Too much start/stop = overheat?

[FGZ]

I was under the impression that an air-cooled engine needed a little time under no load in order to cool down a bit (~20 seconds?) before you shut it off after you have been working it hard. This is one reason I hate running out of fuel in the cut, the other reason being that the last few strokes of the piston don't have fuel/oil there to lubricate.

My question is regarding a lot of wood I have to cut to different length on a jig. I do one cut, stop, reload jig. I have been stopping the saw during reload to save fuel, am I damaging it if I don't give it time to cool down?

 

[jus2fat]

I don't understand your question..??

How long does it take to change your jig..less than a minute..or 2-3+ minutes??

If less than a minute..why not just let it idle..you not using much gas at idle..!!

I don't think you're damaging it..it's not getting too very hot to do one cut.

Also..you're NOT talking about using that MS362 for ripping..are you..??

J2F

 

[67L36Driver]

From what I can tell by the outside appearence of the muffler (oily or dry), saws run relatively cold when not under load. Under load at WOT you can watch the excess oil burn off the muffler. A long time at idle the oil builds up again.

Just let it idle, it won't hurt a bit.

 

[CentaurG2]

I don’t warm them up and I don’t cool em down. Must start a 200T about 100 times a day. I have taken them out of the cut so hot that they are stihl smoking. Get about 2 years out of one before it is dead. Throw it away and get another. It will be paid off by the end of the first job. People worry way too much about chainsaws.

 

[CTYank]

I was under the impression that an air-cooled engine needed a little time under no load in order to cool down a bit (~20 seconds?) before you shut it off after you have been working it hard. This is one reason I hate running out of fuel in the cut, the other reason being that the last few strokes of the piston don't have fuel/oil there to lubricate.

My question is regarding a lot of wood I have to cut to different length on a jig. I do one cut, stop, reload jig. I have been stopping the saw during reload to save fuel, am I damaging it if I don't give it time to cool down?

How's that? Whoever gave you the idea that the oil all over the innards of the engine goes away totally and instantly when there's no more mix coming in with the air? Purest nonsense.

Doesn't hurt it at all to let it cool @ fast idle for a few seconds after working hard. Some of us don't see saws as throw-aways. Most saws I run will "tell" you that fuel's running out, and still run for some seconds under no load.

 

[FixNstuff]

I agree with the just let it idle concept. It will help keep the saw at running temp and save your starter from more wear. I do this with everything, air or liquid cooled. The only exceptions are diesels which I shut off if they'll be idling for longer than a few minutes.

I assume you wouldn't have asked the question if you just planned to throw it away after the job is done.

 

[zogger]

I don’t warm them up and I don’t cool em down. Must start a 200T about 100 times a day. I have taken them out of the cut so hot that they are stihl smoking. Get about 2 years out of one before it is dead. Throw it away and get another. It will be paid off by the end of the first job. People worry way too much about chainsaws.

For a lot of guys, chainsaws cost them money and it isn't a business tax deduction. They don't want to wear out their saws and throw them away in two years, they want them to last for 2-5 decades, even hand them down to the next generation.

I'll take your dead 200Ts if you don't want them!

 

[zogger]

I was under the impression that an air-cooled engine needed a little time under no load in order to cool down a bit (~20 seconds?) before you shut it off after you have been working it hard. This is one reason I hate running out of fuel in the cut, the other reason being that the last few strokes of the piston don't have fuel/oil there to lubricate.

My question is regarding a lot of wood I have to cut to different length on a jig. I do one cut, stop, reload jig. I have been stopping the saw during reload to save fuel, am I damaging it if I don't give it time to cool down?

Are you having to cut any place near electricity? If so get an electric chainsaw, then don't worry about it. When the trigger ain't pulled, they are OFF. The 400E poulan is 4 horse and gets pretty good reviews and is under one benjamin new, just a little. And stihl and husky and some others will sell you one for like three times that, and conversely you can get a bargain basement one for like ten bucks at most pawnshops and craigslist, the little remingtons, etc.

 

[FGZ]

I don't understand your question..??

