Runaway engine-Governor Issue?

[Bentoolong 94]

Good News!!!

 

I got my C-120 running today and not "on the bottle". I cobbled together a battery to the solenoid and coil and gave it a shot of carb cleaner and it popped and threw some junk off the motor.

 

I opened the valve on the tank and after cranking, it fired up. Ran fairly well but it was hard to control the RPM's and it was backfiring a little (I don't have the muffler on currently so there's that). I had it idling fairly well at one point but then had issues getting it started. I pulled the brand new plug and it looked wet and black like it was running to rich.

 

At that point, I noticed I had gas leaking from the fuel line at a few points so I shut it down. After looking a little closer it seems the hoses are a little crusty and showing some cracks. I then decided to take a look in the fuel bowl. I found the mess below. At that point I figure I'll need to get a carb kit and go through it and replaces hoses and filter as well.

I think I have a Kohler 4705313 carb on this machine. Is there a superseded number for that so I can find an overhaul kit? The carb does not seem to have worn shafts and I like to rebuild rather than replace if I can.

 

So I have found out this much. The engine sounds rather good. No clunks or smoke. The starter and solenoid are good. I think I'll invest a little in the motor and see if I can get it purring and then check out the tranny.

 

In the process of doin this work today, I pulled the choke cable housing loose from the mechanism on the dash. I'll need to remove the dash and try a repair to that and lube the cable while I'm at it.

 

Having fun now!

 

Bentoolong

 

Edited August 31, 2021 by Bentoolong

[roadapples 6,983]

Unless everything has to look original, I highly recommend the blue/purple clear fuel line. It's supposed to be good for 100% ethanol. And even if you use ethanol free gas you can see the fuel flow.  A to Z and many others sell it. I got a 25ft roll to put on all my tractors...

[peter lena 8,627]

@Bentoolong looks like dirty fuel tank debris , I  would pull that first, flush out , put in a new tank valve , and clear vinyl fuel line , have 2 filters on my horses , one near the tank and another near the carb , also put STA-BIL in every drop of my gas , no debris of any kind , instant starts and zero fuel issues,  pete  

[peter lena 8,627]

@roadapples , when you replace that fuel tank valve , use this  SUPER LUBE  .https://www.harborfreight.com/85-gram-super-lube-grease-cartridge-93744.html?utm_source=google&utm_medium=cpc&utm_campaign=12144811130&campaignid=12144811130&utm_content=117789309758&adsetid=117789309758&product=93744&store=3182&gclid=CjwKCAjw092IBhAwEiwAxR1lRia5SIQ1sObBpwW3TtzfSKlx5EA11KiqS6ybos0ik7oHe5IE12biBxoCKIoQAvD_BwE , which is also a dielectric grease . made to work with rubber grommets , makes the new tank valve installation smooth and easy , used it as a millwright for years , on food grade products , on  maintenance. also reroute your fuel line to eliminate tight areas . did this on my 3 horses , no more fuel issues , clean carb bowels  . pete 

[Bill D 1,921]

Replace the float bowl with a steel float bowl.  Briggs P/N 221995.  Looks nice and cheaper than a Kohler bowl.

[peter lena 8,627]

@Bill D thanks for that , simple as it is , correcting a nagging issue is the way to go , make it as bombproof as you can , (   only my own opinion  ) pete

[Jeff-C175 7,202]

21 hours ago, peter lena said:

put in a new tank valve

 

@Bentoolong

 

And to be clear, a NEW TANK GROMMET!  VERY important.  I came out to the shop last fall to the smell of gasoline.  BIG puddle of fuel on the floor.  Thank the higher powers that there was no ignition source!

 

REPLACE THAT GROMMET!

 

Edited August 15, 2021 by Jeff-C175

[Bentoolong 94]

No need for a grommet. The PO did that much for me and he also replaced the valve. No leaks that I can see form that area.

[Bentoolong 94]

Since I've got the carb off, I'm considering going in and checking valve lash. After working on this tractor for a while, I don't trust anything.

 

Is this something that gets done occasionally? Maybe clean the breather setup?

 

BTL

[tunahead72 2,412]

YES to both questions, especially as long as you have the carb off already.

 

[Bentoolong 94]

Do the gaskets come off nicely or should I get a set ordered? RTV?

 

Thanks "Tuna"

 

Bentoolong

[tunahead72 2,412]

They'll probably be damaged when you remove them, I would count on buying new ones.  But I'd also recommend taking the whole assembly apart before you order parts, you may also have to replace the filter, seal, reed, ....  And check the service manual to see what order all the various parts should be installed, to make sure your engine is actually breathing, not choking.

 

If your covers are nice and flat, and the other pieces are in good condition, you shouldn't need RTV or any other sealant.  I've used Permatex #2 in the past, but lately I've just been reassembling dry, seems fine so far.

 

There's some good threads here on the forum that address some of the details if you need more information.  This is one of my favorites for some reason :

Kohler K241 Crankcase Breather - Engines - RedSquare Wheel Horse Forum

 

[Jeff-C175 7,202]

4 minutes ago, tunahead72 said:

taking the whole assembly apart

 

And take pictures, lots of them, as you disassemble!  Especially if it's your first time doing it!  You'll be glad you did when you start putting it back together.

[Bentoolong 94]

I had some issues with the carb kit and I just ordered some valve cover gaskets. Things are moving slowly.

