Early k161 slow crank issue. Possibly ACR

[OKcub]

Got my 1962 cub running recently but it takes a jump starter to get it cranking fast enough to start. Starts immediately with 60 extra amps runs great after starting. Does it hot or cold. Has new tested battery. Have checked positive battery cable where it goes to the back of the starter/generator and it has 12 volts when ground to the battery. Have checked battery ground cable where it goes into the back of the starter switch and it is grounding there.

Engine is difficult to turn by hand when it’s on the compression stroke. A compression test cold gave me 150 psi turning the engine by hand. So really good compression at low engine speed.


Is the ACR not supposed to be bleeding off cylinder pressure to assist starting?

I’m getting mixed signals on whether all k161’s use a compression release or a spake retarder to assist in starting. I read somewhere before 1963 Kohler used an ignition retarding mechanism to make it easier to start.

My engine does not have a removable cam gear cover to examine the cam gear.

A kohler manual I’ve found details how to adjust the older style compression release and the newer style. It says ALL Kohler series’s engines have ACR’s but I think the book is post 1963. It details that with the valve cover removed on the compression stroke turning the engine by hand you should be able to see the exhaust valve lift a little when the pistons 2/3 the up the cylinder. Mine does not do that. The next steps to diagnose your ACR are to remove the cylinder head and the oil pan which is fine but I don’t want to crack a good running engine apart to diagnose something I don’t even know is the issue.

My engine and my whole tractor are in 3-4 shades of yellow. Would not be surprised at all if the engine isn’t original or if it’s been rebuilt. If I’m NOT supposed to have a compression release type mechanism I would say I have an electrical issue. If I AM supposed to have a compression release mechanism would say it’s not working.


Does anyone have any advice from here? I’d like to figure out if my engine is SUPPOSED to have a compression release or not.

 

[mgonitzke]

As best I can tell looking at parts diagrams, the Original only had the spark advance cam.

 

[lpalma]

Got my 1962 cub running recently but it takes a jump starter to get it cranking fast enough to start. Starts immediately with 60 extra amps runs great after starting. Does it hot or cold. Has new tested battery. Have checked positive battery cable where it goes to the back of the starter/generator and it has 12 volts when ground to the battery. Have checked battery ground cable where it goes into the back of the starter switch and it is grounding there.

Positive battery cable goes to the push button switch, then to the starter generator, the ground goes from the - on the battery to the s/g mounting tab bolt, The way you write it is seems you are hooking up the battery incorrect.

 

[OKcub]

I’m typing things backward. The colors of my battery cables are switched for some reason. The battery is not hooked up backwards and apparently I need to proof read better.

I am getting good ground from the battery to the head of the lower mounting bolt for the starter generator. I am also getting 12v to the starter switch. I found an Original wiring diagram and all my other wiring matches it even to the color.

I removed the carb and it still cranks slow. So if I have no ACR and it’s still doing the slow crank without fuel it’s not the spark retard mechanism causing it to crank slow. Is there a way to test the starter/generators?

 

[kharvey]

Measure the battery voltage while cranking, I bet it's less than 12.

 

[tkhoffman]

I’m typing things backward. The colors of my battery cables are switched for some reason. The battery is not hooked up backwards and apparently I need to proof read better.

I am getting good ground from the battery to the head of the lower mounting bolt for the starter generator. I am also getting 12v to the starter switch. I found an Original wiring diagram and all my other wiring matches it even to the color.

I removed the carb and it still cranks slow. So if I have no ACR and it’s still doing the slow crank without fuel it’s not the spark retard mechanism causing it to crank slow. Is there a way to test the starter/generators?

Battery wire terminals may have been replaced. Dont worry about colors, worry about where they terminate from the battery. CUBS never had positive Ground systems, i dont think.

 

[Robert Payne]

Just replace the Starter/generator, Start from there,,, I had the same problem with my 1972 Cub 108 with the original starter,seemed to work fine with the belt off, but when the starter/generator belt was on it barely would crank the engine,,,also make shure the belt is not too tight...

 

[mgonitzke]

Is there a way to test the starter/generators?

A machine called a 'growler' is needed to check for open or shorted windings in the armature. Something a starter repair shop would have, if such a thing still exists.

I'd start by cleaning up the commutator and replacing the brushes before getting a whole new starter/generator.

