Matching carburetors for Kohler engine

[mtarsus]

Hello,
Old yellow lawn mower with Kohler mv16 (14hp). Needs carburetor. OEM carb costs $270, not worth it. Do any of you know if it's possible to use a carb from another make/model engine with decent results? I don't mind if it needs adjustment or fiddling to get good mixture, etc etc. I just want to know if there are other carbs that will fit onto this engine without some kind of adapter...


Thanks

 

[mhomrighausen]

Okay. Mark T. One can assume that your Cub Cadet is the 1430 noted in your profile. What exactly is wrong with the current carburetor that it can't be rebuilt with a kit? Perhaps you should be posting pictures and showing the carburetor's current condition. Is the throttle shaft area worn or ???? Also if the tractor isn't worth putting $270.00 into a new carburetor then perhaps the whole tractor is worn out. Not to sound mean or anything as such however what you are asking is like me asking .... "My 125 engine has over 700 hours on it and I'm pretty sure it needs a new head gasket. Should I rebuilt the whole engine?"

Summing up.... MORE INFO PLEASE. I.E. pictures, etc.

 

[mtarsus]

Hello Mr. H,

The engine does not have a carburetor. I took it off last year and left it in a coffee can. After spring cleaning this year, I can't find the original carb to save my life. The engine runs, it ran before I took the carb/air cleaner off of it.

The engine would start just fine, run for 5 minutes, then backfire 10-15 times and sputter to a halt. At the time I wasn't sure what to do with it, I was told that the old carbs don't like ethanol gas, so I assumed something was wrong with that and took it apart for cleaning/troubleshooting.

I wound up getting sidetracked with a couple of big projects on my house, and the mower sat in pieces. Fast forward to present day, I've decided to noodle with it for laughs, but can't invest more than a few bucks into it. I am fairly certain that the carb is long gone, it was probably thrown out while I was gutting the living room/kitchen.

If I can find another, cheaper carb that fits the engine, then I can at least try to get it running again. Maybe discover the old issue and eliminate it.

So, as my first question asked, are there other makes/models that have a carb which will fit this engine? Is there a website which sells carbs or special fittings for the carbs? Or is there a way to tell if a manufacturer has a flange which will fit onto the existing hardware for the engine? The only thing I need to find is this piece of information and I should be able to continue figuring it out. I just can't see the point investing so much money for a new carburetor for a mower which has seen better days; I'm just fixing it for fun.

 

[mhomrighausen]

Mark T. You might want to check with one of our Sponsors above.... R.F. Houtz & Sons. They part out Cub Cadets and may have what you are looking for. Just click onto their Business Card and their website will come up.

 

[mtarsus]

Hello again,

I have purchased another Kohler Mag with identical carb and other parts (this one is 19.5hp, seems to be slightly larger displacement, also uses different plugs). I intend to either swap this engine entirely onto my 1430, or at least transfer the carb....

However, I started to dismantle my original Kohler and found a couple of odd things. Firstly, the cylinder head for #1 has tons of caked grime and oil. The empty space under the engine shroud was filled with a crumbly black material that appears to be grass/yard debris mixed with engine oil. All of the cooling fins formthe head were filled with this black gunk as well. Could this be a sign of a leaking gasket? There is no way this is good for the engine, it was trapping tons of heat.

Secondly, the exhaust port for #2 is leaking gasoline. Unburnt gas is literally dripping out of the exhaust port. What does this mean?

Thanks guys

 

[nbextermueller]

Yes, it has an oil leak from somewhere.

You said your original Kohler. Would that be the one without the carb? How is it getting gas to leak without a carb on it. I'm confused.

 

[mtarsus]

I am not sure, but the exhaust port for the no-carb engine had fluid inside of it when I removed the muffler. From what I remember, last week, it was oily and smelled like gas.

After discovering the leak on the head gasket, I have decided to swap the new 19hp motor onto it completely, get the mower running, and then fix up the original 16hp Magnum on the side. Gaskets should be cheap enough. Worst case, I can rig something using a tube of gasket maker from a Pep Boys or something, anything to make it work well enough.

I was told that the new motor ran on starting fluid, but needs a fuel pump. At the time of purchase, I was on the clock and it was 90 degrees outside, so I was not about to dismantle/finagle it to find out if the seller was telling the truth. Either way, I will certainly find out.

I found that the fuel pump on my own Kohler is actually blown. One of the spring assemblies disintegrated when I took the cover plate off to inspect it. I am not sure if this was a cause for one of my issues, or if it had been held in place by the housing well enough to continue working, and perhaps my disturbance caused it to completely break. No big deal, new pump came in the mail a few days ago. Eager to slap everything together and see it run.

