7 Common Problems with the Honda CRF450R (Explained)

Dirt bike enthusiasts are more than familiar with the Honda CRF 450R, the racing edition of the CRF450 motocross series.

And while the CRF450R has rightfully earned its reputation as an ideal choice for a race-ready motocross bike, no dirt bike is perfect.

Here, we’re breaking down the common gripes with the CRF450R, giving riders the inside scoop on what to watch out for.

1. Grips Come Loose While Riding

One problem frequently reported by owners of the Honda CRF450R is loose handlebar grips. When the handgrips slide around your CRF while you’re riding, it reduces control over the bike. Loose grips also cause comfort issues, like numbness in the hands and arms.

Here are a few consumer reports explaining the issue:

“I’m experiencing a loose throttle grip and can’t find anything online on how to fix it. It engages the has good, but the play In the actual grip is really bad. I’ll post some pics because I can’t post a video. It’s a little hard to see, but the grip moves up and down quite a bit, plus left and right. I can’t take it off the handlebars, but there’s a lot of play in it.” – ThumperTalk.com

“Now that it’s warming up around here, I’m having trouble securing my throttle grip. It first broke free a couple of weeks ago (Trying to hold onto the grip while the bike was falling over). Anyway, I tried to clean it out as well as possible with alcohol and then reinstalled it using grip glue from the cycle shop. Let it stand for 24 hours. Now it doesn’t seem as well gripped as it used to, and with a little torque, spins easily…” – ThumperTalk.com

To troubleshoot loose grips on a Honda CRF450R:

• Replace the stock grips with more rigged aftermarket grips.
• Glue the loose grips into place, being advised that you must remove and replace them once worn.
• Use special motocross tape to attach the hand grips more thoroughly.
• Secure the grips in place with metal wiring.
• Inspect the area between the handlebar grips for dirt—clean and reinstall grips as needed.

2. Blows Fork Seals Easily

Blown fork seals can occur on any dirt bike, including the Honda CRF450R. If dirt or debris gets stuck between the fork tube and the fork seal, or if the seals wear out from hard riding, it affects the suspension performance and leaks oil through the seal.

“I blew the fork seals out in five weeks. oil all over my wave rotors. No warranty. Cost 800 dollars to redo forks and shocks. I now love how it handles at high speeds through black diamond trails. Remember, I only weigh 165 with full gear muddy. The stock setup did not work that well, especially with the headshake. also, rg3 clamps made a big difference.”  ThumperTalk

To troubleshoot leaking or worn fork seals on a Honda CRF450R:

• Inspect and clean the space between your fork seal and the fork using a business card or a thin piece of similar, sturdy material.
• If the fork seals are worn and leaking, replace them with new seals immediately.
• For hard offroad riding, upgrade your fork and front shocks with a more durable aftermarket suspension package.

3. Valve Adjustments are High-Maintenance

As a high-performance motocross racing bike, the Honda CRF450R operates at high speeds, generating lots of engine heat. The titanium stock valves take lots of abuse from the high engine temps, can go out of adjustment, and even wear out faster than the valves on other dirt bikes.

“The only complaint I have about the CRF450R (02) is how often the valves need adjustments. I initially rode my 450 for a year before I needed a valve adjustment. Since the first valve adjustment about three months ago, I had to adjust the valves again.” – ThumperTalk

To troubleshoot worn valves on the Honda CRF450R:

• Replace damaged valves with new ones at the first sign of wear.
• Inspect the valves per the service intervals outlined in your owner’s manual, adjusting their clearance as needed.
• Upgrade the CRF450R’s stock titanium valves with stainless steel valves. The stainless valves are more resistant to the high engine temp and will hold their adjustment longer.
• Increase the lifespan of the stock titanium Valves by upgrading the valve seats.
• Adjusting and replacing valves is a technical task that can alter your engine’s performance and lifespan—we suggest having a pro do it if you’re unsure.

4. Frame Cracks Easily

Another common issue reported by Honda CRF450R riders is that the frame and subframe crack easily.  Consumer reports claim the factory frame welding lacks integrity and breaks under heavy use. Other theories claim the frame breaks easily because of the material’s structural integrity.

