Spark Plug Wisperers?

[MAWoodsman]

Hoping to get a little feedback on anyone with a keen eye for reading spark plugs.
The first pic is out of my 4910 (ported, muff mod)
The second pic (with the orange cord in the background) is out of my 2511p. (just muffler mod)

The both 4 stroke out of the cut, but clean up in the cut. Both cut great.

 

[ballisticdoughnut]

Looking good to me. If the saw is running right and your getting a good no load four stroke I’d say continue on. Some may say they’re a little too light but I see lighter color on autotune and mtronic saws and they’re not blowing up left and right.

 

[Bob Hedgecutter]

Just do what I do- read the saw tune by ear and performance- no oddball traits like bogging from idle and crap like that- let the spark plug do what it will do. Most of mine could be purple for all I know- they dont come out unless they stop sparking.

 

[buzz sawyer]

Both look good to me.

 

[bwalker]

Looking good to me. If the saw is running right and your getting a good no load four stroke I’d say continue on. Some may say they’re a little too light but I see lighter color on autotune and mtronic saws and they’re not blowing up left and right.

Sparkplug color is affected by so many variables that it's pretty much useless. Any info you get from observing your well used plug is so coarse and general that it's very possible to have a decent color plug and be dangerously lean.
A tach is much better way of tuning a saw.

 

[82F100SWB]

A tach in the hands of someone who only knows to tune to the RPM in the box is more dangerous to the health of a saw than anything IMHO.

 

[bwalker]

A tach in the hands of someone who only knows to tune to the RPM in the box is more dangerous to the health of a saw than anything IMHO.

Not really. If one sets to the factory no load spec you will be close. This is assuming no rev limiter or mods.
It's a given most guys can't set a carb to save their lives... especially by ear.

 

[Bob Hedgecutter]

Not really. If one sets to the factory no load spec you will be close. This is assuming no rev limiter or mods.
It's a given most guys can't set a carb to save their lives... especially by ear.

Any tuning adjustments come with risk if being done by untrained ears or eyes on a tach screen- there are too many variables around fuel condition, mix, air and possible faults in saw health/condition that can interfere with either.
How many saws have been killed by owners trying in vain to "tune" out an air leak?

 

[bwalker]

Any tuning adjustments come with risk if being done by untrained ears or eyes on a tach screen- there are too many variables around fuel condition, mix, air and possible faults in saw health/condition that can interfere with either.
How many saws have been killed by owners trying in vain to "tune" out an air leak?

I agree on trying to tune around a air leak.
An engineer friend of mine tried to do this exact thing on his well worn 044. Still couldn't get it to run right(at least he recognized that). When I looked at it I noticed the HS was turned way out. Raised a red flag and quickly I found a tear in the intake boot. Got that replaced and it runs like a top.
However, I will say using a tach to tune to the factory no load setting is pretty fool proof if not exactly bang on. Much better than something subjective like hearing the engine four stroke, which is a crude method anyways and often results in a overly rich tune.

 

[bwalker]

Since we are talking about tuning by spark plug. What would the whisperers say the tune is like on these?

 

[ZeroJunk]

I have to agree with Walker. If the saw shows a max no load RPM of 13,500 for instance I tune them to 13,000 and send it out the door.

I suspect of those who think they can tune by ear maybe 10% can. If I tuned by ear I would have it at 12,000.

 

[bwalker]

I have to agree with Walker. If the saw shows a max no load RPM of 13,500 for instance I tune them to 13,000 and send it out the door.

I suspect of those who think they can tune by ear maybe 10% can. If I tuned by ear I would have it at 12,000.

IME expiereance most people who tune by ear end up way rich. Myself included.
For my own saws in the days before auto tune and the like I woukd spend some time making cuts until I found the max no load the saw cut best at. I would then mark the top cover with a sharpie and have a exact point to tune to from there forward. Never had any issues doing this and it sure saved time when I worked in the woods.

 

[Bob Hedgecutter]

How do you get on with limited coil saws?

 

[bwalker]

How do you get on with limited coil saws?

Start excessively rich and tune until you hit the no load RPM.

 

[ZeroJunk]

IME expiereance most people who tune by ear end up way rich. Myself included.
For my own saws in the days before auto tune and the like I woukd spend some time making cuts until I found the max no load the saw cut best at. I would then mark the top cover in sharp and have a exact point to tune to from there forward. Never had any issues doing this and it sure saved time when I worked in the woods.

I spent quite a bit of time with a 394XP in particular to try and find the difference between max RPM settings and timed cuts in an about 30 inch piece of Red Oak. When you get above say 12,000 and try and measure any gain by going leaner I could not time it in any meaningful way. Measured against a damaged saw is a little silly IMO. I suppose you could damage a saw running rich , but I have yet to see it.

 

[blackoak]

I have repaired many toasted saws over the years because of Rednecks with little screwdrivers working on them

 

[MAWoodsman]

However, I will say using a tach to tune to the factory no load setting is pretty fool proof if not exactly bang on. Much better than something subjective like hearing the engine four stroke, which is a crude method anyways and often results in a overly rich tune.

Are you tuning ported saws to factory settings? Ive found my ported 4910 did not like factory settings (4 stroking in the cut).

 

[bwalker]

I spent quite a bit of time with a 394XP in particular to try and find the difference between max RPM settings and timed cuts in an about 30 inch piece of Red Oak. When you get above say 12,000 and try and measure any gain by going leaner I could not time it in any meaningful way. Measured against a damaged saw is a little silly IMO. I suppose you could damage a saw running rich , but I have yet to see it.

When you run them daily it becomes pretty apparent where they are happiest. A half day or so falling is cutting is usually sufficient.

 

[bwalker]

Are you tuning ported saws to factory settings? Ive found my ported 4910 did not like factory settings (4 stroking in the cut).

No, as I mentioned in post #7 once you muffler mod or port the factory settings go out the window.

 

[bwalker]

I spent quite a bit of time with a 394XP in particular to try and find the difference between max RPM settings and timed cuts in an about 30 inch piece of Red Oak. When you get above say 12,000 and try and measure any gain by going leaner I could not time it in any meaningful way. Measured against a damaged saw is a little silly IMO. I suppose you could damage a saw running rich , but I have yet to see it.

I can't prove this, but I have a feeling running a 2 stroke excessively rich tends to wear the intake side piston skirt more than normal from fuel washing. It would stand to reason that it would also wear other parts more as well. Again this is just a gut feeling I have based on some observation over time and mostly on piston port motors other than chainsaws.