I am a little concerned about this new engine, though, because the plugs are pretty dark and have some material on them, looks to be lots of oil. I get the impression it has a lot of hours on it and may not be the healthiest motor out there.... I was told that it came off of a Craftsman GT6000. From what I've read, those mowers were made in the early 90's, somewhere in that time period, so there's an excellent chance that this motor has well over 500 hours on it. If I wanted to give it a little boost, do you think a can of Restore could help improve the compression? Or is that something just for cars? If so, why?

And finally, how difficult is it to replace piston rings on a motor like this? If I decided to do something like that, I would have to dissemble it down to the crank so that I can replace the rings and reinstall everything. Maybe a 1-day job?

 

[jchamberlin]

Mark, if your rings aren't sealing the chances are that there is too much clearance between ring and cylinder wall. Replacing the rings is seldom a long-term solution, as I understand it. The cylinder walls are often worn so that they are no longer perfectly round, but ovaled and no longer straight, but tapered (usually larger at the bottom end). By the time everything is honed out and trued up, you often find yourself at the size where a new piston is called for.

Oil can also get to the spark plugs through the valves, the valve guides specifically. Again, the wear makes them oval and taper. Before any of this happens, though, the head gasket is usually found to be leaking.

Then there is the matter of metal fatigue in the connecting rod, as well as the large end elongating and ovaling which creates lubrication problems. If not treated the rod will likely seize on the crank, or worse, break and chunks exit the block leaving a window behind.

By the time you add it all up, and figure your time, the price of a NEW replacement engine doesn't look all that bad anymore.

Good luck sorting out the problems on your 1430 lawnmower.

 

[mtarsus]

Thanks for the info, Mr. Chamberlain. I suppose I'll just get it running and leave it at that. Fun project.
This evening, I removed the old Kohler and installed the new one. At this time, I have it setup enough to run the engine but not to power anything on the tractor

Unfortunately, I have been unable to start it. It cranks very slowly, not nearly fast enough to start the engine. In my attempts to troubleshoot, I have taken the following steps:
1. New battery
2. Replaced starter
3. Cleaned/checked all ground wires
4. Removed and cleaned solenoid terminals/grounding contact

I am not sure what to do next... It seems that the engine itself is reluctant to turn, because it had the same problem with 2 separate starters...

Any ideas, gentlemen?

 

[mtarsus]

I have meditated on this issue for a few hours. I am going to try/test a few things:

1) test voltage at the starter to ensure 12v.
2) apply electricity directly to the starter to weed out electrical gremlins
3) try starting/jumping from a running automobile - the logic behind this is assuming the battery just doesn't have enough cranking amps (it's a 280). Also, the battery charger/jumper that I use does not create sufficient current to really jump an engine in the strictest sense. It is more of a fast charge using low power.

 

[mtarsus]

Correction: Jump from a car battery while the car is NOT running. Apparently doing it with the car running is a great way to create an explosion.

If all else fails, I plan to pop-start it using the shaft pulley and belt from another mower.

 

[mtarsus]

Sorry for posting so many times in a row. I normally don't do that, but the software won't allow me to simply edit posts after 30 minutes.

I determined the cause of the starter issue. It was poor power delivery, due to the method I'd chosen to attach the battery (beside the tractor, using Romex cable for length). I installed the battery properly and the engine turns perfectly well.

Now for the next issue: no fuel delivery. I have confirmed that the float bowl is full of gas, so everything up to the carb is working. The plugs are dry, though. My first notion is to look for a clogged jet, but I am not sure how to clean it since the carburetor uses a fixed jet that doesn't seem able for me to remove, at least not without a special tool or some knowledge I have yet to learn.

I also had the carb apart last week and I cleaned everything as well as I could, given the limitations with the fixed jet.

What are the stock settings for the mixture screws? I have mine at ~2 turns each; I figure rich is better than lean.

Should I check the valves? How would I do that?

 

[mtarsus]

Using a multimeter, I have determined that the ignition coil is working, sending juice to each plug. As I continue to crank and crank the engine, I am not smelling anything. No unburnt gas. I have set the carburetor to maximum throttle with the choke on all the way. Occasionally, I will see puffs of smoke coming from the exhaust pipes, but it does not seem substantial enough for me to believe it is actually smoke, perhaps only dusty material from the pipe.
It appears to me that there is simply no fuel mixture entering the cylinder. I have visually inspected the intake valves and they both are functioning, although I've no clue if the timing is true. I also confirmed that the engine is drawing air by placing my palm over the carb intake.

I removed the carburetor a second time, and thoroughly sprayed carb cleaner into the fixed jet. The fluid made it past the jet and trickled from the opening of the carb. I noticed that the needle for the jet seems to have a tiny hole in it; is fuel supposed to go through this hole? I was under the impression that fuel was to pass between the needle and the gap in the jet, thus creating a mist which is drawn into the engine.

At this time, I have decided to do a rudimentary compression test, perhaps something I should have done earlier, though I do not own one and hoped to avoid buying it. I will also purchase a plug tester to verify the plugs are actually firing.

