How Often Should You Change the Oil on Your Dirt Bike?

I was thumbing through the manual for my CRF450R (because I’ve got nothing better to do) and I found something interesting that I thought I should share. Most guys at the track or up on the mountain, say that you should change your oil after every-other race or after 5-6 hours. Turns out they’re being more obsessive than me… and that’s saying something.

The dirt bike manual that I have says that you should change the engine oil, oil filter, and transmission oil after every six races, or every 15 hours. However, it also says that you should inspect the oil after each race, or every 2-3 hours.

Of course, the type of rider you are plays a significant role in how strictly you need to stick to this maintenance schedule.

If you’re riding close to the limit of your bike and slipping the clutch on every corner then you’ll need to make sure to change the engine and transmission oil as often as recommended. But if your normal riding day consists of putting around well groomed trails and gravel roads while never slipping the clutch… you’ll be fine pushing the intervals to the limit.

I’ve even read on different forums where guys will change their oil after every ride. While that is definitely not a bad idea, it probably isn’t necessary. There is one thing to note though – if you change your oil more often, you don’t have to change the filter as much… which, I suspect, is why many guys change their oil at shorter intervals.

How to Inspect and Add Oil

Checking the oil and adding more (if needed) is fairly straightforward. Once you’ve done this a few times, it will become second nature and it only takes a few minutes. Here are the steps:

1. Start your bike and let idle for 3 minutes
2. Turn off and let sit/cool off for 3 minutes
3. While letting it cool off, make sure your bike is standing straight up (level)
4. Remove the fill cap (it’s also the dipstick) and wipe the dipstick clean with clean rag or shop towel – these work great
5. Insert the dipstick back in WITHOUT screwing it in and then remove and check level
   • If the oil is at or above the upper level, do not add oil
   • If the oil is at or below the lower level, add oil (do not overfill)
6. Reinstall the fill cap (dipstick)
7. Repeat steps 1-6 is recommended
8. Inspect the O-ring (replace if necessary)

That’s it. It might look/sound like a lot but it really isn’t. Plus, it’s vital you learn to do this regularly. Not that dirt bikes are known for burning oil, but you sure don’t want to do on a day-long ride with an insufficient amount of oil.

How to Change Oil on a Dirt Bike

Just like checking the oil, changing the oil becomes routine as well. Although it will take more than a few minutes, it still is only about a 20-30 minute job. Here are the steps:

1. Start your dirt bike and let idle for 3 minutes
2. Turn off and stand bike up, making sure it is level
3. Remove the fill cap (dipstick)
4. Place an oil pan under the engine
5. Remove drain bolt and sealing washer
6. Holding the kill-switch: kick the bike over 5 times (or so) to completely drain oil
7. Apply a bit of oil to the drain bolt  threads and sealing washer and reapply using a torque wrench (like this)
8. NOTE: we’re not filling it up just yet
9. Remove the oil filter
   • You probably have an engine guard covering the filter cover – remove both
10. Carefully remove the filter, O-ring and spring
11. Apply a little grease to the end of the spring on the filter side and then put the spring in the new filter
12. Place the spring against the engine and install the new filter with the rubber seal facing out
    1. Should be a side marked “OUT-SIDE”
13. Add a oil to the O-ring (might need a new one if worn or damaged) and install the filter cover and engine guard (again, using a torque wrench)
14. Fill the crank case with the appropriate amount (.66 qt after changing oil and filter) as well the appropriate type of oil (this is probably the best)
15. Install the fill cap (dipstick)
16. Check oil level
    1. Do this by following steps 1-6 in the above section on checking oil

NOTE: Don’t be dork and just empty your motor oil on the ground. Pour oil into a suitable container and dispose of responsibly.

What Oil Does a 4 Stroke Need?

There are a few things to look out for when choosing which oil to use. At the top of the list are the API classification and the viscosity.

Viscosity: SAE 10W-30 (colder weather) or SAE 10W-40 (warmer weather)

API Classification: SG or higher – except oils labels as “energy conserving” or “resource conserving” on the service label. However, 4-stroke engine oils that are rated equal performance to SJ (still not labeled “conserving”) are the ones that are recommended.

The “S” rating sounds a little complicated, but it’s not. Its like the alphabet… A, B, C, D… you get the idea. Except it does skip a few.

Having said that, I like to stick with name-brand, dirt bike oils. Since I ride a Honda CRF450R, I just go with Pro Honda GN4 10W-30 (view on Amazon) for the motor oil and the Honda Transmission Oil – 80W/85W (view on Amazon) for the gear oil.

I have, however, ran Motul’s synthetic oil (view on Amazon), which is even better than the Honda brand oil… but more expensive.

What Oil Does a 2 Stroke Need?

It’s been a while since I owned a 2-stroke. Maybe 2000-2001… I don’t really remember. I had a new 1999 YZ250 that I liked but eventually went back to 4-strokes when I got a new 2001 YZ426F <- really fun bike!

Honestly, I couldn’t tell you what oil I ran in the Yamaha. But, I know a lot of guys run (and like) the Maxima Castor 927 2-stroke oil.

For gear oil, the Maxima Hypoid Gear Oil is a solid choice for 2 or 4-stroke dirt bikes.

What Happens to an Engine Without Oil?

Good question. It breaks. 🙂 Here’s a cool video showing the difference between a motor with oil and a motor without.