Idling vs Starting/Stopping

[Alrashid2 171]

Hey yall, Al here again with another question haha. 

 

My new-to-me 312-8 tractor's main use will be to haul firewood up to my house every 2 weeks or so. The process will go like this:

 

• Drive tractor from shed to firewood racks: 1 min
• Park her and load up firewood cart: 10 minutes
• Drive it about 80 yards up to the house: 2 minutes
• Park, and unload firewood: 10 minutes
• drive back down to firewood, and repeat 3-4 more times

 

For the loading/unloading of wood in blue above, would it be better for the engine to run at idle while I'm parked, or to just turn it off and back on each time? Wasn't sure if keeping it running continuously was better or not.

 

If I let her run for the entirety, that'll be around 1.5 hours of total run time, but only around 15-20 minutes at full throttle and the rest idling. On the other hand, if I'm shutting her off each time, that'll only be 15-20 minutes of total run time but turning her off/on 8+ times. Not sure which is preferable... thanks all for the advice as always!!

Edited November 12 by Alrashid2

[gt14rider 765]

Turn it off. Not good to idle these old kohler k series. 

[953 nut 55,393]

Air cooled, splash lubricated engines will not be adequately cooled or lubricated if left idling for more than a minute or two.

Edited November 12 by 953 nut
fat finger

[Handy Don 12,281]

If the engine starts smoothly, the wear on the starter will be minimal. A tender on the battery during storage will assure that it doesn’t suffer from the short charging cycles.

[Alrashid2 171]

Thanks guys for your advice. So it seems the consensus is to not idle while loading/unloading.

 

Should I let the tractor run at a higher throttle then? Or just shut her down? 

[Handy Don 12,281]

7 minutes ago, Alrashid2 said:

Should I let the tractor run at a higher throttle then? Or just shut her down? 

Save the fuel and the planet. I shut down for stops longer than a minute or two.

[stevasaurus 22,771]

If you want to idle it, idle it at at least 1/2 of full throttle and run it at 3/4 to full.  For the length of time you are talking about, shut it down.  If it was one of 2 trips, I would idle at 1/2 throttle.  

   Another factor to consider...temperature.  I would shut it down in hot weather, 1/2 idle in cold.

[lynnmor 7,321]

Repeated starting and shutting down also contributes to engine wear.  The heating and cooling as well as the lubrication coming and going is the reason.

[Brockport Bill 1,668]

i am not an expert or mechanic -- but if it were my 312 -- if it were stored outdoors in winter temps ( you said in a shed ) and i did cold start to drive it only one minute i would let it warm for 1 - 2 minutes if below freezing to warm the engine oil and tranny oil before putting load on it -- but there are more qualified brains on here if that is necessary or a benefit?

[Alrashid2 171]

3 hours ago, lynnmor said:

Repeated starting and shutting down also contributes to engine wear.  The heating and cooling as well as the lubrication coming and going is the reason.

That is exactly why I posted this question - i kept finding both answers online!

4 hours ago, stevasaurus said:

If you want to idle it, idle it at at least 1/2 of full throttle and run it at 3/4 to full.  For the length of time you are talking about, shut it down.  If it was one of 2 trips, I would idle at 1/2 throttle.  

   Another factor to consider...temperature.  I would shut it down in hot weather, 1/2 idle in cold.

Thank you, will take this advice!

10 minutes ago, Brockport Bill said:

i am not an expert or mechanic -- but if it were my 312 -- if it were stored outdoors in winter temps ( you said in a shed ) and i did cold start to drive it only one minute i would let it warm for 1 - 2 minutes if below freezing to warm the engine oil and tranny oil before putting load on it -- but there are more qualified brains on here if that is necessary or a benefit?

Thank you, yes I will plan on warming her up for a few minutes while I get the cart around and attach it to the tractor. That should take me anywhere from 2-5 minutes. 

 

When warming up, I assume that shouldn't be done at idle speed? 1/2 throttle maybe? 