How long does it take to change your jig..less than a minute..or 2-3+ minutes??

If less than a minute..why not just let it idle..you not using much gas at idle..!!

I don't think you're damaging it..it's not getting too very hot to do one cut.

Also..you're NOT talking about using that MS362 for ripping..are you..??

J2F

I was worried that stopping the motor right after a full throttle cut overheats it. But yes it takes me more than a minute to change the jig, and the last time I let it idle between cuts ate a tank of fuel way faster than I thought it should.

I agree I'm probably not damaging it, just wanted more opinions.

Yes I'm using my MS362 for this, only running saw I have. Too big? Too little? I like it :msp_thumbup:

How's that? Whoever gave you the idea that the oil all over the innards of the engine goes away totally and instantly when there's no more mix coming in with the air? Purest nonsense.

Doesn't hurt it at all to let it cool @ fast idle for a few seconds after working hard. Some of us don't see saws as throw-aways. Most saws I run will "tell" you that fuel's running out, and still run for some seconds under no load.

Just my misconception. Since fuel and oil are one in the same, running out of fuel meant no lubrication either. You're saying it's not bone dry the instant I run out of fuel, makes sense to me.

And several times I have run out of fuel really quickly, without any prior warning. This will probably remedy itself as I get more time on the saw.

I agree with the just let it idle concept. It will help keep the saw at running temp and save your starter from more wear. I do this with everything, air or liquid cooled. The only exceptions are diesels which I shut off if they'll be idling for longer than a few minutes.

I assume you wouldn't have asked the question if you just planned to throw it away after the job is done.

That's exactly backwards of what I have always thought about diesels. They circulate WAY more air than gassers and are happy to idle all day long without overheating, which is why I thought big rigs and most diesel pickup drivers let them idle most of the downtime unless shutdown is required for refueling. I don't disagree with your methods, just a different mindset on my part.

Are you having to cut any place near electricity? If so get an electric chainsaw, then don't worry about it. When the trigger ain't pulled, they are OFF. The 400E poulan is 4 horse and gets pretty good reviews and is under one benjamin new, just a little. And stihl and husky and some others will sell you one for like three times that, and conversely you can get a bargain basement one for like ten bucks at most pawnshops and craigslist, the little remingtons, etc.

Good point! I'm just out in the backyard, I'll have to look into picking up an electric when I come across a good deal.

 

[PLMCRZY]

I agree with the just let it idle concept. It will help keep the saw at running temp and save your starter from more wear. I do this with everything, air or liquid cooled. The only exceptions are diesels which I shut off if they'll be idling for longer than a few minutes.

I assume you wouldn't have asked the question if you just planned to throw it away after the job is done.

Well that's dumb especially if it's a turboed diesel. Turbo needs time to cool down after being run hard. I have a turbo timer on my truck that keeps it running 5 mins after I turn the key off.

 

[mecreature]

I let a saw idle down a bit after running it in the cut. Slightly rich idle should only help this.
I dont like to run a saw or anything out of fuel completely for various reasons.

JMO

 

[FixNstuff]

That's exactly backwards of what I have always thought about diesels. They circulate WAY more air than gassers and are happy to idle all day long without overheating, which is why I thought big rigs and most diesel pickup drivers let them idle most of the downtime unless shutdown is required for refueling. I don't disagree with your methods, just a different mindset on my part.

Diesels are fine to run constantly under load but when they idle for extended periods they can run too cool which causes incomplete combustion which in turn can cause the unburned fuel to run down the cylinder walls and dilute the oil. it also increases carbon buildup.

Diesel engine idling, from an authority: Detroit Diesel « BusBuilding.com

Edit: Just to be clear, I didn't mean a diesel should be shut down immediately and should have said after initial cool down to avoid excessive idling. As I mentioned, I let everything cool before shutdown if it's hot but I take extra care of diesels after that.

 

[jus2fat]

First off..FGZ...thanks for your reply..!!

The way I read the reply is that you are indeed using the MS362 as a ripping saw.

You definitely are doing the right thing to shut it down...but best to let it idle ~30 seconds.

