If you’re a dirt bike rider, you know that one of the most important things to keep an eye on is your valves. Over time, they can start to wear down and get out of alignment. If you don’t check them regularly, they can cause serious damage to your engine.
But how do you know when it’s time to check your valves? And what should you look for? Here’s a quick guide to help you out.
- Park the bike on a level surface and remove the spark plug cap
- Remove the seat and gas tank to access the engine
- Unscrew the valve cover bolts and lift off the valve cover
- Inspect the valves to see if they are dirty or damaged
- If they are, use a cloth or brush to clean them off
- 6 Screw the valve cover back on and reattach the seat and gas tank
How to check valve clearance on a 4 stroke Dirt Bike !
How to Adjust Valves on a 4 Stroke Dirt Bike
Valves are an important part of a 4 stroke dirt bike and if they are not adjusted properly, it can lead to poor performance and engine damage. It is recommended that you adjust the valves on your 4 stroke dirt bike every 20 hours of riding or once a year, whichever comes first.
To adjust the valves on your 4 stroke dirt bike, you will need:
-A feeler gauge
-A screwdriver or Allen wrench (depending on what type of locknut is holding the valve adjustment screw in place)
-A clean rag
-Engine oil
First, you will want to remove the spark plug from the cylinder you will be working on. This helps prevent the engine from accidentally turning over while you are adjusting the valves.
Next, locate the valve cover(s) and remove them so that you can access the valves. On most 4 stroke dirt bikes, there will be 2 intake valves and 1 exhaust valve per cylinder.
Using your feeler gauge, check the clearance between each valve and its corresponding rocker arm.
The clearance should be checked at both the top and bottom of each valve’s travel. To do this, rotate the crankshaft until the piston is at top dead center (TDC) for that particular cylinder. At TDC, both intake and exhaust valves should be fully closed.
Once you have verified that both valves are indeed closed, insert your feeler gauge between one of the rocker arms and its corresponding valve stem at either end of its travel to check for clearance. Do this for all 3 valves in that cylinder before moving on to checking clearance in another cylinder.
If any of the measured clearances exceed specifications given by your bike’s manufacturer (which can usually be found in your owner’s manual), then adjustment is necessary.
For example, if specified clearance for an intake valve is 0.006″-0.010″ and yours measures 0.012″, then it needs to be adjusted down accordingly using one of these methods:
Method #1: If there is an adjustable locknut holding down Valve Adjustment Screw…
Credit: blog.pro-x.com
How Do You Check a Dirt Bike Valve?
Valve clearance is one of the most important aspects of maintaining a dirt bike. Incorrect valve clearance can lead to a number of problems, including loss of power, engine damage, and difficulty starting the engine.
There are two types of valves on a dirt bike: intake valves and exhaust valves.
Each type of valve must be checked separately. To check the intake valves, start by removing the spark plug from the cylinder you’re going to be working on. Next, rotate the engine so that the piston is at top dead center (TDC).
This can be done by either finding the TDC mark on the flywheel or by carefully watching through the spark plug hole as you turn the engine over until the piston is at its highest point.
Once the piston is at TDC, remove the valve cover(s) and look inside. You should see both intake valves fully closed.
If not, there’s a problem with your valve clearance.
To check exhaust valves, begin by removing the muffler or silencer from your bike (if it has one) to give you better access to the rear cylinder head. Again, rotate the engine until you reach TDC and remove the valve cover(s).
You should see both exhaust valves fully open at this point. If not, there’s an issue with your valve clearance that needs to be addressed.
How Do You Know When Your Dirt Bike Needs New Valves?
If your dirt bike is running a little rough, it might be time to check the valves. Over time, valves can become worn or damaged, affecting engine performance. Here are a few signs that your dirt bike might need new valves:
1. Reduced power and acceleration. If your dirt bike isn’t accelerating as quickly as it used to, or doesn’t have the same power when you open the throttle, worn valves could be to blame.
2. Difficulty starting.
If your dirt bike is having trouble starting up, or takes longer than usual to start, this could also indicate an issue with the valves.
3. Higher fuel consumption. Worn valves can cause your engine to run less efficiently, resulting in higher fuel consumption.
4. Excessive exhaust smoke. If you notice excessive exhaust smoke coming from your bike’s tailpipe, this could mean that the valve seals are worn and need to be replaced..
5 Knocking noise from engine .
How Do I Know If My Valves are Out of Adjustment?
If your engine has valves, it’s important to keep them in good working order. Over time, they can become out of adjustment, which can lead to poor performance and decreased fuel economy. There are a few telltale signs that your valves may be out of adjustment:
1. Your engine is running rough or misfiring. This is usually the first sign that something is wrong with your valves. If one or more of the valves are not opening or closing properly, it can cause the engine to run rough.
2. You have increased exhaust emissions. If your valves are not adjusted properly, it can cause an increase in exhaust emissions.
3. Your fuel economy has decreased.
If your engine is not running as efficiently as it should be, it will use more fuel than normal. This will show up as a decrease in fuel economy.
4. You’ve noticed a drop in power or acceleration.
If your valves are not adjusted properly, it can lead to a loss of power or acceleration because the engine is not able to breathe as well as it should be able to .
How Do I Know If My Motorcycle Needs a Valve Adjustment?
If you’re unsure whether or not your motorcycle needs a valve adjustment, there are a few things you can check to be sure. First, consult your owner’s manual. Many manufacturers recommend that valves be adjusted at certain mileage intervals.
If you’re past due for an adjustment, it’s likely that your valves need attention.
You can also check for telltale signs that something is amiss with your motorcycle’s valves. If the engine is running rough, missing, or backfiring, it could indicate that the valves are out of adjustment.
Also, if you notice an increase in fuel consumption or exhaust emissions, those could also be signs that it’s time for a valve adjustment.
Of course, the best way to know for sure is to take it to a qualified mechanic who can diagnose the problem and make the necessary repairs.
Conclusion
It’s important to check your dirt bike valves regularly to ensure they’re in good working order. Here’s a step-by-step guide on how to do it:
1. Remove the spark plug and unscrew the valve cover cap.
2. Use a feeler gauge to measure the clearance between the valve stem and rocker arm.
3. Adjust the clearance if necessary – refer to your bike’s manual for specific instructions.
4. Screw the valve cover cap back on and replace the spark plug.