Regardless of the cause, a weak frame on a motocross bike is an issue. Let’s take a closer look at this common problem:

“CRF450R Broken Frame—I went riding yesterday, and while cleaning my bike up afterward, I noticed that the piece of the frame, near the right lower subframe bolt, that the mid-pipe bolts up to was snapped off, and the bolt that threads into the mid-pipe was also missing. I did bottom out pretty hard several times, but I don’t see snapping it off and taking the bolt along with it. Especially without doing any damage to the exhaust… The bike is a 2005 CRF450R. By the way …, I took a closer look today in the light and realized my subframe broke. It all makes sense now.” – crfsonly.com

“So, as I was installing a new radiator today, I looked down and saw two cracks on the frame. Is this something weldable? I plan on calling Honda, but from what I heard, Honda could care less about issues like this.” – VitalMX.com

To troubleshoot a cracked frame on a Honda CRF450R:

• Regularly inspect the frame for cracks, chips, breaks, and stress marks, especially around the welds and after long, hard-riding days.
• Inspect the frame for straightness.
• If you find a visible sign of damage or a frame section bent and untrue, inspect the bike with a theodolite and re-true it. Repair breaks with a tig-weld.
• If you lack the tools and experience to repair your frame welding, there’s no shame in taking the bike to a pro—your frame is a vital part of the bike’s integrity. ‘
• Take the bike to a professional who can measure and inspect the frame for damages and [air any bends and breaks in the frame.

5. Air Filters Hard to Change

Riders often complain that the air filter on the Honda CRF450R is more challenging to change than the filter on other motocross models. Changing the airbox filter on the CRF450R requires removing the seat and the left-side body cover. Aligning its clips and tabs during re-installation is also tricky.

Here are a few tips to employ when changing the air filter on a Honda CRF450R:

• Follow the owner’s manual instructions and watch a tutorial video on changing the air filter.
• Remove the seat and left side cover before starting.
• Use a vacuum cleaner to remove dust or particles from the air box and the intake tract.
• Apply grease to the air filter sealing area to ensure a tight fit and prevent leakage.
• Drain the crankcase vent tube periodically to remove oil and moisture.
• Have a spare air filter in case the original one is too dirty or damaged to reuse.

6. Chains Wear Fast

The Honda CRF450R’s chain wears fast due to the high-performance nature of racing and the stress the high engine temps put on the chain metal. Dirt and debris between the chain and sprockets and the sprocket size/gearing ratio also cause fast chain wear.

Here are a few troubleshooting tips to slow down chain wear on a Honda CRF450R:

• Clean and lube the chain regularly.
• Adjust the chain tension according to the manual.
• Use quality replacement chains and sprockets that match the bike’s specifications.
• Replace the chain and sprockets at the earliest signs of wear or damage.

7. Shifting Problems

Some Honda CRF riders have reported clutch and shifting issues with the bike, which worn-out or damaged parts can cause. Examples include clutch baskets, plates, shift drums, shift forks, or levers. Other culprits might be the clutch cable, brake, and wheel bearings.

“Honda CRF450R – SHIFTING PROBLEMS— I Just got a CRF450 and had two runs. My last run started to be a problem.

So I couldn’t Un-clutch, start the dirt bike, and lever pin down. Pass the first, and the bike would turn off directly. I thought it was a minor issue, so I replaced the clutch wire and re-adjusted it.

Start it again; pass first or second at no speed. It turned off automatically. I opened the disk casing and checked all my disks. They seemed fine, with no cracks or wear on them. I put the bike on the first gear and tried to disengage the clutch and push the bike…

I can change the gear but can’t move the bike while pulling my clutch lever. I never felt with the bike yet… I believe it’s not disengaging when I pull the clutch lever. Springs? SHIFT DRUM? SHIFT FORK? or something else.” -crfsonly.com

To troubleshoot shifting problems on the Honda CRF450R:

• Inspect your clutch and shifting system per the service intervals outlined in your owner’s manual.
• Adjust the clutch cable as needed; replace it when worn.
• Look for cracks, wear, or strips in the clutch and shifter’s hardware.
• Measure the clutch plate’s tolerances and compare them with the service manual settings.
• Check that the wheels and brakes are aligned, as dragging from the wheels can affect shifting and clutch functioning.  

What Are the Pros and Cons of the Honda CRF450R?

Pros

• Powerful Engine
• Refined Design and Build Quality
• Overall Very Reliable
• Torque Control
• Lightweight Chasis
• Agile Handling
• Fun to Ride

Cons

• Chains Wear Fast
• Blows Fork Seals Easily
• Shifting Problems
• Grips Come Loose While Riding
• Air Filters Hard to Change
• Valve Adjustments are High-Maintenance
• Frame Cracks Easily

What Are Some Alternative Models?

What’s the Resale Value of the Honda CRF450R?

Sources:

450R Crf For Sale – Honda Motorcycles – Cycle Trader

How To Change the Air Filter on a 2021+ Honda CRF450R/RX (youtube.com)