Cv730-0006

[Coleevans321]

I have a kohler motor powering a prodrive boat motor. Customers problem is no power under load. I have cleaned carb and installed new heads, valves, intake gaskets, head gaskets, and spark plugs. Still has not corrected the problem. Used kohler spark testers to test ignition coils and they tested good. Leak down test was good and 175 compression on both cylinders. Idles like a new motor but at high idle small amounts of black smoke can be seen coming out of muffler. Raw fuel? Any idea of where to look next would be appreciated.

 

[Rivets]

Had this same problem about a boat motor drive powered by Briggs. Found a bad bearing in the drive unit, which caused a high load when it got warm. Just a thought.

 

[ILENGINE]

Did you use the standard spark testers or the HEI spark testers. Makes a different in some cases. i believe that engine calls for the HEI testers

 

[Coleevans321]

Had this same problem about a boat motor drive powered by Briggs. Found a bad bearing in the drive unit, which caused a high load when it got warm. Just a thought.

This style motor has your typical pto switch to activate the propeller. If the pto is not engaged and you increase rpms and have the same outcome would that still be the problem?
Thanks

 

[Coleevans321]

Did you use the standard spark testers or the HEI spark testers. Makes a different in some cases. i believe that engine calls for the HEI testers

Not exactly sure on the type spark tester this is. Kohler part # 25 455 01-s. Let me know if this is not correct and I will try again with the correct spark plug tester.

 

[ILENGINE]

Kohler use to have a tester for CDI ignition systems and a different one for non CDI ignition systems. I have found one source that shows the 25 455 01 for non CDI systems and another source saying that the 25 455 01 is used with all ignition systems. and both are Kohler sources. The CDI Kohler test that I have says HEI on it. And they always said that if you use the wrong tester it will give a false positive.

It does appear that Kohler has discontinued the HEI tester so it looks like you have the correct tester. It looks like the current version of the one that I have is this one

Amazon.com: OTC 6589 Electronic Ignition Spark Tester: Automotive

Buy OTC 6589 Electronic Ignition Spark Tester: Ignition Testers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

 

[Coleevans321]

Kohler use to have a tester for CDI ignition systems and a different one for non CDI ignition systems. I have found one source that shows the 25 455 01 for non CDI systems and another source saying that the 25 455 01 is used with all ignition systems. and both are Kohler sources. The CDI Kohler test that I have says HEI on it. And they always said that if you use the wrong tester it will give a false positive.

It does appear that Kohler has discontinued the HEI tester so it looks like you have the correct tester. It looks like the current version of the one that I have is this one

Amazon.com: OTC 6589 Electronic Ignition Spark Tester: Automotive

Buy OTC 6589 Electronic Ignition Spark Tester: Ignition Testers - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

Alright this carburetor has an accelerator pump mounted to the bowl of the carb. Carb and accelerator pump have new rebuild kits in both. If I remove the hoses connecting the accelerator pump to the carb (bypassing the accelerator pump) then the motor runs fine.

 

[StarTech]

This is strange so I wrote to one of my distributors as the IPL is showing a carburetor repair kit for a non-accelerator pump even online search reveals an accelerator pump version of the carburetor. even the Kohler carburetor reference manual is not showing an accelerator pump for the 24 853 90-S carburetor.

Hopefully they can clarify what going on here.

 

[ILENGINE]

Didn't happen to not install the restrictor valve inside the rubber tube on the accelerator pump did you.

 

[Coleevans321]

Didn't happen to not install the restrictor valve inside the rubber tube on the accelerator pump did you.

Yeah restrictor is in tube from accelerator pump. After bypassing accelerator pump motor runs great with no load but under load motor fails to produce enough power to get the boat to plain out. I also have a new carb coming to see if there is a problem with the rebuild. Will be Wednesday before it shows up. Will keep everyone posted. Never been defeated by a motor before.