[8ntruck 7,034]

 I'll vote for warm up at 1/2 throttle.

 

Sunny and 40's here today.  I got my 14-8 out today for lawn sweeper leaf duty today.  I rolled him out of the shed, started him up, and let him run at 1/2 throttle while I pulled the lawn sweep out, tightened a loose bolt on it and hooked it up to the tractor. 

 

Noticed that the engine had a slight surge until it got up to operating temperature.  Looks like I'll need to go through the carb next spring.  Been several years since I've done that.

[Alrashid2 171]

Nice ok! I can do that. Am I safe to assume, in say 32F weather, warming up for 5 minutes at 1/2 throttle is enough before I go full throttle and work under load?

[kpinnc 12,175]

11 hours ago, Handy Don said:

Save the fuel and the planet.

Just my opinion, but if the overall use is as short as @Alrashid2 is talking about- shutting down and restarting multiple times probably dumps more fuel and dirtier exhaust than just running above half throttle for 20 minutes. Not to mention the wear and tear on the battery/ solenoid/ and starter. 

Might be best to shut down once each full trip, but I doubt your battery will last for 16 starts if you run the machine 5 minutes or less in between. 

[rmaynard 15,535]

Allow me to stray a little from small engines to cars. My son, daughter, and my wife all got new cars this year. All three have the feature that stops the engine when the car stops, then restarts when the accelerator is pressed. My son says that fuel efficiency on his car is higher than when it runs all the time. My daughter doesn't care but says if she could turn it off completely, she would. My wife's car is getting no better milage in the annoying "stop" mode. My opinion is that the cost of a new starter, or battery is much more than any fuel savings. I turn it off as soon as I start the engine.

 

Now back to small engines. My engines with oil slingers are all kept at an idle speed of 1100 to 1200 rpm, allowing for proper lubrication. Engine with oil pumps don't need to idle so fast. If I am going to be off the tractor for more than few minutes, I shut the engine off. Otherwise, I leave it running.

Edited November 13 by rmaynard

[Alrashid2 171]

Thanks for weighing in @rmaynard I had been told by others that these splash system engines should not sit at idle long. I believe my idle is 1200 rpm. Was that a typo in your post or do you find idle to be ok?

[rmaynard 15,535]

Idling at 1100 to 1200 rpm (Kohler recommended speed) is okay. 

[RED-Z06 2,221]

Ive never had any problems idling for extended periods beyond, if the tractor has a stack, you can get "cold stacking" where carbon can accurate in the pipe and you might get some carbon specks blow out on power up.  If you ever have the head off a worn K series and crank it over with the starter, you'll see oil accumulate on the lip of the piston, so even at low speed, oil is still moving around.

[clueless 3,006]

I think your over thinking about these tractor, they are tuff tractors with tuff engine. If you don't have the operator manual for your 312 go the the manual section here and download it. Kohler says to run these engines at full throttle, they also recommend throttling down for a few seconds (5 or 10) before shutting it down. I would think the designers and engineers at Kohler knew what was best for these engines, more than most of of us here. Idling, not idling, turn it off, let it run, best type of oil, don't even get me started on paint, it's kind of like the old Ford, Chevy, Dodge opinions and a certain area of the body, we all got one. For the most part your not going to hurt these things unless you don't change the oil and replace the air filter regularly, also oil is far better than it was when these were designed, you've gotten plenty of good information here, you do you.  Welcome to the addiction

[Alrashid2 171]

Thanks @clueless. I have a tendency to overthink things haha. I'm a scientist by trade and like to work based on data. I also have terrible luck, so didn't want to assume something about this engine only to totally destroy it! 

 

Will keep chugging along with all of the knowledge I've gotten from you all. Love this place! Thanks

[Handy Don 12,281]

2 hours ago, Alrashid2 said:

a tendency to overthink things

I suspect you might find some kindred spirits here.