Different sproket for 7900

[JT78]

I honestly am not sure what sproket it comes with but was wondering if I would see any gain from changing to a different sproket if I am running a 28 inch bar on it. I have both skip and full comp chain that I use depending on the type of wood. What do yall think and what sproket would I need to purchase.

 

[redprospector]

The 7900 (like most saw's) comes stock with a 7 tooth sprocket.
I've found that if you're mostly bucking, it likes the 7 best.
If you're limbing with the same saw you fell with, try an 8 tooth. You'll sacrafice a little stump power, but you'll gain some limbing speed.

Andy

 

[pbtree]

I honestly am not sure what sproket it comes with but was wondering if I would see any gain from changing to a different sproket if I am running a 28 inch bar on it. I have both skip and full comp chain that I use depending on the type of wood. What do yall think and what sproket would I need to purchase.

With the 28 inch, I would be inclined to leave it, although like mentioned above if you are just limbing with it you would probably notice some chain speed increases.

If you are going to be mostly limbing though, I would run a 8 tooth and a 20 inch bar - the thing will smoke!

 

[drmiller100]

hmmmm........

depends on wood.

i'm fundamentally a lazy person. so, i run skip chain so that when i hit a rock it takes less time to sharpen.

and, i run a 28 inch bar so i don't have to bend over as much, and it mounts better on the processor.

also, both my 7900's have been woods ported and fiddled with.

cutting up to 30 inch green white fir, it cuts a little faster with an 8 tooth sprocket then 7 tooth.

smaller stuff the 8 tooth still seems faster.

also, depends on how good you are at sharpening. it seems like the better i get at sharpening, the faster the 7 tooth gets compared to the 8 tooth.

a guy who knows more then me insists the 7 tooth is faster then an 8 tooth usually in this class of saws, but he also cuts harder wood then me.

pretty cheap to try though.

 

[computeruser]

Not sure what you're cutting, but I would think that a 7t would be preferable in most applications. I've tried both setups on mine, and consistently come back to 7t whether for 20" or 28" bars. The 7900 is torquey saw anyway, and with the 7t you can really work the torque - slightly lower rakers, great stump power, and a saw that seldom bogs on anything.

 

[Zodiac45]

I honestly am not sure what sproket it comes with but was wondering if I would see any gain from changing to a different sproket if I am running a 28 inch bar on it. I have both skip and full comp chain that I use depending on the type of wood. What do yall think and what sproket would I need to purchase.

It all depends on what you want to gain? If it's chain speed, then yes, you'll get more out of a 8 tooth. The trade off is in pulling power. Think of it like driving in 4th gear or 5th.

 

[B_Turner]

I have tried 8t and 7t quite a bit in the past, but now run 7t pretty much on all my saws including my 7900s. With a short bar, I grab a smaller saw.

I run full skip on 28 inch and up as it cuts almost as fast and is quicker to sharpen.

Another part of the decision to run 7t for me is that I can get away with one less drive link on my chains so I get more adjustment range on my chains. So with my 7900s I have started running 92 dl because at the usual 93 there is not much adjustment available with certain bars I run, like my 28 inch Cannon. 92 dl solves the problem.

 

[redprospector]

cutting up to 30 inch green white fir, it cuts a little faster with an 8 tooth sprocket then 7 tooth.

smaller stuff the 8 tooth still seems faster.

also, depends on how good you are at sharpening. it seems like the better i get at sharpening, the faster the 7 tooth gets compared to the 8 tooth.

a guy who knows more then me insists the 7 tooth is faster then an 8 tooth usually in this class of saws, but he also cuts harder wood then me.

pretty cheap to try though.

dr,
Like you said; It seem's faster, but I'll bet that if you put a stop watch on it you'd be really surprised.
I can't see any way that in 30" White Fir an 8 would cut faster than a 7. It may seem like it, but it ain't. If you're cutting 8" & 10" pecker poles then the 8 tooth will shine.
But like you said; Pretty cheap to try though.

Andy

 

[redprospector]

I have tried 8t and 7t quite a bit in the past, but now run 7t pretty much on all my saws including my 7900s. With a short bar, I grab a smaller saw.

I run full skip on 28 inch and up as it cuts almost as fast and is quicker to sharpen.

Another part of the decision to run 7t for me is that I can get away with one less drive link on my chains so I get more adjustment range on my chains. So with my 7900s I have started running 92 dl because at the usual 93 there is not much adjustment available with certain bars I run, like my 28 inch Cannon. 92 dl solves the problem.

+1
Dropping the dl count to 92 on the 7900 with a 28" makes life a lot easier.

Andy