How to Hone a Cylinder on a Motorcycle Engine

If your pistons and cylinders are within serviceable limits according to your motorcycle manufacturer’s shop manual, you can install new piston rings and re-hone the cylinders.

If your cylinders are out-of-round and beyond serviceable limits, they may need to be bored to the next size up.

Cylinders that need boring should be taken to a machine shop with the right equipment.

Can you hone a cylinder yourself?

Honing a cylinder with a ball hone is a fairly simple job.

It only takes a few seconds to finish a single cylinder, and with the proper prep and practice, should go pretty well.

If you’ve got a history of over-torqueing bolts or have shaky hands, maybe it’s best to leave the job to a professional.

How to Hone a Cylinder

To hone a cylinder, you’ll need to:

1. Insert your hone tool into a proper drill.
2. Use a generous amount of hone oil/lubricant in the cylinders and on the hone tool.
3. Put the drill on a low speed and steadily move down the cylinder.
4. For ball hones or flex hones, you should start the drill before the tool enters the cylinders.
5. Move the hone tool up and down the cylinder bore, and make sure to keep the tool straight and centered.
6. Always keep the drill moving when it is in the cylinder, wait until it is out to stop it.
7. Continue for up to 1 minute, making sure to keep the drill moving and cycling the flex hone between halfway out the top and bottom of the cylinder.

Your goal is to create a 45 degree crosshatch pattern in the cylinder wall and to break up the glaze.

You do not want to take off any cylinder wall material if everything is within spec.

The process should not take very long – typically no more than a minute.

When you’re finished, clean and dry everything thoroughly before reassembly.

Run a rag through each cylinder to ensure there is not dirt or particles in there. Continue to clean the cylinders again until your rag comes out clean.

Apply some fresh motor oil to the freshly honed cylinder walls before you put it all back together.

1. Get the Right Tools to Hone a Cylinder

The first step to honing your motorcycle’s cylinders is to gather the rights tools.

You’ll need:

• A honing tool.
• A drill.
• Honing oil.

The easiest flex hone to use is generally going to be a ball hone.

Choose the a ball hone in a size that matches the diameter of your cylinder.

Most manufacturers will have a recommended range.

As the hone spins, it will expand as needed to create the desired cross-hatch pattern on the cylinder walls.

Choosing a honing tool that is too large will take off too much material from the cylinder walls.

Next, you’ll need a power drill that can get up to about 1,200 to 1,600 RPM.

Make sure the battery is charged and the speed is set correctly.

Insert the ball hone and secure it properly so that it spins straight and true in the drill.

Finally, you’ll need to lube the cylinder walls with honing oil.

In a pinch, most types of penetrating oils will work, but a specific honing oil or machinist’s oil will be your best bet.

2. Prep the Cylinder

To prep the cylinders for honing, you’ll first need to apply the honing oil.

First, complete the disassembly and clean up the cylinders.

Place the cylinder block over a drain pan and apply some oil.

You’ll want to secure the engine block so that you can move the hone up and down the cylinder completely without running the risk of the block moving or falling over.

3. Hone the Cylinder

Apply some more honing oil to the honing tool and continue to apply honing oil as you hone each cylinder.

Pull the trigger on the power drill and get it up to full speed.

Insert the hone into the cylinder while applying more oil.

Keep the drill straight, and keep it moving at a constant speed.

You’ll want to move it up and down the cylinder a few times (typically no more than 5 or 6).

Each cylinder should really take no more than 15 seconds.

Remember, the goal is to create a crosshatch pattern on the cylinder walls. You are not trying to remove much material.

Less is more when honing a cylinder yourself.

4. Clean the Cylinders

After you’ve finished the process for each cylinder, you need to clean up.

Start by using a clean rag to wipe down the cylinder walls and remove any metal shavings.

Wash the engine block with soapy water.

Once rinsed and cleared of debris, dry the engine block completely with a clean rag and compressed air.

Apply a layer of oil to the cylinder walls after drying it to prevent any flash corrosion.

What does Honing a Cylinder do?

Honing a cylinder takes a small amount of surface material to help seat new rings.

Giving your cylinders a light hone will help break the glaze that’s built up on the cylinder walls to help the new rings seat.

If you’re working on a neglected project motorcycle, honing the cylinders can help remove any rust that has built up as well.

This will help improve engine performance and possibly eliminate any smoking.

There a several types of cylinder honing tools to chose from – ball hones/dingleberry hones and blade hone/stone hone tools. Hone tools will come in different grits, be sure to read the manufacturer’s instructions and recommendations before selecting the hone for your job.

Be sure you purchase (or set) the hone tool at the correct size for your cylinder.

How Long Should You Hone a Cylinder?

The type of cylinder hone described on this page is a quick process.

Each cylinder should take no more than 15 seconds when done properly.

The goal is really just to create that crosshatch patter to help the new rings seat themselves when everything is reassembled.

If you hone for too long or with too much speed, you run the risk of increasing the bore of the cylinder – thus reducing compression and causing leaks when you reassemble the engine.