Sprocket change out to increase torque with larger CC saws.

[telecasterfool]

The comments pertaining to chain sharpening and species are correct. However, unless the process of changing the sprocket is daunting, why not just purchase an 8 tooth rim drive for your saw and try it? It won't hurt anything. I was curious, and I have other saws, so I set up an Echo CS-600P with a 24" bar, .325 full chain and 9 tooth sprocket.

 

[PapaWhitebeard]

force= torque in the case of an engine any time you can get something in the drive line with the gearing the felt torque is changed, better or for worse. Don't bother trying to explain it to him, he will argue till you're blue in the face and throw every equation and anything else he can find on the internet to prove you're wrong, when in fact you're absolutely right.

(Yeah… I suppose this is the reason I stay off the interweb… it seems like everybody wants to fight all the time (?!!)

But yeah… even through I’m a 4th generation white trash farmer who finally made it off the farm, I done learned a few things over the years

Like if someone wants to learn or have a different point of view I don’t mind. And im well aware of the Dunning Kruger effect (where people in the bottom quartile think they’re geniuses ) but man I’ve never seen it so much as I have on the interweb… (shrug)

“Nobody died”

 

[sean donato]

That is an interesting attachment.

Does the Zenoah share same bar mounts with other saws? Also would like to see detail of the clutch belt drive system and if that could be adapted. Is it just a special rim for the clutch drum?

I still save my old bars/chains/rims for "stumpers" and/or trees that might have metal in them.

It's the same belt drive used in cut off saws, other then having a spur for a chain instead of a hub for a cutting wheel.

 

[PapaWhitebeard]

Gear down for torque, gear up for speed.

THAT

 

[PapaWhitebeard]

Take a look at Zenoah RC6200P. A belt is used for power transmission. You can also see the line run between the powerhead and the attachment. They use it to cut roots.

View attachment 1205119
View attachment 1205121

Note the itty bitty flywheel sprocket (ie to generate more torque) and the relatively larger drive wheel for the belt (also to increase torque—radius increase at what is essentially the rear sprocket function opposite as radius increase at front sprocket ie at the flywheel)

That thing is a torque monster!

 

[PapaWhitebeard]

THIS is exactly like how motorcycle gearing works. The guy is using a 7 tooth sprocket and the radius of the drive wheel for the belt functions like a rear sprocket. If you look at the motorcycle “stunter” crowd they’ll put super tiny sprocket on the front (ie flywheel) and *enormous* sprockets on the rear tire so they can increase torque at the rear tire and wheelie at will… but they don’t have very much top speed capacity… but for guys who just wheelie in parking lots they don’t care about high top speed.

Conversely motoGP racers will add teeth to the front sprocket to increase chain speed and reduce the teeth on the rear sprocket for the same reason… so they can get those bikes up to 200 mph…

Same applies to our saws… add teeth to the sprocket… get higher chain speed. By my calculations on a 20 inch bar one tooth increase is ~7% increase in chain speed FWIW

 

[muddy42]

I will mess with exhausts but don't touch the rest. You are unlikely to do better than the manufacturers with their million dollars R&D budgets. If they left a performance enhancement untapped, in time a competitor would use it and then you'd get the youtube speed comparisons, power weight tests etc. If I want a more powerful saw I grab a more powerful saw. Sharp chain will always be the most important thing.

 

[PapaWhitebeard]

I will mess with exhausts but don't touch the rest. You are unlikely to do better than the manufacturers with their million dollars R&D budgets. If they left a performance enhancement untapped, in time a competitor would use it and then you'd get the youtube speed comparisons, power weight tests etc. If I want a more powerful saw I grab a more powerful saw. Sharp chain will always be the most important thing.

Yeah… all that’s true. But they’re doing all that already. Look at the OEM saws they sell in say Australia with no EPA restrictions no California CARB restrictions etc. OEM from Stihl they build them different than the saws they sell in the US.

You’re right that manufacturers these days know what they’re doing they have loaded tons of money into R&D. All true.

But the same is true with vehicles and pretty much anything that burns gas… OEM product is different in regulated jurisdictions vs places where there are less regulations.

Plus changing a sprocket isn’t rocket science. Like changing bar size is no big deal… everyone has different needs.

I mean I sure agree with the notion of “if it ain’t broken don’t fix it” for sure. But if you can make it better and you want to make it better and you’re the kind of fella who likes making it better… yeah I respect that too.

