The Kohler Command line is a solid, dependable line for smaller vehicles like lawnmowers and golf carts. They come in both commercial and consumer makes, five different fuel types, ad several levels of emission compliance. Each of these models can be rebuilt at home with the proper instructions, practice, and time.
To rebuild a Kohler Command engine, you’ll need to assess your engine’s degree of wear, tear it down following the manufacturer’s guide, then clean and reassemble or replace each piece in turn.
Kohler is a particularly easy brand to rebuild if you’ve got a bit of technical know-how under your belt already. Most of their service manuals are available online for free, and their kits are reasonably priced compared to the engines themselves.
Identifying Your Kohler Command Model and The Parts You Need for a Repair
Kohler has many different models of engines that all have specific needs based on their type, fuel, and accessories. Their website has guides for all products in free-to-download PDFs. Take full advantage of this and match your engine’s model with the accompanying guides.
When you have the guides, you’ll need to identify which repair kits, if any, you’ll need to get to work. This may have to wait until you’ve torn the engine down, but it’s good to look ahead and estimate a cost. Depending on your model, a rebuild kit from Kohler is going to cost you roughly $300, so be sure to set yourself a budget that accommodates this.
You can narrow down your needs by selecting either diesel or gasoline as your fuel and either commercial or consumer models. You can also use their part lookup banks if you have the serial numbers for the pieces you’re working on to find and order replacements as you work through certified dealers.
How to Tear Down Your Kohler Command Engine
According to Kohler’s engine guide, you’re going to need to do several checks before you can start rebuilding.
- Check for sludge. Sludge forms as a by-product of combustion. It’s normal to have a small amount of it present, but if there’s significant accumulation, to the point that it’s interfering with function, it might be a warning sign that the oil hasn’t been changed often enough, your engine’s ignition timing is off, or the carburetor is over rich.
- Check your cylinder walls. If there’s a lot of unburned fuel, there might be some scoring along the cylinder walls where lubricating oil has been washed away.
- Check your pistons. If you’ve got issues with combustion, in more extreme cases, you might have more severe problems with the pistons. This can include a burned-out top ring or worn grooves.
- Check for oil leaks. Finding where the leak is coming from can show you other signs of wear on seals or problems with your breather systems’ servicing.
After you’ve done your checks and identified any issues, you’ll want to clean everything down. Normal soap and warm water work fine for this, although there are commercial cleaners available. Cleaning down your parts will make identifying further problems much easier, as well as making reassembly easier.
Watch this YouTube video on the disassembly process:
Always work in a properly ventilated space when you’re cleaning. Some cleaners can give off dangerous fumes, either toxic or combustible, and you don’t want to breathe that in. Start with your cylinder heads and blocks, then move on to your pistons, then valves, connecting rods, camshaft, crankshaft, oil pump, and governor.
How to Rebuild Your Kohler Command Engine
The rebuilding process is fairly simple and straightforward if taken one step at a time. Make sure you’re following the right order, which will essentially be the same order that you broke everything down in. Realistically, you might be rebuilding at the same time as you’re breaking down.
Working with Cylinders
Start with the cylinder heads. Check to see if there are any hot spots or blown gaskets. If it is in good condition, scrape the carbon deposits out using a wooden or plastic scraper, being careful not to nick or damage the gasket, then replace the heads. If it needs to be replaced, set the new heads and gaskets in here.
Move on to the cylinder block and barrels. You’ll do nearly the same thing here, checking for wear and adjusting as you go using a boring bar to resize and honing as necessary. You’ll want to check the bore clearance before reinstalling the piston, a step that’s often overlooked but is vitally important to avoid failure in the future.
Working with Valves
Up next are the valves. If your machine is hard starting or if there has been any power loss with overconsumption of fuel, you’ll want to pay special attention here, as these can be signs of fault. Remove and clean the valve with a wire brush. Check for warping, corrosion, and other defects.
If it’s still in good condition, it can be reused, but anything more than a 1/32 margin should be replaced. To check the guide, you’ll need to measure the diameter of the stem at several points, the use the largest diameter to calculate clearance according to a table such as the one shown in Kohler’s online guide.
Check the valve seat inserts for any pitting, cracking, or distorting. Replace them as needed and make sure any new inserts are properly seated. Before moving on. Check for and replace broken springs.
Working with Pistons and Rings
Now you’ll need to inspect the pistons and rings. These usually won’t take much wear on the pistons themselves unless there’s been excessive heat due to lubrication or clearance issues. You can generally reuse the original pins with new rings unless that sort of damage has been done.
The rings will probably need to be replaced more often. They can wear down due to an excess of oil consumption or a low crankcase vacuum, such as when the gap is wrong, causing oil to leak into the combustion chamber. Check the gap before installing new rings according to the instructions included with the set. Always follow the instructions exactly to ensure proper placement.
Making Miscellaneous Adjustments
Check your connecting rods for scoring and replace it if it’s excessively worn down. Move on to the camshaft and crankshaft, checking for missing or chipped teeth and replacing them as necessary. You’ll want to check the crankshaft bearings as well, but those shouldn’t need replacing unless they’re particularly damaged.
Inspect the oil pump and governor for badly worn teeth, including cracks or chips, and replace any troublesome gears. Make sure that everything is balanced properly according to the engine model, and that the stub shaft isn’t damaged or worn out, replacing it if it is.
Repairing Kohler Command at Home VS Professional Repair
There are other issues to consider, such as timing, faults with the fuel pump, or issues with the carburetor’s settings, but those require slightly more advanced repair skills. If you ever doubt that you are going to be capable of doing any specific job, take your engine to a professional to have it serviced. The cost of repair is almost always less than the cost of replacement.
That being said, the only way to learn this kind of mechanical skill is through practice. Make sure that you are comfortable and familiar with your specific model’s repair manual, and be sure to have it on hand as you’re working. If you’re methodical and confident in your work, you should be able to easily repair your own engine in no time at all.