Honda CB350 • CB360 • CB450 • CB500T • CB550 | Parts • Info • Support
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Answers and specifications to the most frequently asked questions. If you don't see the answer to your specific question contact us directly.








Do you ship internationally?

Yes! International are welcome, and we do ship all over the world regularly. For a shipping quote simply put a shopping cart together, press the "proceed to checkout" button, and enter your shipping address. Once your postal code is entered you should get a quote based on the weight of the items in your shopping cart.

You may feel like the quote is on the high side, and it may be. The final shipping cost will be calculated based on actual weight and if there is a balance you will be refunded the difference.

All orders are shipped via USPS First Class and Priority International Mail. Unfortunately, tracking is not available on all international orders, or when it is available, it is not always accurate or updated once the package leaves the United States.

The delivery date cannot be guaranteed due to unpredictable delays in customs or with your local postal service. The typical shipping time to most countries is around 2 weeks, but may be as long as 6 weeks. Insurance is not available and we cannot refund for lost, unclaimed, or undeliverable packages.

All international shipments will be marked as merchandise. Depending on your local laws, there may be duties, taxes, or other fees due before you can receive your shipment and may be held by your local post office until duties have been paid. These fees are beyond our control, and Common Motor is not responsible for these charges. Please be sure that you understand any customs fees you may be responsible for. If a package is returned to Common Motor with unpaid customs fees, the buyer will be given the option to receive a refund, minus the cost of shipping, or the buyer can repay shipping to resend the package with the understanding that the intended receiver will be required to pay the customs fees for delivery to occur. We are not responsible for any customs fees.

How do I return my item?

You can return your items with in 30 days of purchase for a refund or store credit.

Mail to:
CMC Returns
(put your order number here)
1615 Branard St.
Houston, TX 77006

Please include in the return package a copy of your invoice with a brief note about the reason for your return. When we receive and inspect the kit we'll notify you and issue you a refund.

Do you have this obscure / oddball part?

Simply ask us using our contact form. If it's for a Honda 350, 360, or 450 there's a good chance that we do. We carry a wide variety of parts that aren't necessarily on the site yet so if there something you're looking for and don't see it just ask.

I see that you offer a "core" program. What is that?

In the automotive parts world, it is common to see an additional fee associated with a part purchase called a "core deposit." This deposit is to ensure that the original, worn out part known as the "core" is sent back to the seller.

Specifically, the "core" refers to the main metal casting that can be reused, reground, or rebuilt into a fully functional part that meets the original factory spec. Because most OEMs no longer manufacture parts for vintage motorcycles, it is necessary to have cores to rebuild. Even if an aftermarket company "re-pops" a part, it is rare for this replacement to match the original's quality.

The way the core exchange program works is that when you send us your existing part, and it is in rebuildable condition, you will be sent a rebuilt replacement and refunded the core deposit. If you simply need a part and don't have an existing "core" to exchange, you will receive a core charge on top of the price of the part. This exchange allows us to have a supply of parts to rebuild, which in turn helps all of us keep our bikes running well into the future.


My clutch is "popping" when I squeeze the lever, and I've adjusted the cable at lever as much as I can. How do I adjust the clutch?

The cable housing barrel adjusters are used only to remove or add slack to the cable, not to adjust the clutch itself. The clutch adjustment is made where the clutch cable enters the engine. The precise adjustment for your bike differs from model to model so reference our 'Manuals' page.

  • Page 152 of the Honda CB350 Tune Up and Adjustment Guide
  • Page 22 of the Honda CB360 Tune Up and Adjustment Guide
  • Page 153 of the Honda CB450 Tune Up and Adjustment Guide

First, we turn the lever barrel adjuster all the way in to give us slack in the cable. Next, down below where the clutch cable connects to the engine block, we set the clutch per the manuals (listed above). Finally, turn out the lever barrel adjusters to remove some slack from the cable until 1/4 to 1/3 of the lever's overall travel is free play. You want your clutch lever on the looser side than too tight.

What type of cleaning products should I use when rebuilding my engine/carburetors/bike?

For general degreasing we use Black Scorpion and Purple Power, but any water-based degreaser should do the trick. Our parts washer uses specific parts washer fluid that is a petroleum-based industrial strength solvent. The fluid is similar to mineral spirits, which is also a good general solvent to use. It is very important that you use nitrile gloves in the parts washer and replace them if they tear, as solvents will cause chemical burns. For the ultrasonic cleaner there are a number of different solutions that will work, but we've had good luck with water, vinegar, dish soap, and salt.

When do I use anti-seize, and when do I use Loctite?

In general, apply an anti-seize compound to threads of bolts that need periodic removing, particularly in the case of steel bolts threaded into an aluminum casting, and bolts that experience extreme temperature fluctuations such as engine side covers and exhaust mounts.

Often referred to by the brand name "Loctite," thread locking/retaining compound is used less often than anti-seize, and mostly on parts that experience intense vibration. Any screw, nut, or bolt that needs an extra level of security and will not require periodic removing is a good candidate for Loctite. There are several varieties (colors) of Loctite; we tend to use the blue flavor.

How do I know what model or year bike I have?

The sub-model (k0, k1, k2, etc.) is a far better indicator regarding part fitment and sub-model specific specs. Production year is loosely affiliated, but doesn't necessarily correlate to a certain k model. It's good to know your year (bragging rights or whatever) but for parts, know your sub-model. We try to keep our model charts accurate in our part descriptions for help.

The VIN number should be stamped in the ID plate riveted to the steering tube behind the headlight, along with the production month and year. The VIN should also be stamped into the frame near the ID tag. Every engine stamp will have the bike model and E for engine ex: CB350E-xxxxx. This number was not matched to the frame from the factory, so it shouldn't be used to identify your bike.

