rectifier trouble shooting

[John c 156]

I've got what I think may be a rectifier given up 

 

1978 C101 8spd. K241 engine

 

battery not charging when running, 

12.65vdc when off

12.50vdc when running

12.35vdc running, headlights on

 

Battery is new in good condition, 

 

As close to a manual as I have is one for magnum series Kohlers, based on that I read the following:

 

Neither of the stator leads show shorted or grounded, about 2~3 ohms between them, and 34ish-vac output at full throttle. So I suspect the rectifier is at fault

 

is there a chart showing points to test and values to expect to troubleshoot the rectifier ?

 

I've got others laying around, so how interchangeable are they among other sizes engines

 

Also how can you determine what amperage the stator is rated for ?

 

Thanks, 

 

john

Edited 18 hours ago by John c

[ri702bill 12,136]

The rectifier housing must be grounded. Over time, oxidation builds up on the two mounting fasteners. Try jumping the housing to ground (not the fasteners) and retest. If it works, unmount it & clean the mounting area. Some of us add a ground wire between the rectifier housing and the screw head....

A freshly painted surface can cause issues too if the rectifier is attached to it...

[John c 156]

OK, I'll try that tomorrow, this old machine has plenty of rust all over it, so this may be something. 

 

So is there a way to tell the rating of the alternator ...that doesn't involve taking the flywheel off the engine ?

[Achto 31,826]

27 minutes ago, John c said:

So is there a way to tell the rating of the alternator ...that doesn't involve taking the flywheel off the engine ?

 

The spec number on the engine should help get you this information.

 

 

[John c 156]

the spec number on the engine is 46766d, anybody have a chart explaining what the number means ?

[953 nut 66,193]

The Spec. Number is located on the engine data plate, once you have that number you can be sure what parts are correct. Unless you are absolutely sure the engine is the one kit left the factory with you can't be sure just by using the year of the 

 

[gwest_ca-(File Mod) 12,240]

That specification number is assigned to identify how the engine was configured for the intended Kohler customer. The K241 engines have their own series of spec numbers.

When you go to the parts list you will see in this case there are two different stators illustrated in it but only one is listed in the list - the one that the spec number specified.

https://www.partstree.com/models/k241-46766-kohler-k-series-engine-made-for-wheel-horse-10hp-7-5kw/breaker-ignition-3/

Another way to identify the stator is to look at the location of the regulator terminals and their relationship to each other. The 10 amp and 15 amp are different.

 

Here is where the original illustrated parts lists started. Take your spec number with you

 

 

[953 nut 66,193]

                Your engine Spec Number shows it being a 1979 K-241 which is correct for the '79 C-101.

Going into the K-241 parts manual Groupe 18 (charging and ignition) we find the number 114 applies to all components related to charging for that engine.

You have a 15 amp charging system and the parts illustrated below are correct for your engine. We know that your stator is working properly based on the test you have done. Your voltage regulator / rectifier should be a 15 Amp unit. It has three tabs in an "L" pattern. I have attached a link to the parts manual for you.

Edited 2 hours ago by 953 nut
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[pfrederi 20,576]