Air cooled engine - shut off/ start up

carpetcleaner

Member
Joined
Mar 5, 2010
Messages
520
Location
Gilbert, AZ
Name
Rob Litwin
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?
 
Joined
Mar 29, 2008
Messages
9,345
Location
Hawaii
Name
Nate W.
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..
 

Dolly Llama

Number 5
Joined
Oct 7, 2006
Messages
30,495
Location
North East Ohio
Name
Larry Capitoni
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.
 

Andy

Member
Joined
Feb 5, 2016
Messages
950
Location
No Where
Name
Doesn't Matter
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.
 

Jim Williams

Member
Joined
Oct 8, 2006
Messages
1,462
Location
Bynum N.C.
Name
Jim Williams
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.
 
Last edited:
  • Like
Reactions: ronbeatty

Onfire_02_01

Member
Joined
Jan 2, 2016
Messages
767
Location
Minnesota
Name
Jeremy Gray
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.
 
  • Like
Reactions: ronbeatty

Dolly Llama

Number 5
Joined
Oct 7, 2006
Messages
30,495
Location
North East Ohio
Name
Larry Capitoni
I never run my Kohler at full throttle My last engine lasted well over 10,000 hours.


10K with no major repairs??

I had an old cast iron Kohler that went 6000 hours
Had a Command Pro that went 4200 before sucking a valve

never heard of any air cooled going 10K without rebuild though

..L.T.A.
 
  • Like
Reactions: jcooper

Jim Williams

Member
Joined
Oct 8, 2006
Messages
1,462
Location
Bynum N.C.
Name
Jim Williams
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.
 
  • Like
Reactions: jcooper

jcooper

Member
Joined
Oct 7, 2006
Messages
3,232
Location
IL
Name
Jerry Cooper
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!
 
Joined
Oct 25, 2016
Messages
2,802
Location
Montana
Name
Swani
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.
 
  • Like
Reactions: BIG WOOD

BIG WOOD

MLPW
Joined
Feb 4, 2016
Messages
13,158
Location
Georgia
Name
Matt w.
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
 

carpetcleaner

Member
Joined
Mar 5, 2010
Messages
520
Location
Gilbert, AZ
Name
Rob Litwin
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.
 
  • Like
Reactions: BIG WOOD
Joined
Jul 15, 2011
Messages
470
Location
New Port Richey, FL
Name
Ross Martin
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.
 

Dolly Llama

Number 5
Joined
Oct 7, 2006
Messages
30,495
Location
North East Ohio
Name
Larry Capitoni
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.
 

Jimmy L

Member
Joined
Oct 7, 2006
Messages
15,162
Location
Ne
Name
Jimmy L
1/2 throttle with no hoses, then bump up full throttle and attach hoses.

Reverse on shut down.

I even do this for my PTO.
 
  • Like
Reactions: SamIam

Latest posts

Back
Top Bottom