How To Rebuild The Top End On A KTM RFS Motor (Part 1) Video

If you cannot see the videos you may need to upgrade Adobe Flash Player. Upgrade Upgrade Flash Player

How To Rebuild The Top End On A KTM RFS Motor (Part 1)

If you need to rebuild the top end on a KTM RFS motor, but you are not sure what to do, you are at the right place. Our detailed instructional video will walk you through how to rebuild the top end on a KTM RFS motor. Watch our industry expert as he rebuilds the top end on a KTM RFS motor. Trust us to have the answers and instructions you are looking for.


Hi. I'm Eric from, and today I'm going to show you how to rebuild the top end on a KTM RFS motor.

On a procedure like this, it's going to be imperative that you have a service manual. We're also going to need just some common hand tools and specifically you're going to need the Motion Pro chain riveting tool.

To start off with, we're going to use the Tusk spring puller. We're going to remove the header springs, the silencer junction springs, the mounting bolts. There's one on the frame as well. Slide the silencer out of the way. And then on this model, KTM, you need to remove the shock to get the header off. Go ahead and slide that off. Get the header out of the way. And then we're going to move on to the radiators.

We've already drained the oil and the coolant. There might be a little bit of residual coolant that drains out, so be ready to capture it. The radiator mounting bolts, move those out of the way and get the rest of the hoses off. Set those aside.

Now we'll move on to the carburetor. We'll start with the cables. Pull the cover off, loosen the adjusters so you can get some play in there, and take the cables off the cam. There's also the oil breather. We'll remove the air box clamp, electrical connections and move the carburetor out of the way.

Next is the water pump cover. Pull that off. And we're going to go to the oil line that supplies oil to the top end. Now, when you take these banjo bolts out, there's normally a copper washer on top and then a copper washer between the line and the case so be really careful when you pull them off. Make sure you get all the washers.

Alright. Go ahead and pull the spark plug cap, the spark plug out, then we're moving on to our head cover. It's a good idea to keep track of where these bolts go because a lot of them are different lengths.

Then we're going to get our decompression cable, undo that. Our tappet covers need to be removed so that the cover will clear the frame when we pull it off. Carefully slide it out of the way. You might need to maneuver it a bit. Go ahead and finish taking the decompression cable off.

Then we're going to move down to the cam chain tensioner. We're just going to loosen the main tensioner bolt. Then we pull off the mounting bolts and take it out.

Now we need to take the ignition cover off, so the shifter needs to come off. Fold the wires up, disconnect them. Now we're going to go ahead and pull the cover off.

On KTMs, you need to use the chain breaker and riveting tool to break the cam chain. It's a continuous chain. Follow the instructions included with it to set it up correctly with the right anvils and pushpins on it. All we're doing here is we're pushing one of the pins completely through. You can see that I've got a rag to make sure that we don't drop anything down in the motor, and we're using great care not to drop that pin. We're going to pull it off, remove the pin from the tool and go on to the next pin. We're going to push it all the way through as well, and once we do that, the two side plates are going to come off so there are actually quite a few things to catch right here.

Now that your chains broke, take a little piece of wire so we don't lose the chain down in the bottom of the case. Do it on both sides and secure the ends of the chain out of the way. Then we're just going to pull the cam out.

Next we're going to pull the head bolts, remove those. As we're doing these, these have washers on them and once again you don't want to drop anything in the bottom of that engine. Pull them all out together.

Now we're going to move on to these additional head bolts. There are actually three of them. After we get these out of the way, we should be able to pull our head off. Move the cam chain down through. Once again, we don't want it to fall down on the bottom. Pull the head out of the way.

Now we're ready for the cylinder. Work it off. Then I'm going to take a rag and stuff it around the end of the connecting rod so we don't drop any dirt or parts down in. Removing our wrist pin clips, pushing our pin through and pulling our piston off. As you're disassembling, keep track of all your locating dowels.

At this point, you need to inspect your rod and then also your cylinder. As you can see, this one's been damaged. At this point you have two options. You can either have it re-sleeved or re-nickel seal plated. We sent ours off to the guys at LA Sleeve. They reconditioned it and sent it back to us good as new.

Please refer to part 2 for reassembly instructions and to our valve replacement video for valve replacement.