Air cooled engine - shut off/ start up

#1
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I was talking to another cleaner today as I was finishing at a house today. He told me that I was starting up and shutting off my machine wrong.

I start up without the vacuum hose connected, with the machine at low idle. I throttle up and connect the vacuum hose to the waste tank.

I shut down in reverse of start up and bring the machine down to low idle for a bit before turning the engine off.

He said that I should leave my machine at full throttle at all times. Start up and shut off without the vacuum hose connected, but never lower the throttle.

Is one way better? Why?
 
#2
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I've always started up my machine on low idle with the hoses connected.. Let it warm up for a minute or 2, then full throttle it.. Shutting down is where I bring the idle down for about 4-5 minutes, disconnecting the hoses and wrapping up before turning it off..

Whether it's right or wrong, fook if I know.. From the videos I'm seen, that's how I came to the conclusion..

I did hear other guys say you shouldn't run an AirCooled motor at half throttle.. Either idle or full throttle.. Something to do about torque curve, strain on the engine and the cooling of the engine..
 
#7
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start up at 1/2 throttle (1500-1800 rpm) with NO LOAD (meaning no vac hoses)

start up at mid RPM gets the oil pumping/circulating faster is why it's better than low idle

shut down;
Pull hoses and idle down to 1500 or so ..run for a minute or two then shut down .
I forget what the reason for the minute or two no load run time before shut down is for, but recall there is a valid reason for it

air cooled motors shouldn't be run under load at low/mid RPM due to lack of cooling.
They should be run at 80% to max RPM for most efficiency. cooling and longevity


..L.T.A.
 
#8
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Start at mid throttle with no load to make it easier on the starter. Does not matter after that when you hook the hoses up.
When shutting down, slow to mid throttle, remove vac hose to prevent back spin on the motor and to prevent blowing a head gasket, throttle to idle for a minute shut off.
 
#9
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I never run my Kohler at full throttle My last engine lasted well over 10,000 hours.

The Kohler reps just want you to run them hard so you'll have to buy a new engine every 3000 hours. And if you blow an engine under warranty, good luck getting them to replace it. They screwed me out of a lawn mower engine that was under warranty.
 
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#10
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I never run my Kohler at full throttle My last engine lasted well over 10,000 hours.

The Kohler reps just want you to run them hard so you'll have to buy a new engine every 3000 hours. And if you blow an engine under warranty, good luck getting them to replace it. They screwed me out of a lawn mower engine that was under warranty.
Warentys are only worth the paper they are printed on. No matter how closely they are followed you have always done something to void it.
 
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Yep. That baby fired up every day for 9 years. It probably should have been replaced about 2 years sooner because of a blown head gasket but she kept running.

I should probably have the water pump rebuilt. It's been running 13 years with no rebuild. I have to be sure and put the water line from the tank on top of the engine when I shut it down or it will lose prime and it's a pain to get it primed again.
 
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#14
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Yep. That baby fired up every day for 9 years. It probably should have been replaced about 2 years sooner because of a blown head gasket but she kept running.
I should probably have the water pump rebuilt. It's been running 13 years with no rebuild. I have to be sure and put the water line from the tank on top of the engine when I shut it down or it will lose prime and it's a pain to get it primed again.
Darn, seems like he's making up for the rest of us!

Had a Command Pro that went 4200 before sucking a valve
4200? I'll take it! That will get me another 2 years on my command pro, leaks a little oil, but I let that stop bothering me after finding out the cost of a new installed engine!
 
#16
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I was talking to another cleaner today as I was finishing at a house today. He told me that I was starting up and shutting off my machine wrong.

I start up without the vacuum hose connected, with the machine at low idle. I throttle up and connect the vacuum hose to the waste tank.

I shut down in reverse of start up and bring the machine down to low idle for a bit before turning the engine off.

He said that I should leave my machine at full throttle at all times. Start up and shut off without the vacuum hose connected, but never lower the throttle.

Is one way better? Why?
My mechanic at Interlink told me the same thing, but I can't bring myself to run a cold engine at full throttle.
 
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#17
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My friend has a big pressure washer on a trailer with a briggs 2cylinder engine on it. It doesn't have a throttle control. He cranks it up and turns it off at full throttle. It's about 10years old and he's been non stop in his pressure washing business. He's actually had to rebuild the water pump twice on the same engine
 
#19
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I googled it. It is an on going debate in any industry that uses air cooled engines.

Most of the engine manufacturers seem to recommend starting at 1/3 throttle with choke on. Turn choke off and slowly bring up to speed. For shutting down, remove load, slow to idle, turn off.

As long as the engine is properly maintained, it most likely doesn't matter how it is started or stopped. There seem to be long lasting engines either way.
 
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#20
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What I do (was told by mechanic where I bought machine).

Start up.
Low throttle, idle for a few minutes before any load.
I pre-spray with engine at idle.
Full throttle.
Lube blower with vac inlet completely shut off. (First job)
Attach vac hose.
Full throttle during operation - engine has governer.

Shut down.
Disconnect vac hose.
Run full throttle, no load for at least 5 minutes to dry blower.
Lube blower with vac inlet completely shut off. (Last job)
Idle for a minute or two and shut down.

Yes, there is no such thing as a Kohler warranty. The new 27hp that I bought is still not installed on my Judson. Back at Kohler after rep asked, "was this hit by lightning"? Started having problems after about 2 hours of operation. Been over 2 months.
 
#21
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Cold engine means cold oil.

Enough said.

nuff said?

lets explore this a bit more
cold oil doesn't lube less than warm .
and TMs are never colder than 32

now, if the viscosity is a little stiffer, how much longer will it take to pressurize the lube system at low idle compared to mid throttle ??

if you have a low oil shutoff by-pass to start up, you'll know which pressurizes the system sooner.
especially and in particular on cold start up (first of the day).
Once engine is hot (after the first job) it doesn't much matter .

It does when cold and first start up,,all the oil has run down over night .
Mid RPM pressurizes faster and decreases wear


think about it

..L.T.A.
 

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