How to fix your motorcycle engine — the hard way

  • July 28, 2021

With most motorcycles now built with the same components that power their engines, you probably don’t think twice about how your engine looks.

You may even take it for granted.

But if you’ve ever wondered how your motorcycle’s engine is supposed to work, you may need to get serious.

For the sake of this article, we’re going to show you how to fix the problem, without going overboard.


Install a new valvetrain The simplest fix is to install a new camshaft valvetrain.

That means removing the old camshank and replacing it with a new one.

That’s the easiest and most obvious fix, but there’s no guarantee that it will fix the issue.

If you’re in the market for a new engine, look into buying a new cylinder head or cylinder heads.

These may help.


Rebuild the pistons You can rebuild your pistons with a bolt-on valvetrain, which has a camshuster or camshunter.

It doesn’t have to be expensive, but it’s easier to get parts for, and the parts can be easily swapped out.

If your engine has a large block, that may be a good option, but the engine can’t be easily replaced without removing the entire block.


Install new oil coolant A new oil cooler is another possibility.

It’ll require replacing the oil pump, and some of the seals on the crankcase and bearings.

You’ll need to buy a replacement pump.


Replace the throttle body If you’ve replaced the throttle bodies, you’ll need a new shaft.

Replace both the throttle and the shaft.

That should take care of the throttle.

However, if you’re rebuilding the engine, you won’t have the shaft, and you’ll also need to replace the bearings on the transmission shafts.


Replace bearings A new set of bearings is a good way to start.

You can replace the ones on the engine’s cylinders, or the ones that support the piston heads.

You could also replace the bearing on the camshanks and crankcase, but they’ll need replacing.

The bearings that you replace are made by Bosch.

It’s worth it to buy the bearings from the dealer.


Install an oil filter A good oil filter is a piece of plastic that’s mounted inside the engine bay.

The seal around the filter is also removable, so you can swap it out if needed.

You should have the oil filter installed before you rebuild your engine.


Install the throttle cable bolts A new bolt is a great way to get bearings and throttle cables back together.

This is the same as replacing the throttle shaft.

It might also be a better idea to replace some of your engine’s hardware if you can.


Install fuel injectors A new fuel injector will be needed to fill the injectors and transfer fluid.

You might have to buy an injector.


Install spark plugs If you have a cam chain, a new spark plug is also a good idea.

The bolt that you put on the chain is usually a part of the cam chain.

You won’t need to remove the cam, and there’s a good chance you’ll be able to replace it without removing your transmission.


Install seals on your transmission and crankshaft A new seal is a common repair for a gearbox.

You don’t need a replacement, but a new seal can save you from having to rebuild the entire transmission.


Install oil pressure sensors There are some new sensors that can be installed on your motorcycle.

You will need to take your transmission apart and install them.

If that’s not possible, you can install oil pressure sensor bolts on the front of the transmission.


Install shock absorbers A shock absorber will be used to help protect your bike against the high impact that comes with running on gravel.


Replace brake pads There’s a few different kinds of pads available for your motorcycle, and many of them come with brake pads.

You want to replace them all, so check out the list below.


Install brake pads with different pressure sensors One of the most popular pads for brakes is the Bosch Brake Force Sensing Sensor.

It will detect when you’re braking and help you find the correct braking pad for your needs.


Install airbags There are airbag inflators for most of your motorcycles, but some of them don’t.

If this is the case, install an airbag with a pressure sensor and a brake pad.


Install rear shocks It’s important to remember that your bike has a different suspension setup from that of your road bike.

That suspension setup needs to be installed differently to work correctly.

Some suspension systems, like coilovers, have different settings for the shock absorbs and the brakes.

If these different settings are different on your roadbike, you should replace them with different suspension settings on your mountain bike.


Replace rear tires The rear tires of your motorcycle are supposed to be replaced at least