K321 Compression Issue?

[CorkGuy12]

1986 JD 214 / K321

Bought used with a rebuilt engine

Approximately 300 hours on rebuilt engine

2020 Service @ dealer: Replaced Rear Sheave / Replaced deck and power belts / Lubed deck bushings / sharpened blades / Oil change / Adjusted deck height. Minor oil leak from bottom but not significant.

Mid 2021 Performance issue: Runs with no issues without PTO engaged. Engage PTO, and after 10 minutes, engine sputters, engine shakes, engine stalls, and engine recovered when choked but stalled immediately after choke removed. A bit of oil popping from oil tube.

Checked for spark, and when this issue occurs, spark remains constant.

Changed Capacitor, changed coil, changed plug (which had been the incorrect plug), changed points which were only 5 years old, changed plug wire..

Same issues after above was performed.

Early 2022: Changed carburetor.

After carburetor change, mower ran well with PTO engaged, for about 40 minutes and then engine sputters, engine shakes, engine stalls, and engine recovered if choked but stalls immediately after choke removed. A bit of oil popping from oil tube. A slight bit of smoke from exhaust. Engine still starts and runs well without PTO engaged.

Shop where I bought the JD thinks it may be a compression issue.

How do I check compression on a K321 which has an Auto Compression Release Mechanism?

August 30 2022 update:

FWIW, I just ran a compression check, with a compression check tool. 120 PSI, 5 times. I don't have a compression problem.

Might this be a fuel pump issue, since I have gone from 10 minute run time to 40+ minute run time after installing a new carb?

 

[ILENGINE]

Two things that come to mind. the head bolts were reused during the rebuilt which can cause issues with temporary blowing the head gasket when hot and then resealing when cool. and the points are not set correctly. Timing to be correct has to be set with either a timing light or ohm meter and patience.

 

[CorkGuy12]

Two things that come to mind. the head bolts were reused during the rebuilt which can cause issues with temporary blowing the head gasket when hot and then resealing when cool. and the points are not set correctly. Timing to be correct has to be set with either a timing light or ohm meter and patience.

Points were checked and done by the dealer.

Timing? Why is this mentioend?

For the first 298 hours of use after rebuild, no issues. Are you saying the blots became loose and need to be retightened or are you indicating I should change the head gasket? Also, when the issue first appeared, it would run only 10 minutes before failure, and after installing a carb, it's now running 40-50 minutes before the probem shows up.

 

[Rivets]

On the K321 & K341 series engines I used to find that the points would start to float and the condenser would start to breakdown with age and the engine got too warmed up. Had a large construction company who had 30-40 fleet of these engines and the solution we came up with was to replace both the points and condenser every other year, as part of the spring tuneup. My Kohler support guy says that doesn’t make sense, but customer was happy to have the engine for a full year with no problems.

 

[CorkGuy12]

On the K321 & K341 series engines I used to find that the points would start to float and the condenser would start to breakdown with age and the engine got too warmed up. Had a large construction company who had 30-40 fleet of these engines and the solution we came up with was to replace both the points and condenser every other year, as part of the spring tuneup. My Kohler support guy says that doesn’t make sense, but customer was happy to have the engine for a full year with no problems.

Points are a real pain to access on my 214

 

[CorkGuy12]

Two things that come to mind. the head bolts were reused during the rebuilt which can cause issues with temporary blowing the head gasket when hot and then resealing when cool. and the points are not set correctly. Timing to be correct has to be set with either a timing light or ohm meter and patience.

FWIW, I just ran a compression check, with a compression check tool. 120 PSI, 5 times. I don't have a compression problem. Might this be a fuel pump issue, since I have gone from 10 minute run time to 40+ minute run time after installing a new carb?

 

[ILENGINE]

FWIW, I just ran a compression check, with a compression check tool. 120 PSI, 5 times. I don't have a compression problem. Might this be a fuel pump issue, since I have gone from 10 minute run time to 40+ minute run time after installing a new carb?

On occasion the lobe on the camshaft that drives the fuel pump will wear down limiting the pumping ability of the pump. Have added an electric pump a couple times over the years on various riders.

 

[CorkGuy12]

On occasion the lobe on the camshaft that drives the fuel pump will wear down limiting the pumping ability of the pump. Have added an electric pump a couple times over the years on various riders.

I've been reading about that issue the past hour or so as that seems to be my problem, a 36 year old pump. Can you point me toward a site with the electric pump you've used, or something similar? And if yes, I would need some wiring diagrams.

 

[ILENGINE]

@CorkGuy12 I have a local auto parts store that stocks the low pressure fuel pumps, but several available on like Amazon for around $10. Just need to find a key on power source to connect the red wire for the pump and the black wire just goes to ground,

 

[CorkGuy12]

@CorkGuy12 I have a local auto parts store that stocks the low pressure fuel pumps, but several available on like Amazon for around $10. Just need to find a key on power source to connect the red wire for the pump and the black wire just goes to ground,

Can you point me to at least a name of what to look for on Amazon? Thanks