 

[fields_mj]

I will mess with exhausts but don't touch the rest. You are unlikely to do better than the manufacturers with their million dollars R&D budgets. If they left a performance enhancement untapped, in time a competitor would use it and then you'd get the youtube speed comparisons, power weight tests etc. If I want a more powerful saw I grab a more powerful saw. Sharp chain will always be the most important thing.

Not even close to true. If it were true, there wouldn't be an entire industry around porting saws, and nobody would be willing to spend hundreds of dollars to have their saw ported.

As far as motorcycles vs chainsaws, WHO GIVES A FLYING RIP! The guy is asking about options for making his saw cut faster.

As others have said, its a mater of matching your saw to the cutting conditions, and a sharp chain always helps. Knowing what saw you have, how many teeth/pins your sprocket/drive rim has on it, what you're cutting, your bar length, and the type of chain you're using are critical pieces of information that are needed before someone can give good advice. If you are NOT using a rim and sprocket setup, I WOULD strongly recommend switching to it. As others have mentioned, it's cheap and easy to switch rims as needed for different applications.

Personally, most of my cutting is for my own firewood also. I do most of my bucking with an 036, and I mostly cut shagbark hickory that's around 20" at the base, and I don't cut anything under about 6" in diameter. On my 036, I run an 18" bar with .325 full chisel chain. That happens to be what was on both of my 036 saws when I bought them, but its also what I run on my 026, 024, and its what my dad runs on his 028, so there's a benefit for me to use "common parts" between most of my saws. I found that while bucking with my 036, I could lean on the saw pretty hard without bogging the saw down. I replaced my drive bearing and sprocket so that I could run the larger drive rims which has a 9 pin (9 tooth) drive rim for .325 chain. That gives me a higher chain speed that utilizes some of the extra power that's available from the saw. I also drop the depth gauges slightly more than the 0.025" stock setting. It makes for a relatively light, fast cutting saw for bucking most firewood. In stuff that's 10"-12", it holds its own against a 90cc saw running a 28" bar. That doesn't mean that the bigger saw isn't faster, it just means that there's not enough difference for ME to worry about. The draw back to this set up is that its pretty grabby, so dealing with small limbs can be a pain in the rear. Even if I'm taking off 6" limbs, the chain can grab and bog the saw down. On my 026, I leave the chain set up stock and use it for limbing for this reason. It's also probably worth mentioning that I trailer all of my firewood back to the house in the form of logs that are 15'-16' long, so when I'm bucking firewood, there are no limbs to deal with. My limbing work is done in the woods.

I also have an 064 that I'm in the process of rebuilding. My plan will be to have a 25" full comp full chisel bar on that saw for the purpose of bucking stuff that's 18" or more. I'll run an 8 pin rim and .404 chain on it with the depth gauges set at around 0.040". Should be a fun saw to run.

These are examples of how a slightly larger, or even much larger saw can be setup to handle work that's normally done with saws in the 50cc range.

 

[PapaWhitebeard]

As for porting… I’m deeply in favor of what I view as correcting manufacturing shortcomings. In the history of motors there was a learning curve among humans—cars made in the 60s had intake and exhaust manifolds that simply failed to overlap properly… folks experimented with making the holes the same size… making them bigger… polishing bits of them… balancing motors etc. And man oh man did it make an enormous difference.

As time passed manufacturers have done a better and better job of matching up ports on motors. Of course they can almost *always* be improved but motors have made enormous improvements in even the last 20 years.

For instance, I have a 462 that of course the first thing I did was inspect the intake and exhaust ports… and frankly there was almost no work to be done… they were already matched up perfectly from the factory… so while I was in there I polished the exhaust port, removed the baffle from the exhaust manifold and put a BB on it. I replaced the intake filter with oiled foam variety.

The point is there was very little work required to correct the factory tolerances. Could I improve it more? Sure and maybe I will… but it already spins up to 13.5k and has more HP and torque than any OEM 70cc saw from 20 or even 10 years ago. Maybe at some point I’ll advance the timing and put in an unlimited coil in it, polish weigh and balance the internal rotating mass but for now it runs very well and very strong and I’m curious to see how I like it over the next year or so first.

But yes yes yes we can *always* make a from-the-factory saw cut better suited to our specific intended purpose.

 

[Mad Professor]

Not even close to true. If it were true, there wouldn't be an entire industry around porting saws, and nobody would be willing to spend hundreds of dollars to have their saw ported.

