Choke engine on hot restart?

Cut up

Forum Newbie
Joined
Mar 10, 2024
Threads
2
Messages
3
Kohler 22 HP, M/N KT725-3027, Manufactured 10/2014 with 7500 hours.
Before replacing parts and servicing it would start without choking when hot.
Now on rare occasions it will start but most of the time I have to choke it and it starts after a few revolutions.
1. Replaced, coils, (original & 1 plug wire lead had cut in it from rubbing against sharp edge of housing).
2. Compression test, 105/115
3.Adjusted valves per specifications.
4. New air filter.
5. New fuel filter.
6. Changed oil & filter.
7. Changed transaxle oil.
8. Replaced crankshaft oil seal.
It makes full power with no hesitation in throttle movements.
I did see a post reply, “not unusual to have to choke engine on a hot start”.
I wouldn’t think that would necessarily apply to all engines?
Any thoughts?
Thanks
 

ILENGINE

Lawn Royalty
Joined
May 6, 2010
Threads
44
Messages
11,039
According to the service manual for your engine the compression is supposed to be a 160 psi minumum. So part of the issue may be the compression being low. And is that 7500 hours accurate. If so that engine is way past it designed lifespan, so somebody took good care of it, Most likely that is supposed to be 750.0 hours which is still a fair amount of hours.
 

Cut up

Forum Newbie
Joined
Mar 10, 2024
Threads
2
Messages
3
According to the service manual for your engine the compression is supposed to be a 160 psi minumum. So part of the issue may be the compression being low. And is that 7500 hours accurate. If so that engine is way past it designed lifespan, so somebody took good care of it, Most likely that is supposed to be 750.0 hours which is still a fair amount of hours.
If that’s the case I’m amazed at the power it still has, no smoke, no noise, does not use oil and always starts within a few revolutions and runs great.
I guess it’s possible that the prior owner(s)
could have rebuilt the engine?
 

Tiger Small Engine

Lawn Addict
Joined
Dec 7, 2022
Threads
3
Messages
1,342
If that’s the case I’m amazed at the power it still has, no smoke, no noise, does not use oil and always starts within a few revolutions and runs great.
I guess it’s possible that the prior owner(s)
could have rebuilt the engine?
Some engines require a very brief choke to start hot.
Your compression is on the low side. Keep an eye on oil and run it.
 

VegetiveSteam

Well-Known Member
Joined
Jun 1, 2022
Threads
1
Messages
453
Kohler 22 HP, M/N KT725-3027, Manufactured 10/2014 with 7500 hours.
Before replacing parts and servicing it would start without choking when hot.
Now on rare occasions it will start but most of the time I have to choke it and it starts after a few revolutions.
1. Replaced, coils, (original & 1 plug wire lead had cut in it from rubbing against sharp edge of housing).
2. Compression test, 105/115
3.Adjusted valves per specifications.
4. New air filter.
5. New fuel filter.
6. Changed oil & filter.
7. Changed transaxle oil.
8. Replaced crankshaft oil seal.
It makes full power with no hesitation in throttle movements.
I did see a post reply, “not unusual to have to choke engine on a hot start”.
I wouldn’t think that would necessarily apply to all engines?
Any thoughts?
Thanks
With the carbs being set so lean in the last 15 to 20 years, having to choke a warm engine was not necessarily the norm but it was certainly not unheard of. On engines that were affected by that scenario the issue was there from day one brand new. It wasn't typically something that developed over time. You could have a small amount of buildup in the carb passages that is just enough to make choking necessary but not enough to notice any normal running issues. A small air leak could do the same thing.

As far as your compression, you may want to check it again and make sure the choke and throttle plates are wide open. A typical Kohler twin under 125 lbs of compression normally lacks power and probably smokes some. It sounds like your engine runs strong so I feel those compression numbers almost can't be correct. But then again, if it's running strong and not using any oil, does a number even really matter?
 
Top