Better to idle or shut off and on?

[BillyDBrown]

One of my current applications involves a lot of starting and stopping. When temporarily between usage, with the health of the machine in mind, when ought one draw the line between leaving the machine idle vs. turning it off and back on again when needed? My understanding is that diesels are better off left running and 2 stroke engines better off shut off and on but what about the BCS 749 with Honda GX390 gas engine? :scratchchin:

 

[tomplum]

In most cases once the engine has come to operating temperature, you would do best to shut the engine off. For stops under 2-3 minutes, leave it run.

 

[leonz]

If you can afford it, purchase a catalytic converter for the honda engine as the EPA regs make the exhaust really really nasty.
I had to buy one for my commercial firewood splitter and I wish I had done it sooner than I did.

 

[ottawarob]

I'd leave it idle if you're cycling it on and off, but... from what I've heard (could be wrong), one of the biggest wear and tear's on an engine is on start, when oil hasn't started lubricating everything yet. That said, if it's been off for a minute... things are probably still lubricated? Or maybe not? :/

 

[newbury]

This conundrum has bugged me for years. In Germany in the late '80's I was impressed how the drivers would turn their engines off when stopped for a train that routinely only lasted a minute or so. Now it seems many new vehicles come with auto stop/start.
Perhaps the advances in lubrication have made it so it's not an issue.

 

[prof fate]

at our school bus garage we're told let them run (big diesels) - 1/2 hour even. Saves on the starter motor is the oft mentioned reason. Not sure what if any effect it has on the battery.

If a tractor can go 5000 plus hours, does it matter one way or the other if we'r eonly doing 50-100 hours a year? it's a 50 plus year timeframe to hit 5,000 hours.

Does it save fuel? the environment? More running means changing oil more often?

I personally hate idleing in my car/truck, needed at times when hooking up trailer, strapping down, etc. Same for the tractor - changing implements I just let it idle (diesel). When doing yard work with my gas mower and a trailer I/m torn...loading trailer I often turn it off, unloading is faster so i let it run.

 

[ottawarob]

Glad I'm not the only one that wonders this.

BillyDBrown, I'd imagine if you throttle down, the engine isn't actually using that much gas - I'd probably just throttle it right down to idle and keep it going.

 

[smstonypoint]

My understanding is that diesels are better off left running and 2 stroke engines better off shut off and on ..... :scratchchin:

Just curious. I have heard (read?) that "working 2-cycle engines hard" helps in reducing carbon buildup in their exhaust ports/mufflers, thus idling would promote that buildup. But would frequent stopping/starting (and not working the engine hard for an extended time) promote carbon buildup?

Steve

 

[Gary Fowler]

I hardly ever stop the engine on my tractor when doing a quick off the tractor job. Lots depends on the length of the job though and whether or not I am running the AC to keep things cool. On my little Kubota, I will shut it down if the job will take more than 5 minutes.
As for wear and tear of the starter vs engine, I don't think most CUT owners have to worry much about wearing out the engine or the starter in their lifetime.

 

[RalphVa]

There's a safety aspect, too. If you're stopped on a slope, it'd be better to shut the engine off and put it in gear as well as have the brake on if getting off the tractor.

For my cars and pickup, if I'm stopped where I know a light pattern and know it's a long one, off goes the engine. Stopped to pickup books at the drive-through at the library. Engine off until I get the books. No sitting in vehicle with AC or heater on if wherever you're going isn't open yet. Shut the engine off.

Ralph