As far as motorcycles vs chainsaws, WHO GIVES A FLYING RIP! The guy is asking about options for making his saw cut faster.

As others have said, its a mater of matching your saw to the cutting conditions, and a sharp chain always helps. Knowing what saw you have, how many teeth/pins your sprocket/drive rim has on it, what you're cutting, your bar length, and the type of chain you're using are critical pieces of information that are needed before someone can give good advice. If you are NOT using a rim and sprocket setup, I WOULD strongly recommend switching to it. As others have mentioned, it's cheap and easy to switch rims as needed for different applications.

Personally, most of my cutting is for my own firewood also. I do most of my bucking with an 036, and I mostly cut shagbark hickory that's around 20" at the base, and I don't cut anything under about 6" in diameter. On my 036, I run an 18" bar with .325 full chisel chain. That happens to be what was on both of my 036 saws when I bought them, but its also what I run on my 026, 024, and its what my dad runs on his 028, so there's a benefit for me to use "common parts" between most of my saws. I found that while bucking with my 036, I could lean on the saw pretty hard without bogging the saw down. I replaced my drive bearing and sprocket so that I could run the larger drive rims which has a 9 pin (9 tooth) drive rim for .325 chain. That gives me a higher chain speed that utilizes some of the extra power that's available from the saw. I also drop the depth gauges slightly more than the 0.025" stock setting. It makes for a relatively light, fast cutting saw for bucking most firewood. In stuff that's 10"-12", it holds its own against a 90cc saw running a 28" bar. That doesn't mean that the bigger saw isn't faster, it just means that there's not enough difference for ME to worry about. The draw back to this set up is that its pretty grabby, so dealing with small limbs can be a pain in the rear. Even if I'm taking off 6" limbs, the chain can grab and bog the saw down. On my 026, I leave the chain set up stock and use it for limbing for this reason. It's also probably worth mentioning that I trailer all of my firewood back to the house in the form of logs that are 15'-16' long, so when I'm bucking firewood, there are no limbs to deal with. My limbing work is done in the woods.

I also have an 064 that I'm in the process of rebuilding. My plan will be to have a 25" full comp full chisel bar on that saw for the purpose of bucking stuff that's 18" or more. I'll run an 8 pin rim and .404 chain on it with the depth gauges set at around 0.040". Should be a fun saw to run.

These are examples of how a slightly larger, or even much larger saw can be setup to handle work that's normally done with saws in the 50cc range.

Why not use 3/8 on the 064? It'll cut faster and you could use the B/C on the 036 with a rim change.

25" bar, 8 pin, depth gauges at 0.040 and 0.404 chain on a 064 is going bog/stall if you lean on it.

 

[fields_mj]

Why not use 3/8 on the 064? It'll cut faster and you could use the B/C on the 036 with a rim change.

25" bar, 8 pin, depth gauges at 0.040 and 0.404 chain on a 064 is going bog/stall if you lean on it.

Because I don't currently use 3/8 chain on anything else. I could still put the bar and chain on the 036. Not sure that it would pull it very well.

On the 064, I'd start off with the .404 chain stock and see how it ran and then go from there. I've had the 28" bar and 404 chain on it in the past, and it ran fine.

 

[muddy42]

Not even close to true. If it were true, there wouldn't be an entire industry around porting saws, and nobody would be willing to spend hundreds of dollars to have their saw ported.

As far as motorcycles vs chainsaws, WHO GIVES A FLYING RIP! The guy is asking about options for making his saw cut faster.

As others have said, its a mater of matching your saw to the cutting conditions, and a sharp chain always helps. Knowing what saw you have, how many teeth/pins your sprocket/drive rim has on it, what you're cutting, your bar length, and the type of chain you're using are critical pieces of information that are needed before someone can give good advice. If you are NOT using a rim and sprocket setup, I WOULD strongly recommend switching to it. As others have mentioned, it's cheap and easy to switch rims as needed for different applications.

