half-throttle

[a. palmer jr.]

A lot of outboard motors are two cycle and I'm sure you can't run them at just idle and wide open. The thing is, chainsaws, like many other things you buy are a compromise. I'm sure that if people wanted to they could make the perfect carburetor for a chainsaw that would feed the correct mixture throughout the rpm range of the saw, but would they be able to sell a saw to the public that costs a great amount and may weigh quite a bit more and be bulkier than the old chainsaws? I suppose fuel injection on chainsaws isn't far away because it's already on motorcycles and 4 wheelers.

 

[SawTroll]

Why would'nt you run a saw WOT in most conditions?:monkey:

Ask the carvers - no other sane person would do it (I hope)....

 

[MS460WOODCHUCK]

Ask the carvers - no other sane person would do it (I hope)....

If we lived a little or should I say a LOT closer I would surely buy you a beer!

 

[tobster]

Why would'nt you run a saw WOT in most conditions?:monkey:

I was actually asking about two-strokes in general. (The subject came up as we watched a neighbor lug his weed eater for several minutes)

 

[CentaurG2]

I lug all of my weedwackers. Just enough whip to cut what I am aiming at and I have never had a problem except with my fs130. That thing is either on or off. No way to really lug it.

 

[eyolf]

It is true that diaghragm carbs meter poorly over their throttle range, and equipment like chainsaws usually are best adjusted for WOT. Way back in the old days this was really evident...in the days of Tillotsen H-series carbs...but things have improved.

Most of us try to run the L rich to aid in transition response, and we know that the low circuit continues to flow throughout throttle opening range, except in some carbs during extremely low vacuum situations at WOT, lugging the engine at low RPM.

This is foolishly asking for trouble. Overloading any engine is bad.

Many, many pumper carbs will actually flow a little too much fuel for light loads in mid range throttle situations. Many of us have used a chainsaw to cut brush, light limbs, and above-mentioned precision cutting, etc, where we wanted the control of part throttle, and learned to open the throttle up now and then to "unload" the engine.



I'm sure there are saws out there that won't follow this scenario, but I'd bet most of these saws are the cheap box-store models that most of US don't really care about anyway. If you're idling a 90cc saw with a 16" bar, cutting 3" saplings you'll experience fatigue and short plug life before you sieze it if the saw is in good mechanical shape and the carb is adjusted correctly.

 

[Winn R]

Jennings has a graph in his book with rpms on one axis and fuel delivery on the other.

With a 45 degree line he indicates proper mix. He then shows actual mix with a curved line snaking to the rich side at high and low rpms and lean in the middle range.

 

[Zombiechopper]

I lug all of my weedwackers. Just enough whip to cut what I am aiming at and I have never had a problem except with my fs130. That thing is either on or off. No way to really lug it.

Hmm. My 110 runs at low rpm really nicely. That was huge reason why I wanted a valved engine. It jusr works so well at part throttle

 

[056kid]

I use half throttle all the time, limbing, and nipping while falling & bucking.

All I know is my saw is fine and the smell makes me believe that the was runs excessively rich at less than full throttle...

 

[CentaurG2]

Hmm. My 110 runs at low rpm really nicely. That was huge reason why I wanted a valved engine. It jusr works so well at part throttle

I have it from numerous sources the fs110 does not have the same snappy on or off throttle that the 130 does. The fs130 works fine as a brushcutter or as a hedge trimmer. It does fine as a trimmer as long as you are the kind of fellow who likes to strip bark off trees, take out windows with rocks, destroy siding, sandblast, strip paint etc. It does not lack for power only control.

 

[Anthony_Va.]

There will always be those times when you have to run a saw at part throttle. I think that it should just be done when absolutely nessesary though. Even though alot of people get away with running them part throttle sometimes, including me, the fact is that it can be harder on the engine and should be kept to a minimum if possible.