Stihl MS291 questions

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VinceGU05 said:
heres a muffler off a 291 i did for my mate. bought it from stihl.. $45 i think it was.. i think a 290 is the same.


heres what i did to my jonersed mixture screws. now i can use the little orange screwdriver on them :D
dremel comes in handy!!
Click to expand...

I think I've seen your muffler mod before. Looks great! Did you progressively add slots or did you just cut in four right away?

I also like the Dremel slots cut into your adjusters. I've done that a few times in my life, and wanted to do it to my old saw which has a "single D" screw. The problem is the screws are recessed in the carb, like the 291 pictures in this thread, so I just bought the special driver kit, which happened to include the spline drive you have.
 
Robin Wood said:
Yes ur right, i dont know much about carb settings yet.
Always thought EPA jets were too narrow to start with for muffler mods or etc.
Click to expand...

Plenty of videos and articles on carb tuning, as you may already know. Not sure how serious you are about this, but having a tach can really help dial in the saw's potential. I would love to hear what you experts say to that, and how it might relate to a muffler mod.
 
Well, I called a local dealer (who I didn't buy the saw from). Read him the part numbers of the puller and screwdriver, he ran the numbers into the computer and then he told me that he couldn't sell me the tools, they were obviously flagged for dealer only. :(

Through trial and error, I found out that the limiter cap threads are left hand twist. Of course!

My next step will be to take it to the dealer I bought the saw from, and see if he will re-tune or give me more adjustment capability. I will follow up to let you know how that goes. He returns from vacation this Monday.
 
Well, after much coaxing (read: begging and pleading), my dealer cannot sell the limiter tools to me. That's a bummer, but I respect it. I did buy a RS chain from him and a Granberg jig from Amazon and I'm more than happy with how the saw cuts. After doing a little research and practice, I can get the chain remarkably sharp. Much more so than with the hand kit. Took down four 16" pine trees this past weekend and the saw just ate them.

Again, thanks everyone for your contributions! I hope this thread will help out others looking for the same information.
 
Check eBay international for the tools... I have a friend who might have been able to get them through the pay Bay.
 
ColdStihl said:
I think I've seen your muffler mod before. Looks great! Did you progressively add slots or did you just cut in four right away?

I also like the Dremel slots cut into your adjusters. I've done that a few times in my life, and wanted to do it to my old saw which has a "single D" screw. The problem is the screws are recessed in the carb, like the 291 pictures in this thread, so I just bought the special driver kit, which happened to include the spline drive you have.
Click to expand...
just marked out the cuts then used the slitting wheel from the dremel. a selection of screwdrivers and pliers, worked the fins up till they looked the part. deburred it and then painted it. all up 1 hr job.
yes can get spline and D shaped drivers off ebay world wide. slotting for me was a cheaper option.

glad you have discovered you can make chains sharp and keep them sharp. RS in pine is great. keep the rakers at 30 to 35 thou and it will rock thru that.

here is the thread i did and feedback from the owner of the saw. hope this helps.
http://www.arboristsite.com/community/threads/muffler-mod-ms291-style.248665/
 
It had been awhile since I read your thread, and I will say again that it looks great. You mentioned that the H didn't need much adjustment. My H came from the dealer maxed out, so I'm worried that I would be too lean after the mod, hence why all the questions with pulling the limiters.

I don't have a lot of pine. The trees I took down were sickly with some sort of bug burrowing into the trunk. My Stihl depth gauge shows me that the RS rakers are at about .030". My questions is, for hardwood should I eventually sharpen my way to .025" or keep the more aggressive depth? I must say that keeping a sharp chain has become an addiction by proxy of how effortless the saw seems to cut.

Speaking of sharpening, does anyone have a clue as to why my RM yellow chain won't allow the Granberg jig to drop into the mouth of the cutter? It seems like the tooth edge and the raker are too close together. I don't have that problem with my RS, or even my Oregon and Carlton chains. I didn't try the RM green chain that came with the saw, but I think the result will be the same.
 
ColdStihl said:
It had been awhile since I read your thread, and I will say again that it looks great. You mentioned that the H didn't need much adjustment. My H came from the dealer maxed out, so I'm worried that I would be too lean after the mod, hence why all the questions with pulling the limiters.

I don't have a lot of pine. The trees I took down were sickly with some sort of bug burrowing into the trunk. My Stihl depth gauge shows me that the RS rakers are at about .030". My questions is, for hardwood should I eventually sharpen my way to .025" or keep the more aggressive depth? I must say that keeping a sharp chain has become an addiction by proxy of how effortless the saw seems to cut.

Speaking of sharpening, does anyone have a clue as to why my RM yellow chain won't allow the Granberg jig to drop into the mouth of the cutter? It seems like the tooth edge and the raker are too close together. I don't have that problem with my RS, or even my Oregon and Carlton chains. I didn't try the RM green chain that came with the saw, but I think the result will be the same.
Click to expand...

Personally i find that you need to go easy on the rakers when dealing with hardwoods and i sharpen 30~35 degree top plate angle for hardwoods.
Otherwise saw might get jammed in the cut and it will vibrate alot(bad for PTO bearings and most parts i guess)
BTW what kind of hardwoods you dealing with ?
 
Robin Wood said:
Personally i find that you need to go easy on the rakers when dealing with hardwoods and i sharpen 30~35 degree top plate angle for hardwoods.
Otherwise saw might get jammed in the cut and it will vibrate alot(bad for PTO bearings and most parts i guess)
BTW what kind of hardwoods you dealing with ?
Click to expand...

Duly noted. I do sharpen at the recommended 30* top plate angle on the Stihl chains.

Mostly Poplar and Maple, a dash of Oak and Birch. Most of what I have been cutting recently is 30 year old Poplar that either blew over or was pretty much dead where it stood. Out-of-the-box chain angles cut really well, but I will always appreciate a good tip to make things faster (and still relatively safe).
 
Why the file doesn't fit?
Because Stihl recomends 4.5mm files and Oregon 4.8mm is what I always thought. But after the first filling I don't have a problem anymore and I use the 4.8mm files because that is what I have.

7
 
7sleeper said:
Why the file doesn't fit?
Because Stihl recomends 4.5mm files and Oregon 4.8mm is what I always thought. But after the first filling I don't have a problem anymore and I use the 4.8mm files because that is what I have.

7
Click to expand...

Hey 7 :cool:

I'm using Stihl files and with the Stihl file guide I can get it in there just fine. I just have to enter at about a 50-degree top plate angle, then position to 30 degrees. My trouble is with the Granberg File n Joint jig. By design, the angles are "locked in", so I can't seem to get the file to drop in without colliding with the top plate and raker simultaneously. If I had to loosen the jig, drop the file in and then re-tighten, that would be a major pain. Just wondering if others had seen this because my other chains have no issue, just the RM series. I'm a mechanical guy and my best assumption would be that the chain would need to be sharpened a few times by hand in order to finally fit the file in using the jig. Aside from the pot metal construction, I have nothing bad to say about that thing. It really makes keeping the chain sharp, fast and easy. I think I am going to mic the cutters on the RS and RM to see if there is a difference. My hunch is that the RM cutter/top plate is slightly longer on a brand new chain than RS. Thoughts?
 
I pulled my H limiter cap. Slightly different from some of the pics I've seen. I have some great pics and observations.

Should I start a new thread for Phase Two?
 

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