Kohler K532 - Intermittent Issues (Fuel?)

[TheYard]

I've recently purchased a Bolens HT 20 with a Kohler K532 engine (prior owner indicates that it's recently new carb, but who really knows), and it's been a bit flakey. It either runs strong, or not at all (won't start), and I'm hoping someone here can point me in the right direction.

The first time I had issues I had been using the machine for about 2 hours, when it just died. If I left the machine alone for a couple of minutes, I could restart it, but it would die after 10 seconds or so.

I let the machine sit for about a week, and then went to check the carburetor settings - and the air filter was pretty dirty. I checked the fuel pump by pulling the fuel line to the carb and turning the engine over with the spark plugs disconnected, and there were short spurts of fuel pushing out of the fuel line. Wasn't a fire hose, but probably doesn't need to be, right?

After the new air filter came in, I opened things up again and bottomed out the main fuel mixture adjustment (gently), and backed it out an extra half turn past where it was originally (2.5 turns). Voila - the engine started. Used it for several hours that day.

A few days later, I used it for a couple of hours, turned it off to do something, and it wouldn't start again.

Yesterday, I used it for an hour, and shut it down. This morning, I couldn't start it. Adding fuel straight down the carb directly would cause the engine to start, and then die. Various combinations of choke and throttle didn't seem to make a difference.

I could definitely use a push in the right direction - anyone have some suggestions?

 

[CalG]

Sometimes My HT-23 is a poor starter. Lots of times it will crank until the battery goes weak. I put the charger on and walk away. Come back 10 minutes later, and the thing starts before the starter is heard. I then do the tractor work needed and put the charger back on for a couple of hours after the tractor is parked again to make up for the whimpy charging current.

I had trouble with the fuel pump years ago, and the symptoms were consistent with no fuel delivery, in that the engine would always start and run on gasoline squirted down the carb bore. I even keep gas in a squirt bottle for when I just don't want to wait. I installed an electric fuel pump that runs whenever the key is on. But it is plumbed through the mechanical pump. The issues remain with that boost pump. Next time the engine tin comes off, I plan to replumb the fuel line from the electric pump directly to the carb with an over volume return line to prevent vapor lock. Similar to automotive practice.

It might be the needle and float sticking closed and the fuel in the float bowl getting low and not refilling. Or floating debris clogging the jets.
But the first symptom suggests flooding, which puzzles me when it starts up with a squirt down the carb.

Yup, Good topic for me.. I hope there is a solution. Someone please tell me it's electrical ;-) It might be, the push on connector on the coil is original .....

 

[TheYard]

Sometimes My HT-23 is a poor starter. Lots of times it will crank until the battery goes weak. I put the charger on and walk away. Come back 10 minutes later, and the thing starts before the starter is heard. I then do the tractor work needed and put the charger back on for a couple of hours after the tractor is parked again to make up for the whimpy charging current.

I had trouble with the fuel pump years ago, and the symptoms were consistent with no fuel delivery, in that the engine would always start and run on gasoline squirted down the carb bore. I even keep gas in a squirt bottle for when I just don't want to wait. I installed an electric fuel pump that runs whenever the key is on. But it is plumbed through the mechanical pump. The issues remain with that boost pump. Next time the engine tin comes off, I plan to replumb the fuel line from the electric pump directly to the carb with an over volume return line to prevent vapor lock. Similar to automotive practice.

It might be the needle and float sticking closed and the fuel in the float bowl getting low and not refilling. Or floating debris clogging the jets.
But the first symptom suggests flooding, which puzzles me when it starts up with a squirt down the carb.

Yup, Good topic for me.. I hope there is a solution. Someone please tell me it's electrical ;-) It might be, the push on connector on the coil is original .....

I've found some other references on the internet that seem to indicate that could be an intermittent fuel pump issue. I've ordered a rebuild kit for the pump along with a carb gasket kit. Next weekend I'll rebuild the pump, and if that doesn't work, then I'll pull the carb and check the bowl float etc.

 

[zimcocomp]

Sometimes My HT-23 is a poor starter. Lots of times it will crank until the battery goes weak. I put the charger on and walk away. Come back 10 minutes later, and the thing starts before the starter is heard. I then do the tractor work needed and put the charger back on for a couple of hours after the tractor is parked again to make up for the whimpy charging current.