I am very confused by this dilemma. On the surface, it appears that everything is functioning properly. Perhaps the engine just needs a shot of ether to "break the ice?" I will purchase some of that, too.


Sigh. It will be another long night.

 

[nbextermueller]

I don't have much to add to help you out. But I wanted to touch on comment about your engine having 500+ hours on it.

That's really quite low. The Mag 20 in my 2072 just hit 1208hrs and my KT 17series 1 in the 782, the hour meter stopped working at 1512hrs. Both on the OEM build. They've never been open.

So if its worn that badly, it's a sign of abuse not age.

I'm surprised you didn't melt that Romex using it as a jumper cable. It's designed for 20amps, NOT 280!

See if will run on starting fluid or pour gas in the carb. That will tell you if it's a fuel issue or not.

 

[mtarsus]

Could I be creating a hyper-lean mix by cranking without the air cleaner? Right now it's just the throttle body, aka the 90° elbow, or whatever. Maybe that's keeping the choke from making it rich enough to start?

Also, this engine had caked grime in the same place as my original engine. Not nearly as bad, but it was there nonetheless...

 

[mtarsus]

OK, as you suggested, I tried it with ether and it fires right up. However, it dies immediately because it's just not getting any gas. There is obviously something wrong with the carb. I'll have to take it apart again and ponder over it for a good long while...

Like I said, there's gas in the bowl. I am not sure why it is not aerating the fuel. Perhaps I will study diagrams online to be certain there is not some essential piece of the carb that I installed wrong or somehow lost.

 

[nbextermueller]

The carbs are pretty simple. Gas fills the bowl, the float rises, and the needle attached to the float closes against the seat when the float, well... Floats.

The vacuum the engines produces as the piston goes down sucks gas from the bowl, up through the middle of the carb and past the main jet. Then gas comes out the Venturi area.

I would pull the back off, take the bowl, float, needle, and any mixture screws completely out. Then use carb cleaner or brake parts cleaner WITH the straw on the can, press the straw on every little hole you can find and make sure cleaner comes out somewhere other than where you are spraying. Tip: spray gently at first.

I suspect, just like you, gas is not getting past the main jet. Spray like crazy until it comes out the other side. I you need to poke, use a long plastic bristle from a dish brush or something. 30-50lb fishing line, or very thin craft wire works good too.

You'll get it loose. Just keep working at it until all the ports are clear. And typically main jets are around 1 3/4 turns out and the air screw is about 1 to 1 1/8 out as a start.

 

[mtarsus]

I finally got it to run. My guess is that I wasn't letting the bowl fill enough for the jet to start spraying. What I did differently was continually shoot it with ether until it took over on its own, instead of giving it one spritz and hoping for the best. It is definitely hard starting, I think it's just a tired engine, but I'm not worried; <$200 for a complete working engine is good no matter how poorly it runs. It will also be easier for me to adjust the choke/throttle once the cables are hooked up, so it might not be so bad.

I tried to upload a video but the website was not behaving; I waited ten minutes and gave up.

The cylinder next to the dipstick (is that #2?) Seems to have a misfire. It makes that distinct puffing/low popping noise and gives a little puff of white smoke every 2 or 3 seconds. I am assuming that is probably every 5th or 6th detonation, although I've no real clue. Anyway, is that a valve issue? Can I do something to tweak the timing without tearing it all apart? I've read that Kohler Magnums are usually maintenance free when it comes to valve timing. The smoke also seems to be coming from somewhere other than the muffler. I do not believe it is a head gasket because the outside of the cylinder is very clean, no shmutz or oil of any kind.

I am going to hook up the drive pulley and get this thing moving. Very excited!

 

[mtarsus]

I have installed the pullies and the PTO clutch. The mower runs and drives perfectly well, it has no issues. Also, it starts right up on its own, no ether, the choke/throttle just need a little finagling.

Something is definitely off with cylinder #2, though. At least at idle. It seems fine at High RPMs. It also has some blowby, enough to send little droplets of oil flying from the filler tube. Not enough to actually see the air/smoke, though, so it can't be terrible, maybe a 7/10 compared to an excellent engine. I've seen cars with such blowby that there is actually smoke coming from the oil fill, thankfully they were not my cars...

Does anyone have a photo/diagram of how the choke/throttle cables are supposed to go?

Also, it won't shut off when I kill the ignition, I have to use the choke. I am assuming it has something to do with the relay that connects to the stator and ignition coil, because I haven't set them up yet... Am I right or is there something else?

 

[mtarsus]

I accidentally left it sitting outside for an hour with the ignition on, now it won't do anything. I had to jump it with a direct line from the starter. Did I fry the solenoid by accident? I do not have the means to test it right now because I destroyed my multimeter yesterday when I tested the spark plugs for energy (I grounded the multimeter in series and sent the juice straight through it, it hasn't given any readings since. $7 @ HF, life goes on).