Letting the saw run out of fuel ?

[OAP]

I have done this the last few times I,d finished work for the day and I did'nt need the saw again for a week or two ( the unleaded fuel not good for the saw while not in use) . Anyway the oldman was with us last Saturday and asked what I was doing, he said its bad for the saw ?
He has a lot of years and trees on the clock but is 10 years retired, so unleaded was not an issue in his day. Is he right ? or is it a case of the youth (I,m 42 ) today havent a clue.

[Reddog]

Well I am sure you will get lots of opinions, so here is mine. ;D

As long as the saw is not under a load, no damage will be done. If done while cutting, it could run lean at the end and over time cause cylinder and piston damage.

Thats my .02 cents.

[John Mc]

I agree with what Reddog posted. I let it run out at idled or maybe feathering the throttle at low RPMs to run the last of the fuel out. 

It's even more important to do this if you are cursed with gas blended with ethanol, as we are here in the USA. You don't want to leave ethanol laced fuel in the tank for any length of time. I see you are in Ireland. Do you have to deal with ethanol gas blends in your area?

John Mc

[chopperfreak2k1]

i agree, if it's not under load no harm should come of it

[kenskip1]

Well I have to chime in on this one. Just remember this, If you run the saw out of gas then, you are also running it out of lubrication (oil)! Ken

[boobap]

if no lube = no fuel. at an idle it is almost instant. there is enough residual to not cause anyharm...just my opinion aint got no facts to back this one...but i think common sense will prevail!

[OAP]

Well I have to chime in on this one. Just remember this, If you run the saw out of gas then, you are also running it out of lubrication
This is what the oldman says.
.
if no lube = no fuel. at an idle it is almost instant. there is enough residual to not cause anyharm...just my opinion aint got no facts to back this one...but i think common sense will prevail!
This is what I said. We have ethanol curse here too.

[ladylake]

I don't think letting it run out gets every drop of fuel out of the carb and lines and that little bit left will turn to crud in a hurry.   Steve

[Randy88]

Up until my Stihl saws I've never run a saw with a visable gas tank that you could see the level in and we ran them out all the time, about every time actually, and no harm was ever done to the saw, they usually lose power just a moment before and then drop rpms and quit so if its harmfull to do that we would have killed many thousands of saws over the years, now with the stihls, you can see the level of gas in the tank and its no big deal and you can quit before it runs out and that makes for starting easier as well.   As for doing it under a load, I've got a hard time believing it'll do harm without lubrication thing, yes theres a difference between half throttle and full bore under a high load but rarely do I worry about, we need to stop cutting large blocks and cut a few limbs because my saws about out of gas, you run them and when they start to lose power and sputter we shut them off about the same time they quit and fill them up and start sawing again.  I personally wouldn't worry about it at all, take it in stride and move on, I'm sure some here will fill volumes of the proper way to do things and how wrong I am but its worked for me over 30 years and may thousands of hours of use of saws. 

[John Mc]

A couple of problems with running it under load as it runs out of gas:

1) you are putting a heavier load on the engine, bearing surfaces & etc. at a time when lubrication is marginal

2) As the saw starts to run out of fuel, the engine will sometimes start running leaner. You can hear this sometimes: instead of just bogging and dieing, the engine starts to rev up and get a whining note to it... even when idling. Running an engine leaner at high RPMs can generate a lot of heat, and lead to detonation, rather than normal ignition.

You minimize both of these problems at idle/low RPMs and no load. Things are turning slower and with less pressure on bearing surfaces, so marginal lubrication is not as much of an issue. Also, the engine is not generating enough heat from combustion to burn things up or cause detonation, so the lean condition is not likely to be much of an issue.

[SwampDonkey]

Doesn't seem to affect a brush saw much, but who knows. Your cutting along in brush and I know of no one that takes his saw off and keeps checking his fuel level. They bog out anyway when starved for fuel. We run brush saws at a higher RPM than a chain saw. I'm on the 4th season on this brush saw I have and I cut 50-60 acres of brush a year. It would be more if I wasn't doing measuring and marking out as well.  ;D

[OAP]

It has happened me, but not very often that a saw runs dry with out me stoping it first and filling it.( unless I want it to ) Maybe its just me but I can hear when its on the last few drops, I can with a husky,stihl,partner or homelite anyway .

[Al_Smith]

If you want to run them dry ,the best thing is to start them up first. Shut them down and then dump  the fuel .Start it back up an let it idle until it dies .Now believe it or not a 60 cc Stihl 038 will idle for about 12 - 15 minutes on just what's in the carb . About drives you bonkers waiting  for it to sputter and die .