090AV running 9/16 chain

[Metallichg]

I finished rebuilding my 090AV-new seals, bearings, PC etc. It has a 7 pin rim sprocket running 9/16 chain. Idle is set to 1657-used a photo tachometer, max is 7300 when governor kicks in. I have 2 questions-is running 9/16 chain at that speed a bad idea or not? It cuts 6-18" logs well but bogs down if I push it too hard. Oiler is turned up high, but when I go from idle to full throttle, the chain smokes as it rounds the hard nose. The chain is looser than I normally adjust to (chain slides easily by hand). Do you guys see a problem running this chain on a direct drive saw? I'm thinking of going down to 1/2" but wanted to know if others have run the same chain?

Also, when I adjust the low speed screw so the chain just stops (clutch disengages), I'm getting a non-consistant stalling issue. I did a pressure and vacuum test on the saw (without the carb) and it held for 3-4 min. Being a throttle cable saw, I had to replace the outer cover of the throttle cable, as the old cable cover was trashed. I had to thread a small spring around the inner cable to assist in bringing the saw to touch the butterfly adjustment screw when letting off the throttle. The cable is not as smooth sliding in the sheath as I think it needs to be for the carb spring to be strong enough to pull the butterfly back to the idle screw each time. To help get idle RPM's down enough to stop the chain, I had to adjust the low speed screw. Now I have this erratic stalling issue. has anyone else had this problem on an early AV saw? Suggestions? thank you

 

[fwgsaw]

View attachment 584359 View attachment 584358 I finished rebuilding my 090AV-new seals, bearings, PC etc. It has a 7 pin rim sprocket running 9/16 chain. Idle is set to 1657-used a photo tachometer, max is 7300 when governor kicks in. I have 2 questions-is running 9/16 chain at that speed a bad idea or not? It cuts 6-18" logs well but bogs down if I push it too hard. Oiler is turned up high, but when I go from idle to full throttle, the chain smokes as it rounds the hard nose. The chain is looser than I normally adjust to (chain slides easily by hand). Do you guys see a problem running this chain on a direct drive saw? I'm thinking of going down to 1/2" but wanted to know if others have run the same chain?

Also, when I adjust the low speed screw so the chain just stops (clutch disengages), I'm getting a non-consistant stalling issue. I did a pressure and vacuum test on the saw (without the carb) and it held for 3-4 min. Being a throttle cable saw, I had to replace the outer cover of the throttle cable, as the old cable cover was trashed. I had to thread a small spring around the inner cable to assist in bringing the saw to touch the butterfly adjustment screw when letting off the throttle. The cable is not as smooth sliding in the sheath as I think it needs to be for the carb spring to be strong enough to pull the butterfly back to the idle screw each time. To help get idle RPM's down enough to stop the chain, I had to adjust the low speed screw. Now I have this erratic stalling issue. has anyone else had this problem on an early AV saw? Suggestions? thank you

Personally I would run 1/2 chain or .404. 9/16 in my opinion is better suited on a gear drive.

 

[Metallichg]

Do you think it is unsafe, or just going too fast with not enough power? I think I will go with 1/2", but wanted to get some opinions first.

 

[fwgsaw]

Do you think it is unsafe, or just going too fast with not enough power? I think I will go with 1/2", but wanted to get some opinions first.

Probably nothing really safe with that saw. Even more dangerous using a big gear drive. My opinion is 9/16 is a tad big for a direct drive 090 but it can be used on a short bar or for cookies.

 

[Metallichg]

Probably nothing really safe with that saw. Even more dangerous using a big gear drive. My opinion is 9/16 is a tad big for a direct drive 090 but it can be used on a short bar or for cookies.

The

 

[Metallichg]

Thank you, I am planning to try a 7 pin sprocket on a 090g with 9/16 chain. I have a broken 404 drive sprocket that is at the heat treater now, to anneal so I can machine it to accept a McCollugh 9/16 sprocket. The 404 stihl 090g drive sprocket is 64 hardness on the Rockwell c scale (mega hard). I think it will be fun to try.

 

[Robin Wood]

are the drive links rubbing the bar groove ?

 

[Metallichg]

I don't think so, everything looks normal-saw drive teeth are not bottoming out in bar groove. Both are 063 width. It is a hard nose bar.

 

[Robin Wood]

try taking out bar and chain and while the chain fitted on the bar turn the chain around to see if it pinches in any specific spot. sometimes 1 or 2 drive link can be wider and bar groove narrower in some spots when brand new

 

[Metallichg]

I see what you are saying, I will check that.

