K301 will not 'take' any ignition timing

[Greentored 3,201]

Thanks guys!

I DID notice a lot less 'sparking' as the points operated after the coil and condenser swap. Guess these ol machines dont really like a full 12v at the coil.

[Achto 27,505]

28 minutes ago, Greentored said:

Guess these ol machines dont really like a full 12v at the coil.

 

They don't mind the 12v at the coil, in fact when you start the tractor the coil will receive 12v. The issues increase as the battery charges & pushes the voltage above 12v. The ballast resistor increases resistance as the currant increases keeping the coil from over heating and failing. I had a new to me tractor that some one installed a coil without an internal resistor that would run great as long as the voltage regulator/rectifier was un plugged. With the regulator plugged in it would run for a while then sound like it would go under load and shut down. Went nuts trying to figure out what was wrong with the charging system. After I figured out that it had the wrong coil. I replaced it with an internal resistor coil & now it purrs like a kitten.

Edited September 16, 2020 by Achto

[953 nut 55,077]

8 hours ago, Achto said:

The ballast resistor increases resistance as the currant increases keeping the coil from over heating and failing

Almost correct.   If @Save Old Iron were here he would point out that the resistance remains constant but the voltage drop across the resistor will go up as system voltage increases.

[Greentored 3,201]

20 hours ago, Achto said:

 

They don't mind the 12v at the coil, in fact when you start the tractor the coil will receive 12v. The issues increase as the battery charges & pushes the voltage above 12v. The ballast resistor increases resistance as the currant increases keeping the coil from over heating and failing. I had a new to me tractor that some one installed a coil without an internal resistor that would run great as long as the voltage regulator/rectifier was un plugged. With the regulator plugged in it would run for a while then sound like it would go under load and shut down. Went nuts trying to figure out what was wrong with the charging system. After I figured out that it had the wrong coil. I replaced it with an internal resistor coil & now it purrs like a kitten.

 I'm very familiar with the automotive '12v to start, 8-9v running' (anyone who drove an old chrysler knew-  carry an extra ballast resistor in the glove box haha) but had no idea the same applied to tractors, and certainly had no idea it would affect the performance!

So I take it Kohler/Wheel Horse accomplished this with an internal resistor coil, so I can still run a straight 12v to the positive side, correct?

[Achto 27,505]

14 minutes ago, Greentored said:

So I take it Kohler/Wheel Horse accomplished this with an internal resistor coil, so I can still run a straight 12v to the positive side, correct?

 

I think that a lot of companies waited until Delco decided to put the resistor in the coil. Then they rejoiced and switched to that coil. Other companies just couldn't let go of the external resistor coil.

[ebinmaine 67,277]

59 minutes ago, Greentored said:

So I take it Kohler/Wheel Horse accomplished this with an internal resistor coil, so I can still run a straight 12v to the positive side, correct?

With a standard Kohler coil or most any internally resisted 12 volt coil, yes.

 

 

[tunahead72 2,403]

On 9/16/2020 at 7:21 AM, 953 nut said:

VW used coils with a built in resistor beginning in 1967, prior to that all VW electrical systems were 6 volt and had no need for a resistor.

 

On 9/16/2020 at 7:42 AM, 953 nut said:

All of the above will work, VW coils are plentiful so that is what I buy.

 

Do you have a particular VW coil that works well for you?  Maybe a Bosch?

 

[Achto 27,505]

On ‎9‎/‎19‎/‎2020 at 9:02 AM, tunahead72 said:

Do you have a particular VW coil that works well for you?  Maybe a Bosch?

 

Brand name will not matter as long as it is a 12v internal resistor coil. No need to go with a high out put coil either, you will not gain much of anything by it.

[WHX?? 48,780]

While we are on the subject in looking for a chrome coil for Cindy's 702 custom, looking to add some bling under the hood and old coil is pretty battered and dented, I am having trouble finding one that is internally resisted. Finding lots of these tho.

https://www.vintageautogarage.com/Chrome-12-Volt-Ignition-Coil-p/s1208k.htm

if I have to go this route should I be looking for specific ohm values in the coil and resistor? 

