I have an 056 Magnum II, and I'm trying to check the carb settings on it, 'cause it seemed kind of slow and doggy in the cut. The info my dealer gave me of his computer gives a high idle of 12000 rpm. Is this correct? I can only get 11000 rpm with the H screw bottomed right out. Any of you Stihl techs run into this before? It doesn't seem to be leaning out, even with the H screw right in it runs fine. I don't want to use it like this until I can figure out what's going on.
Setting 056 carb
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dustytools
Addicted to ArboristSite
Check this out. There is a section on carburetor tuning that might help you. www.forestapps.com/tips/tips.htm
jet
Some of the 056 carbs have a fixed jet inside the the brass hi speed nozzle. Replace the nozzle with a non-fixed jet type, and the carb will be fully adjustable.
Some of the 056 carbs have a fixed jet inside the the brass hi speed nozzle. Replace the nozzle with a non-fixed jet type, and the carb will be fully adjustable.
formersawrep
ArboristSite Operative
Every time i read about someone "setting" their saw with a tachometer, I cringe. What you are supposed to do is check your saw with a tachometer to be sure max recommended rpms are not exceeded.
Tim Ard is a good guy and very knowledgeable. The quote from his site is spot on .....
The high speed screw is then turned clockwise to reduce fuel (clockwise reduces fuel). As the fuel mixture is leaned out, the saw will run faster until it sounds as if it is screaming. At this point, turn the high speed screw to the left to allow more fuel until a "flutter" is heard. This is the proper RPM for your saw.
This can be confirmed with a tachometer, but a tachometer alone cannot ensure that you have the right fuel mixture. It is possible that air leaks may prevent you from obtaining the proper fuel and air mixture and you may need to reduce the RPM to hear the "flutter". Therefore, the "flutter" is more important than the tachometer reading. Chain saw operators must understand that the fuel mixture accomplishes two additional functions--cooling of the motor and lubricating the engine. If the saw runs too lean, neither of these functions are accomplished effectively and the saw will be ruined.
Tim Ard is a good guy and very knowledgeable. The quote from his site is spot on .....
The high speed screw is then turned clockwise to reduce fuel (clockwise reduces fuel). As the fuel mixture is leaned out, the saw will run faster until it sounds as if it is screaming. At this point, turn the high speed screw to the left to allow more fuel until a "flutter" is heard. This is the proper RPM for your saw.
This can be confirmed with a tachometer, but a tachometer alone cannot ensure that you have the right fuel mixture. It is possible that air leaks may prevent you from obtaining the proper fuel and air mixture and you may need to reduce the RPM to hear the "flutter". Therefore, the "flutter" is more important than the tachometer reading. Chain saw operators must understand that the fuel mixture accomplishes two additional functions--cooling of the motor and lubricating the engine. If the saw runs too lean, neither of these functions are accomplished effectively and the saw will be ruined.
all ears
A few years ago, Stihl pushed adjust by tach. Then they went back to the by ear method.
Go with by ear, because no two saws will peak at the exact same RPM. You just want it in then powerband when it is loaded in the cut.
A few years ago, Stihl pushed adjust by tach. Then they went back to the by ear method.
Go with by ear, because no two saws will peak at the exact same RPM. You just want it in then powerband when it is loaded in the cut.
Lakeside53
Stihl Wrenching
Ears don't work well on the newer saws at all... Try to set a 200t, 361 or 441 by ear only...
I use both. Set by ear to make sure it's running right, then tach it.. One of the best guides is the standard carb setttings. Assuming it's not modified, the saw should be "close" or slightly too rich at standard settings, If it's not, you are compensating for another problem.
I use both. Set by ear to make sure it's running right, then tach it.. One of the best guides is the standard carb setttings. Assuming it's not modified, the saw should be "close" or slightly too rich at standard settings, If it's not, you are compensating for another problem.
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Lakeside53
Stihl Wrenching
What is you compression? Muffler screen?
Your carb may be faulty also... Metering lever set too high, and/or your inlet needle is leaking. Pressure test the carb, and just rebuilt anyhow it if the diaphragms look suspect.
double check
Yep, you should always check the obvious stuff first.
I'm just remembering what I had to do to every one of those 056s that had that setup. Think I still have a couple of those nozzles in stock.
Make sure you back out the high speed needle before you drive the nozzle out.
Yep, you should always check the obvious stuff first.
I'm just remembering what I had to do to every one of those 056s that had that setup. Think I still have a couple of those nozzles in stock.
Make sure you back out the high speed needle before you drive the nozzle out.
Sorry I've been so long replying to all your helpful advice, But I went on information overload!:hmm3grin2orange: Really, though, I just haven't had time to check my computer. The reason I posted this thread was not because I wanted extract the max rpm out of my saw so much as to get it to perform the way it should. If I compare it to my 044 with the Big Bore kit, I know it won't have the speed, but I would have thought I'd notice a definate increase in torque. So, I checked it with my tach, and it read at 10,000 or so. I tried to turn the Hi screw in, and it already was turned in pretty well as far as it would go, I just got a whisker of a turn out of it. I've never seen a saw running with the Hi crew that far in before. Lakeside, on a previous thread you mentioned something about the Mag IIs having holes drilled in the airbox somwhere. This one has no holes in the airbox. How much difference do you think that would make?
As far as compression, muffler carb diaphragms, etc., I'll get there yet, I just gotta find time!:bang: Got the inlaws out from Back East, so been busy with them. Stihltech how do I know if a nozzle is fixed or adjustable? Thanks for all the help you guys, I'm a HD mechanic, if chainsaws were diesels I could be the one with the answers!
Lakeside53
Stihl Wrenching
Some, but the easy way to test it is run it without the cover. Rebuild the carb, but test it for leaks first by applying 10lb of pressure on the fuel inlet and see if the inlet needle leaks.
nozzle
The brass nozzle is visible when the metering diaphragm is removed. There will be a small hole visible in the top of it.
The brass nozzle is visible when the metering diaphragm is removed. There will be a small hole visible in the top of it.
Well, the compression is 150 lbs, and the the muffler screen, well, it's not there anymore, so that eliminates those areas, I think. Next I'll check the carb, but I'll have to wait til I have a carb kit.
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