Chain and bar setup for muffler modded 7900?

[cbr929rr]

Saw will be wearing a 28" bar for felling large trees only part time. When the wood is down it will wear a 20" bar and chain 85% of the time for bucking.

 

[KindlingKing]

Saw will be wearing a 28" bar for felling large trees only part time. When the wood is down it will wear a 20" bar and chain 85% of the time for bucking.

I'm guessing any of the above, given the comments I've heard on this site. Never ran one, so my opinion doesn't have anything behind it. You don't say if you are cutting hardwood or softwood, or a mix. I'd think that if you were in hard wood, you might want to have a full skip chain, especially when it comes time to sharpen. Hopefully you'll get some good replies from folks with some actual trigger time on one of these saws. I understand it'll outpull a 460, so I think you are covered. I wouldn't hesitate to put full comp chain on my 660 with a 28" bar in hardwood except for the fact that it takes so long to sharpen all those teeth.

 

[redprospector]

My 7900 isn't muffler modded......yet. I don't get much hardwood to cut, but I do cut some Douglas Fir. It generally wears a 28" bar with full comp 7 pin sprocket, but has worn up to a 36" bar (skip). In hardwood you'd probably want a skip chain, the 7900's a good saw, but it does have it's limits.

Andy

 

[blsnelling]

I run an 8-pin with full comp and a 28" on my ported 460. I'm thinking your 7900 could too. Give it a try.

 

[huskydave]

There is only one way to find out. You should try out a few different setups and go with what works best for you. The advise given is a good guide but it all boils down to what works well for your saw cutting your wood and using your technique. The type of chain used comes into play and how it is sharpened as well. I am always experimenting and it has payed off with a faster cutting saw and a more enjoyable day. I voted 28" skip chain with 7t sprocket and I would run rsc chain to start with and experiment from there.

 

[computeruser]

7t, definitely. As for skip/comp, the choice is yours; try both and see what you like.

I run both skip and full-comp at 28", but usually grab the skip loops with the 7900. It pulls full-comp well enough to run all day, but 28" full-comp is 066/8t territory, a much faster setup than the 7900 under any circumstance.

 

[NPKenny]

If you were not opposed to changing the rim sprocket when you change the bar and chain, you could opt for all of those options.

I have not run the 28" bar on mine as of yet, but I have a few hours with both the 7t and 8t on the 20" bar. If this is how you run the saw most of the time, you will prefer the 8t rim.

My 7900 has a muffler mod and a slight cleaning of the ports and transfers. I'm also at 6000' if that helps you with your decision.

 

[rahtreelimbs]

A 7 tooth makes for a more forgiving saw over an 8 tooth. What you are gaining ( 8 over a 7) in cutting wood meant for a 28" bar will be moot!!!

 

[JT78]

Im not sure how many teeth the stock sprocket has but running the stock sprocket I have had my 7900 buried in Hickory,Oak and Sycamore wearing a 28 inch bar with full comp and it pulls really good. I tried full skip and saw no difference in cutting times just less teeth to sharpen. I can also add that mine has yet to be muffler modded it is completely stock right now.

 

[SawTroll]

There is only one way to find out. You should try out a few different setups and go with what works best for you. The advise given is a good guide but it all boils down to what works well for your saw cutting your wood and using your technique. The type of chain used comes into play and how it is sharpened as well. .....

Right, but those words really are mine....LOL