I just hope you are sawing soft wood like pine..!!

If hardwood...you're using waay tooo small a saw..IMHO..!!

But it's your saw...and I wish you well with your ripping use of it.

J2F

 

[CentaurG2]

For a lot of guys, chainsaws cost them money and it isn't a business tax deduction. They don't want to wear out their saws and throw them away in two years, they want them to last for 2-5 decades, even hand them down to the next generation.

I'll take your dead 200Ts if you don't want them!

You are more than welcome to bid on the dead 200t(s) just like anyone else on ebay. I pay money for my saws too but they in turn, make me money. I don’t really know why else you would own a chainsaw if it was not making you money or heating your house. No need to anthropomorphize a chainsaw. It’s a tool and is as disposable as a pair of gloves. Start thinkin’ different and the tree you are felling might get the saw and you. If you cant afford to lose it over the side of a boat, did you really have any business owing it in the first place?? Funny, the diesel in the trucks tanks is worth more than a 200t.

 

[zogger]

You are more than welcome to bid on the dead 200t(s) just like anyone else on ebay. I pay money for my saws too but they in turn, make me money. I don’t really know why else you would own a chainsaw if it was not making you money or heating your house. No need to anthropomorphize a chainsaw. It’s a tool and is as disposable as a pair of gloves. Start thinkin’ different and the tree you are felling might get the saw and you. If you cant afford to lose it over the side of a boat, did you really have any business owing it in the first place?? Funny, the diesel in the trucks tanks is worth more than a 200t.

Oh, my mistake, I read it as you threw them away. Not interested in bidding on a clapped out, worn out saw on ebay. Clapped out worn out free for just shipping, sure, but pay money for it plus shipping? I don't think so.

Yes, saws make you money or make you firewood heat (or prune your trees, etc), I was just commenting on your attitude more than anything else, as in assuming everyone thought that way. Most guys would want their tools to last longer, but I fully understand your point of view as well, it's just a disposable cheap thing you use, and it is like I said, a business deduction for you as well, so you can afford to use them real hard, harder than proly harry homeowner might, "smoking in the cut" and so on.

Actually, I have never bought anything on ebay, don't even have an account, not real interested either. I just thought if they were headed to a dumpster they might be worth a look over to see what was salvageable or not.

I have way more time for sweat equity than I do cashola for purchasing new stuff. I buy real cheap junkers and fix them, that's all, I'm teaching myself to work on various saws now, sort of like..home schooling, to have a shop eventually, something to do soon as I switch from semi retired to..another form of semi retired. When I can't cut the mustard doing this physical farm labor stuff I do now. I just don't get many high end saws to practice on. Hmm..zero to none actually, except for old poulans, which are fun to work on really.

 

[PLMCRZY]

Diesels are fine to run constantly under load but when they idle for extended periods they can run too cool which causes incomplete combustion which in turn can cause the unburned fuel to run down the cylinder walls and dilute the oil. it also increases carbon buildup.

Diesel engine idling, from an authority: Detroit Diesel « BusBuilding.com

Edit: Just to be clear, I didn't mean a diesel should be shut down immediately and should have said after initial cool down to avoid excessive idling. As I mentioned, I let everything cool before shutdown if it's hot but I take extra care of diesels after that.

Tell a trucker that lol. Hell I've let my dodge idle all night when I had to sleep in it.

 

[FixNstuff]

Tell a trucker that lol. Hell I've let my dodge idle all night when I had to sleep in it.

It's your truck, do what you gotta do.

 

[Eric106]

Over the road trucks always get back up to full temperature the next time they are driven so the effects are not always as easily noticeable as they are in stationary engines. A diesel generator that is run for a long time at light load will definitely exhibit the effects described in that link and will be down for maintenance long before one run with a heavy load on it all the time will be.

-Eric

 

[naturelover]

Do know the computer controlled series 60 Detriots have a high idle that idles at 1100rpm or so, wasn't that for extended idling periods?

 

[PLMCRZY]

My cummins has it to. I use it for colder weather when I fire it up.