 

[Bob H]

A machine called a 'growler' is needed to check for open or shorted windings in the armature. Something a starter repair shop would have, if such a thing still exists.

I'd start by cleaning up the commutator and replacing the brushes before getting a whole new starter/generator.

The "Auto Electric" shop in our part of the planet, just closed it's doors. I'm anxious for the auction to take place. Grounds are one thing I can't stress enough. Old metal, old paint, moisture, time, etc. can wreak havoc on anything that depends on good connections to operate. Unscrew the nuts, washers, etc. of each connection, being careful not to twist the studs in the process. Clean every part, preferably like a new Penny, I usually use a wire brush to break thru any stubborn layers of problem material. Reassemble using copper washers, if you have them, and tighten securely. Each, and every connection must be done, including the mounting brackets, to insure good current flow. I've fought equipment for years, and this is one area I'm very familiar with, trust me. Good luck.

 

[Robert Payne]

Like I said.....Just buy a new starter/ generator on E-Bay for $130- $150.. or take a chance on a used one for $75-$100...OR spend $15-$20 on a rebuild kit

 

[Bob H]

Just replace the Starter/generator, Start from there,,, I had the same problem with my 1972 Cub 108 with the original starter,seemed to work fine with the belt off, but when the starter/generator belt was on it barely would crank the engine,,,also make shure the belt is not too tight...

You say "Just replace the Starter/generator, start from there,,," I say that there are quite a few things that should be checked first, before throwing a couple hundred dollars at it, unless you just have oddles of dollars laying around, with no place to go. It's not grass cutting season yet, and this "forum" has the time, and ability, to help solve problems, sometimes with out spending any money at all. I like to help people learn more about the machines they're tinkering with, so that they can decipher when, and if, they need to replace parts, only as a last resort. Just my opinion.

 

[Robert Payne]

YES I SAID JUST REPLACE THE STARTER/GENERATOR!!! 50yr old parts don't last forever!! Once you know you have a good battery & starter THEN you can pull out your hair trying to figure out OLD COLOR FADED WIRES and diagrams if you still have a problem like a bad switch or starter solonoid which is still cost you money! why start buying a new switch, then a solonoid only to find out it's the starter that's bad.... BTW i'm 66yrs old and on a fixed income and DISABLED, So I check my major components first then work my way back, ALSO I buy JUNK RUSTY tractors and bring them back to LIFE

 

[mgonitzke]

Replacing parts randomly is by far the most expensive form of troubleshooting. All components can be inspected and checked to pinpoint issues, and then replace what is not functioning.

I will say though that replacing the 60-year old wiring harness would be money well spent. If there is corrosion under the insulation, the battery cables may look fine but may have high resistance under load, and this is not something that is easily measured.

 

[tkhoffman]

I agree to not Throw Parts at it...throw a test light or Volt meter at it instead. A little cleaning is Free. These gorls still have their Original starters, and generators. These were dropped off in my driveway this past summer. Both sat for many years. I got both running, new battery cables, the plunger starter solenoid and cleaning of the Starter Bendix on the 9N and new fan belt, Ignition Points and shining up the Brushes and contact points on the Generator on the 2N.
They are back to their homes. Husbands are happy, wives are furious. These old girls just keep running. A testament to what America can do IF they weren't sidetracked with crazy profits for junk.
1940 and 1943 Fords. 9N and 2N. The older versions of the more famous Ford 8N

 

[Bob H]

YES I SAID JUST REPLACE THE STARTER/GENERATOR!!! 50yr old parts don't last forever!! Once you know you have a good battery & starter THEN you can pull out your hair trying to figure out OLD COLOR FADED WIRES and diagrams if you still have a problem like a bad switch or starter solonoid which is still cost you money! why start buying a new switch, then a solonoid only to find out it's the starter that's bad.... BTW i'm 66yrs old and on a fixed income and DISABLED, So I check my major components first then work my way back, ALSO I buy JUNK RUSTY tractors and bring them back to LIFE

I am simply stating MY troubleshooting/repairing techniques, and I hope you can agree, to dis-agree, on any topic you choose. I'm sorry if I offended you, or in any way dis-regarded your "Right" to advertise your approach, for solving problems. We just "go about things differently" and that's what makes America what She is today. Be safe, Bob H, Southern Indiana p.s. You have some fine looking examples, of a variety of Tractors. Congrats.