Personally, most of my cutting is for my own firewood also. I do most of my bucking with an 036, and I mostly cut shagbark hickory that's around 20" at the base, and I don't cut anything under about 6" in diameter. On my 036, I run an 18" bar with .325 full chisel chain. That happens to be what was on both of my 036 saws when I bought them, but its also what I run on my 026, 024, and its what my dad runs on his 028, so there's a benefit for me to use "common parts" between most of my saws. I found that while bucking with my 036, I could lean on the saw pretty hard without bogging the saw down. I replaced my drive bearing and sprocket so that I could run the larger drive rims which has a 9 pin (9 tooth) drive rim for .325 chain. That gives me a higher chain speed that utilizes some of the extra power that's available from the saw. I also drop the depth gauges slightly more than the 0.025" stock setting. It makes for a relatively light, fast cutting saw for bucking most firewood. In stuff that's 10"-12", it holds its own against a 90cc saw running a 28" bar. That doesn't mean that the bigger saw isn't faster, it just means that there's not enough difference for ME to worry about. The draw back to this set up is that its pretty grabby, so dealing with small limbs can be a pain in the rear. Even if I'm taking off 6" limbs, the chain can grab and bog the saw down. On my 026, I leave the chain set up stock and use it for limbing for this reason. It's also probably worth mentioning that I trailer all of my firewood back to the house in the form of logs that are 15'-16' long, so when I'm bucking firewood, there are no limbs to deal with. My limbing work is done in the woods.

I also have an 064 that I'm in the process of rebuilding. My plan will be to have a 25" full comp full chisel bar on that saw for the purpose of bucking stuff that's 18" or more. I'll run an 8 pin rim and .404 chain on it with the depth gauges set at around 0.040". Should be a fun saw to run.

These are examples of how a slightly larger, or even much larger saw can be setup to handle work that's normally done with saws in the 50cc range.

Thanks for the detailed response. Yes I have had and used ported or those with a larger cylinder added before, but I meant what I said, porting may work for others, its just not for me. Also dare I say it but one of these won't last long in the hands of someone who cannot sharpen well, forces the saw into wood, doesn't clean air filters, tune etc. Rather than spend hundred of dollars on porting, I have spent hundreds of pounds on fixing up multiple old saws so I have a variety of saws to hand for different tasks (50-120cc). I mostly do storm damage and milling so its not an issue to have a few spare saws in a vehicle near the workplace. Making long cuts in massive knotty hardwood is pretty tough work for any saw.

 

[fields_mj]

Thanks for the detailed response. Yes I have had and used ported or those with a larger cylinder added before, but I meant what I said, porting may work for others, its just not for me. Also dare I say it but one of these won't last long in the hands of someone who cannot sharpen well, forces the saw into wood, doesn't clean air filters, tune etc. Rather than spend hundred of dollars on porting, I have spent hundreds of pounds on fixing up multiple old saws so I have a variety of saws to hand for different tasks (50-120cc). I mostly do storm damage and milling so its not an issue to have a few spare saws in a vehicle near the workplace. Making long cuts in massive knotty hardwood is pretty tough work for any saw.

THAT I completely agree with. Ported saws have their place, but they aren't for me either, and for some of the same reasons.

 

[PapaWhitebeard]

Re motorcycles apologies to everyone for my (admitted) exuberance about them.

I should have left it at “increasing teeth will increase your chain speed but watch out for the torque penalty—if you increase your sprocket size too much that smooth solid torque curve that particular echo is known for may suffer to the point where it bothers you.”

 

[Philbert]

Re motorcycles apologies to everyone for my (admitted) exuberance about them.

Motorcycles, chainsaws, . . . same difference . . .


https://greasengasoline.wordpress.com/2012/06/07/dolmette-the-24-cylinder-motorcycle/

Philbert

 

[PapaWhitebeard]

Motorcycles, chainsaws, . . . same difference . . .

View attachment 1205540
https://greasengasoline.wordpress.com/2012/06/07/dolmette-the-24-cylinder-motorcycle/

Philbert

I love it. It’s utterly ridiculous but I sure love seeing the result of obsession combined with creation… that’s great !

 

[purellbear37]

Thanks everyone.

What I gather from this is; I can experiment with changing the sprocket out and decide if I like it or not. I am not planning on changing out much more on the saw as all my loadouts for bars and chains are all the same.

I may just leave it alone for now.

 

[PapaWhitebeard]

Thanks everyone.

What I gather from this is; I can experiment with changing the sprocket out and decide if I like it or not. I am not planning on changing out much more on the saw as all my loadouts for bars and chains are all the same.

I may just leave it alone for now.

You got it. Just remember if you go up more than one tooth you’re probably going to need to buy longer chains. But yeah that ~7% extra chain speed is material… you’ll feel it for sure.