I may have more to report by next weekend.

 

So I'm moving to checking other things. 

After spending a little time with this machine I am leaving nothing unchecked due to what I have found so far.

 

I've done some research on the engine but can't find anything helpful regarding seeing up the governor/ throttle linkage.

 

I haven't checked anything yet. How is the adjustable rod at the top of the governor arm (to the carb) adjusted? That seems like it might be a "set it once" item. Messing with the spring tension may be fine tuning based on how the engine performs or how it is used.

 

Any suggestions?

 

Bentoolong

 

 

[pfrederi 17,739]

Abut 3 inches from end to end.

 

Manual shows factory spring settings.  Not normally an item that needs changing but after you get it running if it doesn't respond well you may want to adjust.

[Bentoolong 94]

Thanks Pferdi,

 

I don't see that measurement in my manuals. Could you provide a link to what you have or is that a measurement based on your experience?

Bentoolong

[pfrederi 17,739]

20 minutes ago, Bentoolong said:

Thanks Pferdi,

 

I don't see that measurement in my manuals. Could you provide a link to what you have or is that a measurement based on your experience?

Bentoolong

I measured a couple on working tractors

[tunahead72 2,412]

Paul's right on with that measurement.  There's also an early version of the Kohler K-series service manual that has a diagram showing the same thing, it's on the last page of section 5 here:

Engine Kohler K 91 K141 K161 K181 K241 K301 K321 SM 1972.pdf - Kohler - RedSquare Wheel Horse Forum

 

Time to check mine. 

 

[Bentoolong 94]

I'm glad I checked the valve lash. The exhaust was spot on but I couldn't get a .002 feeler gauge into the gap on the intake. I got it set better now. Hope I don't have a burned intake valve from not closing all the way.

 

Someone else has been in there because it looks like some RTV was used last time they checked the valves.

 

I've got some gaskets coming soon and when I get the valve breather assembly back together, I'll bolt on the carb, run some new fuel line and see if I can get it running. Maybe Saturday.

[Bentoolong 94]

I ran into a little snag. I got my crankcase breather gaskets in the mail today and that was the item that was holding up progress in getting the engine running.

 

I got the valve lash set and everything it cleaned and ready to assemble. I had the breather "filter" soaking in some mineral spirits to get it clean.

I got it dry and while handling it, small pieces just started to flake off. I'm not interested in having small pieces of anything getting in the reed valve so it looks like I need to get a new one.

 

I don't think it filters anything. It more than likely just causes flying oil spray to turn into a liquid so it can drain back into the crankcase rather than blow out the breather.

 

The part # is KOHLER 47-050-01

 

Do I need to spend the $10 plus for this little part or is there something else I could use? Something would need to be able to stand up to heat and hot oil. 

I'm bummed that this is going to hold up progress but I want to do the right thing.

 

Thanks

Bentoolong

[Bentoolong 94]

Good news/bad news.

After cleaning the carb and doing some adjustments the engine is running smooth. Burns a little oil but not to bad.

 

My issue is with the governor. I'm still trying to figure out how to set the throttle cable and the governor. I think all the springs are in the correct holes. I have not changed those positions.

 

I can get it to idle but when I turn up the throttle it speeds up rapidly and then I can't get the RPM's to come down with the throttle lever. I need to grab the throttle shaft at the carb and force it down to idle. It runs way to fast at full throttle.

 

I have not tested the position of the governor arm on the shaft. What type of "feel" should I get from the governor shaft. Should there be free movement. Should I feel a springiness at the end of the travel. What else should I be looking at?

 

Do I have a broken internal governor? If that is the case, I'm calling "uncle" on this machine.

 

Thanks

Bentoolong

[pfrederi 17,739]

Looking at one of your carb pics it looks like your high speed stop is too far over.  Also is your throttle cable interfering with the governor linkage?

 

 

[Bentoolong 94]

Thanks,

 

"High Speed Stop" that's a new one on me. What should that look like at idle or full speed? Is that used to set the high RPM?

Just including some pics to show my setup. Seems like there are a lot of variables in this area.

 

How to make the initial throttle cable length adjustment for starters.

 

That small lever thing moves less than 1/8" over the travel of the throttle cable with the engine off.

I made sure that nothing interferes with the movement of any of these parts.

 

BenToolong

 

[pfrederi 17,739]

Move your control rod tot the top hole of the bell crank.  High speed stop is at yellow arrow.  It is way to far over move it up past the blue line I drew. Then check your RPM.  If it is too fast go more counter clockwise.    it is a fairly sensitive adjustment.  A small movement makes a biig change in RPM. 

 

 

[Bentoolong 94]

I will do that. 

 

There are two Bell cranks involved here if my understanding is correct. The one on the governor shaft and the one the throttle cable attaches to.

I think you mean to move the rod to the top hole on the bell crank that the throttle cable attaches to. Correct?

 

Like I've said before, I don't trust any adjustment or assembly on this tractor. It has been fighting me at every step.

 

For that reason I am going to check the position of the governor crank on the governor shaft. I may need to wait until tomorrow to test all of this.

 

I'm still interested in hearing about how to install the throttle cable where it ends. Do you put the throttle lever on lowest setting and close carb throttle plate and remove all slop in the springs/rods on the governor/throttle mechanism?

 

Ben