar cool some every few feet through the slab.

I figured that out of the box brand new, the saw would be adjusted properly and idle. I didn't realize I would need to adjust anything. The manual seems to discourage making adjustments. My other two saws CS-490 and CS-620pw worked perfectly out of the box, but I'll give it a try.

If I can't get this thing to outperform my cs-620pw, I'll put it Craigslist and I'll get the cs-800. I've had much better luck with my Echo's. Had a bad experience with Stihl and can't get over the fact that Husq is a fancy Poulon. I bought the ea 7900 over the cs-800 because I thought the cs-800 would be harder to pull start because it doesn't have the same start system as the cs-620pw. I'm beginning to regret my decision and feel like I wasted money on this saw.

Fingers crossed that I can get this saw fine tuned.

 

[Andyshine77]

You can't put down a saw because it's not tuned properly or the chain isn't set up properly, that's on the user. The 7900 is a phenomenal saw and should most surely outperform your Echo, it sounds like the carb is tuned way too rich. Follow the tuning instructions in my video, or find someone local that knows how to tune a saw. I'm not into milling, but you will get better use out of your chain if you file the top plate to 10° using a progressive depth gauge is a must, and very important.

Husqvarna's are not in any way glorified Poulan, unless you're talking about a couple super low end models, I'm not sure where you got that crazy information.

 

[ocean4surfing]

You can't put down a saw because it's not tuned properly or the chain isn't set up properly, that's on the user. The 7900 is a phenomenal saw and should most surely outperform your Echo, it sounds like the carb is tuned way too rich. Follow the tuning instructions in my video, or find someone local that knows how to tune a saw. I'm not into milling, but you will get better use out of your chain if you file the top plate to 10° using a progressive depth gauge is a must, and very important.

Husqvarna's are not in any way glorified Poulan, unless you're talking about a couple super low end models, I'm not sure where you got that crazy information.

Thanks. I'm not a quitter; I'm going to try tuning it before i give another company my business. However, I'll say that right now I'm not real happy. It just seems crazy for me to have to spent $1000 on a saw that's not ready to use. I'm fine with maintaining it, but me, the customer, needing to tune a product that German engineers and QC should have ready out of the box for the consumer that just paid $1000 for it, is just plain ridiculous. I have never had to tune a Makita circular saw, drill, belt sander before it did the job. Makita is well known to be the best and IMO they really screwed up here unless I have a lemon. I'm an engineer and that's not how we do things. It makes me mad to think that if I can't fix this on my own, I may need to take a brand new saw and pay more money so that it idles properly and revs to 12,000 - 12,500 like it should. I'm not exactly a rookie with chainsaws. I've been cutting for several years and owned several saws. I don't think a person that's an arborist for a living wants to deal with this kind of stuff either. I'm still thinking I just have a lemon that is going to take a bit more TLC to get running the way the engineers that designed it intended . Trying to be optimistic.

I have nothing against Husqvarna, I own one of their weed wackers and it works well, but if you think about how other parent / child companies are it just makes me wonder what's under the hood and for someone like me, it might make me choose a different brand when there are lots of other options and the tool I'm buying is probably the most dangerous tool there is.

 

[KiwiBro]

Place that trash up for sale in the trading post on this site. Some idjit will buy it off you.
;-)

 

[ocean4surfing]

Hooked tachometer up to it and it revs to 12100-12300 range. Idle was indeed set too low so adjusted that, but that won't make it cut any better. It will reduce the annoyance of it cutting off though when letting off the throttle. I wonder if this saw doesn't like the HD filter much. With the cover off it will blow the outer filter cover off and seems like it runs better in the winter setting and with the outer cover filter off. Back to drawing board. So here's where I'm at...sharp chain (throws nice chips when cutting upright, throws dust when on its side), revving to 12200ish, still struggles to pull 32" bar through 22-24" poplar. Have to zig and zag my way through and it takes nearly two tanks of gas for a 10' section. From what I understand about milling a chainsaw should not have to be pushed or zig zagged through the wood. Not sure what else to try.

 

[toadman]

Thanks. I'm not a quitter; I'm going to try tuning it before i give another company my business. However, I'll say that right now I'm not real happy. It just seems crazy for me to have to spent $1000 on a saw that's not ready to use. I'm fine with maintaining it, but me, the customer, needing to tune a product that German engineers and QC should have ready out of the box for the consumer that just paid $1000 for it, is just plain ridiculous. I have never had to tune a Makita circular saw, drill, belt sander before it did the job. Makita is well known to be the best and IMO they really screwed up here unless I have a lemon. I'm an engineer and that's not how we do things. It makes me mad to think that if I can't fix this on my own, I may need to take a brand new saw and pay more money so that it idles properly and revs to 12,000 - 12,500 like it should. I'm not exactly a rookie with chainsaws. I've been cutting for several years and owned several saws. I don't think a person that's an arborist for a living wants to deal with this kind of stuff either. I'm still thinking I just have a lemon that is going to take a bit more TLC to get running the way the engineers that designed it intended . Trying to be optimistic.