 

[Modifiedmark]

Personally, I think you should forget the 9/16" chain on both Stihl saws, the direct drive and the gear drive. If I was looking hard to find 9/16" chain I wouldn't want to run that pin drive sprocket either as it can beat the drive links up pretty hard.

There are other saws out there that need that 9/16" chain, and were made for it. Some Remington's and Mall's come to mind right off the bat.

It's too easy to put .404 on the 090 and will probably cut best with that as well. As to the 090G, 1/2" on a short bar might be good, but at a GTG I watched a very nice good running 090G struggle with a long bar and 1/2" chain, so I wouldnt bother with 9/16" on it either.

 

[ironman_gq]

I've got an old Homelite that needs a 9/16 chain if I ever spend the time to get it running

 

[Robin Wood]

not sure if anyone noticed but your felling spikes are upside down ?
will be handy when you cut from bottom when a tree is downed lol

 

[Metallichg]

Oops, I had just put them on before I snapped that shot.

 

[Metallichg]

Personally, I think you should forget the 9/16" chain on both Stihl saws, the direct drive and the gear drive. If I was looking hard to find 9/16" chain I wouldn't want to run that pin drive sprocket either as it can beat the drive links up pretty hard.

There are other saws out there that need that 9/16" chain, and were made for it. Some Remington's and Mall's come to mind right off the bat.

It's too easy to put .404 on the 090 and will probably cut best with that as well. As to the 090G, 1/2" on a short bar might be good, but at a GTG I watched a very nice good running 090G struggle with a long bar and 1/2" chain, so I wouldnt bother with 9/16" on it either.

Thank you for sharing your experience. I think the 9/16 is going to end up back in the box with the roll of chain, but at least for the record, we know what running 9/16 on a non gear saw with a 7 pin rim sprocket does. -makes huge chips, smokes the bar and runs the 090 out of power (boggs down easily). maybe a 5 pin would be better, but that is impossible to make.

 

[Modifiedmark]

Thank you for sharing your experience. I think the 9/16 is going to end up back in the box with the roll of chain, but at least for the record, we know what running 9/16 on a non gear saw with a 7 pin rim sprocket does. -makes huge chips, smokes the bar and runs the 090 out of power (boggs down easily). maybe a 5 pin would be better, but that is impossible to make.

There is not, never were many direct drives that were worth a damn with 1/2" chain, let alone 9/16. I have a 1/2" sprocket to fit my Poulan 91 and I thought about trying it, but I never bothered as I pretty much know what would happen.

Poulan, Remington, Homelite and some others used a lot of 7/16" pitch chain at one time and to be honest, something like that could be used on some large direct drive saws if they made a decent version of it but that ain't going to happen. If done right and on the right old saw, old 7/16" chipper will out cut modern .404.

 

[cbfarmall]

There is not, never were many direct drives that were worth a damn with 1/2" chain, let alone 9/16. I have a 1/2" sprocket to fit my Poulan 91 and I thought about trying it, but I never bothered as I pretty much know what would happen.

Poulan, Remington, Homelite and some others used a lot of 7/16" pitch chain at one time and to be honest, something like that could be used on some large direct drive saws if they made a decent version of it but that ain't going to happen. If done right and on the right old saw, old 7/16" chipper will out cut modern .404.

Agreed. 1/2" chain made my 995D Homelite look very bad. That was an original spec'd pitch for the time and I suspect that stalling that big chain untold times is what trashed the clutch shoes. .404 is a perfect size for big old direct drives and my 995 loves it. 7/16 might be OK except it is hard to find.

Chris B.

 

[Modifiedmark]

Agreed. 1/2" chain made my 995D Homelite look very bad. That was an original spec'd pitch for the time and I suspect that stalling that big chain untold times is what trashed the clutch shoes. .404 is a perfect size for big old direct drives and my 995 loves it. 7/16 might be OK except it is hard to find.

Chris B.

If any direct drive was up to slinging a 1/2" chain, I would say your 1690 would have the best shot at it.
True 7/16" is hard to find, my wish is that someone would make a modern 7/16" pitch chain now. I guess I might as well wish for 1/2" while I'm at it.

You were with me at the time watching that 090G with that long bar, remember that?

 

[fwgsaw]

7/16 chain is definitely getting harder to find course not that many saws ran it to begin with.

 

[Modifiedmark]

View attachment 584978 7/16 chain is definitely getting harder to find course not that many saws ran it to begin with.

I disagree with that statement, it was quite popular with many brands and models in the 60's.