safe rpm's

[grantwolland]

Wondering, if the maximum engine speed of my stihl 010 Av is 10,000 rpm's (per the manual) is 9500 a safe no load speed to set the high speed at or does someone have any suggestions as a guideline for a safe range of rpm's in perspective to the maximum rpm of a saw?

 

[BostonBull]

The MAX rpm rating is with the bar and chain ON and out of the wood, with no load. I would say tune it to a little rich maybe 9,600-9,800. If you know how to tune by ear that is the best way to do it, but a TACH is alwyas a good idea to get it close then fine tune by ear.

 

[blis]

usually those rpms listed on manual are +-500rpm, so if it says 10 000 then 9 500 - 10 500 would be ok...

 

[Lakeside53]

Don't push the limiits on an 010... It won't cut any better... and if the reed can even keep up, might come apart.

 

[grantwolland]

Thanks for the input guys. I'll leave it at 9500 since I'd rather clean out carbon than replace pistons. It is an old saw(late seventies) still running points so I'll let grandpa jog slowly. I'm excited to see how it'll cut with a fresh carb rebuild!

 

[Lakeside53]

Run it on 50:1 synthetic mix and you won't have a carbon problem either.

 

[Elmore]

The MAX rpm rating is with the bar and chain ON and out of the wood, with no load. I would say tune it to a little rich maybe 9,600-9,800. If you know how to tune by ear that is the best way to do it, but a TACH is alwyas a good idea to get it close then fine tune by ear.

Correct me if I'm wrong...the rated rpm for saws with reed valves is the working rpm or with the chain in the wood.
With piston ported saws it is with the chain on and not in the wood.....never mind. The 010AV apparently is piston ported so Boston Bulls comment is correct. No reed valve.
On my old German saw I like to run a 32:1 mix of fully-synthetic Mobil 1 Racing 2T with premium fuel, the carburetor adjusted to the mix.

 

[grantwolland]

fuel/oil mixes

Well, this 010 AV has a reed valve under the carb. what is piston porting as you mentioned? is it safe to run a 50:1 synthetic mix (i.e. Stihl brand) in older saws that called for something else? what's your experience? I've already had sticker shock on buying a new cylinder, prefering to hone the existing one. so in my opinion richer is better to protect my older saws(most of what I own) I use a 40:1 synthetic in most of them. what's your experience with premium fuel (93 octane) does the additives in the premium fuel (cleaner etc.) screw with the mix?

 

[blis]

Well, this 010 AV has a reed valve under the carb. what is piston porting as you mentioned? is it safe to run a 50:1 synthetic mix (i.e. Stihl brand) in older saws that called for something else? what's your experience? I've already had sticker shock on buying a new cylinder, prefering to hone the existing one. so in my opinion richer is better to protect my older saws(most of what I own) I use a 40:1 synthetic in most of them. what's your experience with premium fuel (93 octane) does the additives in the premium fuel (cleaner etc.) screw with the mix?

yes, it is safe to run any saw on 50:1 with modern oils, those thicker mixes are remnant from ages when it was common to mix MOTOR OIL with gas...

 

[Lakeside53]

Correct me if I'm wrong...the rated rpm for saws with reed valves is the working rpm or with the chain in the wood.
With piston ported saws it is with the chain on and not in the wood.....never mind. The 010AV apparently is piston ported so Boston Bulls comment is correct. No reed valve.
On my old German saw I like to run a 32:1 mix of fully-synthetic Mobil 1 Racing 2T with premium fuel, the carburetor adjusted to the mix.

Couple of wrongs... it is a reed valve engine, and, it is still the max rpm out of the wood - we are talking WOT.

 

[Lakeside53]

Premium gas is fine, and in my area Chevron still does not have 10% alcohol in premium. The alcohol in the other grades will make the saw slightly leaner. You'll have to check it out in your area.

 

[Elmore]

Couple of wrongs... it is a reed valve engine, and, it is still the max rpm out of the wood - we are talking WOT.

Probably so. I was referencing the Chainsaw Collectors Corner and the notes therein. Also of some advice that I was given a while back in regard to setting the rpm of a little Poulan 2000 with a reed valve engine as opposed to my piston ported Makita 520i. I also was adjusting another 36cc grey colored Poulan that I believe is a either a Poulan 2250 or a Poulan Pro 210. In the collectors corner there was no reference to a Poulan 2250 operating RPM but it states that the 2250 is piston ported so I searched for a listing under Poulan Pro for a 36cc saw made around the time that this Craftsman was bought. I found the Poulan Pro 210 and the operating RPM is stated but not the intake method. Both the 2250 and the 210 look like my saw. Both of those are 36cc as is mine and I imagine that all are piston ported.

Dolmar Model: 111
INTAKE METHOD: Piston ported
OPERATING RPM: 12,500 maximum free speed with bar & chain

Poulan Model: 2250
INTAKE METHOD: Piston ported
OPERATING RPM:

Poulan Pro Model: 210
INTAKE METHOD:
OPERATING RPM: 12,600 free speed

Poulan Model: 2000
INTAKE METHOD: Reed valve
OPERATING RPM: 7,500

I was told by some that when setting the RPM at WOT on an engine that utilizes a reed valve that I should have the cutters in some wood to achieve the adjustment of engine speed at "OPERATING RPM". I was warned that adjusting it on the bench, chain installed, WOT and at "free speed"...I could damage the reed valve.
My sources said that bench adjustment, chain installed, WOT and at "free speed" would be the appropriate method for a saw that is piston ported.

Here is what the collectors corner states about the Stihl 010 AV:

Stihl Model: 010 AV
INTAKE METHOD: Piston ported
OPERATING RPM:

I don't know...you tell me. If grantwolland says that his 010 AV has a reed valve then perhaps the collectors corner is just wrong.
Got trees?

 

[Elmore]

...I was told by some that when setting the RPM at WOT on an engine that utilizes a reed valve that I should have the cutters in some wood to achieve the adjustment of engine speed at "OPERATING RPM". I was warned that adjusting it on the bench, chain installed, WOT and at "free speed"...I could damage the reed valve...Got trees?

Sounds like a PITA...I may keep my little tophandle Poulan on the bench when I adjust the carb.

 

[wood4heat]

yes, it is safe to run any saw on 50:1 with modern oils, those thicker mixes are remnant from ages when it was common to mix MOTOR OIL with gas...

Even with modern oils I would stick with the oil ratio recommended by the saw's manufacturer. I agree you will get as good if not better protection at 50:1 with a modern oil but in an older motor the oil can actually help seal the rings. Also because premix displaces fuel unless you readjust your carb less oil will richen your air/fuel mix. I realize were only talking about a difference of 40:1 to 50:1 which is probably too insignificant to affect either of these I just thought it was interesting info.

 

[wood4heat]

Well, this 010 AV has a reed valve under the carb. what is piston porting as you mentioned? is it safe to run a 50:1 synthetic mix (i.e. Stihl brand) in older saws that called for something else? what's your experience? I've already had sticker shock on buying a new cylinder, prefering to hone the existing one. so in my opinion richer is better to protect my older saws(most of what I own) I use a 40:1 synthetic in most of them. what's your experience with premium fuel (93 octane) does the additives in the premium fuel (cleaner etc.) screw with the mix?

Someone correct me if I'm wrong but in the motocross world there are piston port motors and case inducted motors. On a piston port motor the intake is bolted to the cylinder where as a case inducted motor the intake is bolted to the crankcase. Piston port motors usually have better midrange power and case inducted motors have better top end. I believe they call it piston port because there is a window on the intake side of the piston to allow the intake charge into the crankcase when the piston reaches the bottom of its stroke.