I have nothing against Husqvarna, I own one of their weed wackers and it works well, but if you think about how other parent / child companies are it just makes me wonder what's under the hood and for someone like me, it might make me choose a different brand when there are lots of other options and the tool I'm buying is probably the most dangerous tool there is.

Hooked tachometer up to it and it revs to 12100-12300 range. Idle was indeed set too low so adjusted that, but that won't make it cut any better. It will reduce the annoyance of it cutting off though when letting off the throttle. I wonder if this saw doesn't like the HD filter much. With the cover off it will blow the outer filter cover off and seems like it runs better in the winter setting and with the outer cover filter off. Back to drawing board. So here's where I'm at...sharp chain (throws nice chips when cutting upright, throws dust when on its side), revving to 12200ish, still struggles to pull 32" bar through 22-24" poplar. Have to zig and zag my way through and it takes nearly two tanks of gas for a 10' section. From what I understand about milling a chainsaw should not have to be pushed or zig zagged through the wood. Not sure what else to try.

I believe my 7900 runs at the same, or very close to the same top speed, although it is advertised as 12,800.
I used to fight with getting my chains to bite in end grain milling, and as a heavy guy I just put my back into it and leaned on the sled a lot... I had a guy teach me to sharpen properly & that made a huge difference.
The other difference, and this didn't get put to use until I realized I couldn't push it through very well with broken ribs & a concussion from a bike crash, was a little mechanical crank winch.
Oh my god, that was a lifesaver!!!
Not so much when my chains are perfect, or if I am fresh, but if I mess up a bit on my chain, or want to cut a third slab before sharpening, I can & with far less effort.
as far as tuning a saw goes, I don't even notice I'm doing it sometimes. It is automatic. saw sounds funny? Doesn't run right? Idles funny? Out comes the little screwdriver...it takes very little time, and practically no effort after a while to keep a well known saw in tune.
I do absolutely love the auto tune & M tronics. It does save a little time & I appreciate a machine running 100% all the time, as I go from 600 ft to 4000ft frequently & my grandparents live above the tree line (11,000ft) in CO, and I cut there when there's a load delivered each fall.
Without auto tune, there's absolutely no way a carburetor will compensate for that difference in altitude, and they have zero way of knowing which saw will be at sea level & which saw gets sent to the mountains.
Heck, if I took my saw to the closest saw shop to my grandpa's for a tune, it would be 4700ft of elevation off in the tune & might not even run at his house.
I used to carry 2 carburetors for my chevy when I went out to his house from Kansas & I would swap in denver, or be spitting fuel out my exhaust pipe and having the motor shut off constantly due to flooding it with to high fuel to air.

 

[Andyshine77]

Learning how to tune a chainsaw is a must for anyone who uses a saw regularly IMHO. So far the Mtronic and AT saws have reported to not take kindly to milling applications, maybe the new generations of AT and Mtronic will preform better.

Sounds like your chain is still not set up correctly. Milling only produces dust no matter how good the chain in, and yes you have to push, that's part of the game.

What angles are you using on the chain, and how are you setting the depth gauges?

 

[ocean4surfing]

Good idea on the crank Toadman. I weigh 145lbs, so maybe between my weight and pushing I'm not applying enough force. A crank will definitely help apply more force. It's confusing because all the milling guides say not to push the saw through, but I guess they mean don't push on it with too much force. Wow, can't imagine doing anything with broken ribs. Broke mine once and it hurt to talk.

Andy, for sharpening, I use the blue Husq rolling sharpening widget with round file and flat file for rakkers. When I set the widget on the chain it sets the angle for the file. I've tried setting the rakkers up for soft and hard wood. Doesn't seem to have an effect. Chain seems as sharp as a new chain, but I'm a rookie at sharpening. Guides say tacky like a cat claw and that's how it feels. I just ordered a Timberline sharpener system and maybe that will do a better job than I'm doing with this Husq widget for sharpening I've heard a lot of people mill with the 372xp and this ea 7900 saw has both more HP and a bigger engine. Maybe there's something like you said about those other saws that make them more suited to milling or most folks aren't milling logs as large as the ones I'm doing . This saw bucks like a champ and I think with 12" width logs, it'd probably tear through easily.