I had trouble with the fuel pump years ago, and the symptoms were consistent with no fuel delivery, in that the engine would always start and run on gasoline squirted down the carb bore. I even keep gas in a squirt bottle for when I just don't want to wait. I installed an electric fuel pump that runs whenever the key is on. But it is plumbed through the mechanical pump. The issues remain with that boost pump. Next time the engine tin comes off, I plan to replumb the fuel line from the electric pump directly to the carb with an over volume return line to prevent vapor lock. Similar to automotive practice.

It might be the needle and float sticking closed and the fuel in the float bowl getting low and not refilling. Or floating debris clogging the jets.
But the first symptom suggests flooding, which puzzles me when it starts up with a squirt down the carb.

Yup, Good topic for me.. I hope there is a solution. Someone please tell me it's electrical ;-) It might be, the push on connector on the coil is original .....

You installed an electric fuel pump in line with the engines pump. Did you try turning off the electric pump and run engine? This would require a pump that allows flow through when off. If you were successful could you tell me the brand? I have a Bolens QT16 and I want to use the pump as a primer. I turn off the fuel and let the engine run out and starting is difficult. My engine is a Kohler KT17. TIA

 

[CalG]

You installed an electric fuel pump in line with the engines pump. Did you try turning off the electric pump and run engine? This would require a pump that allows flow through when off. If you were successful could you tell me the brand? I have a Bolens QT16 and I want to use the pump as a primer. I turn off the fuel and let the engine run out and starting is difficult. My engine is a Kohler KT17. TIA

I ended up bypassing the mechanical pump completely. Went with the low pressure electric pump from the local auto supply (2-3 psi IIRC). I can't recall the brand atm. Works just fine now. Starts reliably. All Good.

 

[Chopper 155]

I've recently purchased a Bolens HT 20 with a Kohler K532 engine (prior owner indicates that it's recently new carb, but who really knows), and it's been a bit flakey. It either runs strong, or not at all (won't start), and I'm hoping someone here can point me in the right direction.

The first time I had issues I had been using the machine for about 2 hours, when it just died. If I left the machine alone for a couple of minutes, I could restart it, but it would die after 10 seconds or so.

I let the machine sit for about a week, and then went to check the carburetor settings - and the air filter was pretty dirty. I checked the fuel pump by pulling the fuel line to the carb and turning the engine over with the spark plugs disconnected, and there were short spurts of fuel pushing out of the fuel line. Wasn't a fire hose, but probably doesn't need to be, right?

After the new air filter came in, I opened things up again and bottomed out the main fuel mixture adjustment (gently), and backed it out an extra half turn past where it was originally (2.5 turns). Voila - the engine started. Used it for several hours that day.

A few days later, I used it for a couple of hours, turned it off to do something, and it wouldn't start again.

Yesterday, I used it for an hour, and shut it down. This morning, I couldn't start it. Adding fuel straight down the carb directly would cause the engine to start, and then die. Various combinations of choke and throttle didn't seem to make a difference.

I could definitely use a push in the right direction - anyone have some suggestions?

 

[Chopper 155]

on your HT 20... on dying,,,, for starters on a hot tractor , if you use alchol gas( ethenol) , vaporizes in your Manifold and does not fire correctly, WHen it is HOT.... so get premium , non alchol premim gas. ONLY !
2. the Harley Coil on there ,that lost spark, it will get hot,and quit firing, so cool it down. ( to cool it down put two bags of ice around the Coil. and then see if it starts...
3. other wise your Problem on it can be anything from fuel lines, to Carburator, to a fuel pump. being DIRTY!

Hope this helps , start digging into it.
Chopper 155

 

[Williy]

I had a cub cadet fuel pump lost vaccum so
got an amazon special $10 fuel pump removed
old fuel pump installed electric one put choke to
full turn key starts first crank every time. Also
put clear plastic hose with filter and shut off in
line from tank to pump. Didn't feel like trying to
find out why it lost vaccum

willy

 

[CalG]

just because this topic has reappeared, I have always wondered if the fuel pump arm or cam lobe wearing thin is part of the problem.

The pumps are hard to find to get a new arm, and a pump kit won't solve any issues if it's mechanical.
A worn cam lobe could be repaired with weld build up, but at a cost.

I bring this up, because I have heard of such wear in automotive practice. older rigs for sure. Like the K532