Noticed most coils are 3 ohm but vary. Resistors also vary. 

 

Edited September 21, 2020 by WHX24

[Achto 27,505]

There is always this option Jim.

https://www.speedwaymotors.com/Chrome-Coil-Bracket-and-Cover,727.html?sku=91017485&utm_medium=CSEGoogle&utm_source=CSE&utm_campaign=CSEGOOGLE&gclid=EAIaIQobChMI5YjqkMj66wIVxMDACh1pZwjYEAQYASABEgIJhvD_BwE

[WHX?? 48,780]

Yah I spied that too .. trouble is, I think,  the bracket needs to be at the very bottom of the coil for clearance and I bet that one is spot welded on. 

[pfrederi 17,666]

Farm tractors conversions to 12 v use a 2 ohm ballast resister  most auto applications are 1.6 ohms.  Frankly I think either would work..  The 3 ohm one in your link sounds a tad high  but wold probably work ok..  Note these things get HOT!!! and do not do well if they get wet ...like blowing snow....

[Greentored 3,201]

Resurrecting this thread:

It began rattling again during heavy use, shortly after this thread died. I literally throttled up and slowly adjusted the point gap while running til it got quiet, locked her down and put her to work and its been that way since September.

Now that grass season is done, I am diving in to this thing. I verified EVERYTHING again- TDC/20, coil, points, condenser, valve timing, etc...  and checked with a ohm meter to see where its been running at.

2 degrees AFTER TDC! Yes, its a dog compared to the average 12hp, obviously. If I set it at 20 the power is great but rattles like an early 7.3 Ford diesel ha. Even 10-12 ain't much better.

Im starting to wonder if the ol girl doesnt have a loose rod, and taking timing out quiets her down.  Is that a possibility before I strip this thing down and find nothing?

 

[rmaynard 15,427]

Sometimes it is hard to determine by ear where the rattling is coming from, but my guess is that it is coming from the connecting rod. Changing the points gap, thereby changing the timing, will tend to quiet it down, but you will lose power in doing so. I never use the .020 as my final. I only start there and do a static timing adjustment using a meter and viewing the marks on the flywheel. Once you have determined that the timing is right, and noise is still there, you will probably have to do a deep dive into the engine. 

 

But here is another thought. Many of the K-301'S had balancing gears. As they wear, they can be a noise producing problem, many guys have just taken them out. Either way, you will at least have to remove the pan. If you don't want to completely remove the connecting rod, you can always check the journal wear using Plastigage. 

 

Edited December 14, 2020 by rmaynard

[ebinmaine 67,277]

1 hour ago, Greentored said:

starting to wonder if the ol girl doesnt have a loose rod, and taking timing out quiets her down.  Is that a possibility before I strip this thing down and find nothing

 

1 hour ago, rmaynard said:

Changing the points gap, thereby changing the timing, will tend to quiet it down.....

 

 

I would agree that it could be a loose connecting rod.

Have we verified that the flywheel key is tight?

[Greentored 3,201]

@ebinmaine oh yeah. Right before I snapped the threaded snout off the crank when removing the flywheel 

I think @rmaynard is right, might be diving into her and checking some clearances.

[ebinmaine 67,277]

I figured you'd checked that. 

 

Keep us posted!!

[Mickwhitt 4,589]

Several threads at the moment touching on the same problems.

I made a new throttle butterfly shaft for mine as it rattled like a tin **** house in a thunderstorm.

Certainly ruled out running too lean due to air ingress.

Condensor is something I'm.looking into and I timed mine with a strobe and it is a little better than static timing.

Watching with interest 

Mick 

 

[Handy Don 12,152]

6 hours ago, Mickwhitt said:

like a tin **** house in a thunderstorm

Great turn of phrase, Mick. Happens that I've been enthroned in a tin-roofed *** house during a thunderstorm and can vouch for the noise level!