Each model has different rules for determining the sub-model from the VIN number, but they all share the same structure with the model, followed by a dash, then a series of numbers (ex. CB450-3008956). Below refers the the first digit AFTER the dash in the VIN number:

  • Honda CB / CL / CJ 350 k0 - k5 (ex. CL350-3003456)
    • k0 and k1 begins with -1
    • k2 thru k4 begins with the submodel -2 for k2, etc.
    • 350G is the k5 and begins with a -5
  • Honda SL 350 k0-k2
    • k0 begins with -1
    • k1 begins with -2
    • k2 begins with -3
  • The Honda CB / CL 360 did not have many variations. It mostly remained the same throughout the production run. The exception being the early 1974 CB360 identified by a front drum brake. These are pre-recall chain tensioner models, and are identified by two dots above and below the dash in the engine stamping if the recall HAS already been done.
  • Honda CB /CL 450 k0-k7 (ex. CB450-3008956)
    • k0 is the black bomber and begins with -1
    • k1 begins with -3
    • k2 begins at -3008956 including higher numbers
    • k3 begins with -4
    • k4 begins with -41
    • k5-k7 begins with the sub-model -5 for k5, etc.
  • The Honda 500T was built in one batch and sold for 2 years. They're mostly all the same.
  • Honda CB500 (4 cyl)
    • k0 begins with -1
    • k1 begins with -2
    • k2 begins with -21
  • Honda CB550 k and F (ex. CB550-2106456)
    • k0 begins with -1
    • k1 begins with -12
    • 1976 CB550k2 begins with -123 (in 1976 Honda began designating models by year)
    • 1977 CB550k3 begins with-20
    • 1978 CB550k4 begins with -21
    • The CB550F did not change much from year to year.


What size chain / sprocket do I need?

It depends entirely on the number of teeth on your existing sprockets and the number of links in your existing chain. Start with counting all of that. This video may help.

If you're keeping your gear ratio the same, simply order replacements that match the tooth/link count on your current parts. If you're changing your gear ratio there are a few things to consider.

As each link alternates between an inner and outer link, any variation in chain length will be a multiple of two.

A larger sprocket (either front or rear) with the same length of chain will pull the wheel forward in the axle dropout. The opposite applies for a smaller sprocket. Depending on where your wheel sits in the slot, you may be able to go up or down in sprocket size without changing your chain length.

Chain length and wheel position varies bike to bike. The good news is you can return the unused chain if you end up needing a different size. You can error on the longer side and cut the chain down if need be. We carry chain breakers if you don't have one already.

There are a few known factory sizes that might help:

Factory Chain Lengths Based on Factory Sprocket Tooth Count

  • CB350 - 16 F / 36 R = 94 link
  • CL350 - 16 F / 38 R = 96 link
  • CB360 - 16 F / 34 R = 94 link
  • CL360 - 16 F / 34 R = 94 link
  • CJ360 - 16 F / 33 R = 98 link
  • CB450 - 15 F / 35 R = 92 link
  • CL450 - 15 F / 35 R = 92 link
  • CB500T - 15 F / 33 R = 96 link
  • CB550K - 17 F / 37 R = 100 link
  • CB550F - 17 F / 37 R = 100 link


Can I pull my starter without removing my side cover?

Unfortunately there's no way to remove the starter without removing the side cover, as the starter drive gear and chain will just drop into the engine. Consider the side cover gasket when doing this job, as you may need a fresh one depending on how it was treated the last time it was removed.


What's with the two different headlight kits?

So the 3043 kit ($90 with bucket) is a universal aftermarket kit that fits a large number of bikes, may require slight mounting modification, but still looks pretty darn stock. The parts aren't necessarily interchangeable with the factory headlight assembly.

The 3044 ($100 kit without bucket) fits in the original factory bucket replacing the sealed beam with a lens and a replaceable bulb. The lens requires some modification on our end to fit the stock side-to-side adjustment screw hole in the factory trim ring, hence the additional cost. We made a video explaining how we do it and why.

In short, you need the $100 one to keep your stock bucket.

My bikes not charging/holding a charge. Is my stator bad?

Stator coils are not the most common culprit in the charging system. The two most common gremlins in the charging system are a faulty battery (common with Lead Acid batteries) or a bad regulator/rectifier. See if this video doesn't answer some of your questions.

There is always a chance you have a bad battery and that your stator is fine. The best way to test this would be to fully charge your battery, measure the voltage. Put it in the bike and get it running, and measure the voltage as the bike is running. If it keeps going down well below 12-13v it's the charging system not performing. If it stays fairly constant while it runs your battery might be faulty, which is not uncommon.

Similarly, if you fully charge the battery and let it just sit for a few days and the voltage drops considerably, then you should replace the battery.

I would like to use a capacitor, lithium ion, a smaller or no battery. What do I need to do?

The truth is these ignition systems were designed for use with a battery. We prefer AGM (absorbent glass mat) type. Unless you really know what you're doing, we don't recommend a capacitor (or battery-less) system for the bikes on our site.

We get a number of questions regarding the use of Lithium ion batteries in the old Honda twins due to their small physical size. Li-ion batteries are generally more sensitive to charging voltages. For this reason we do not recommend the be used for these specific bikes. If you do choose to try a Li-ion battery, make sure to test the charging voltage range on your bike and consult the battery manufacturer to ensure your bike does not exceed their specs.

The regulator/rectifier combo unit we offer is not MOSFET, in case that is a requirement for a specific battery you may want to use.

If you really want to go smaller, the closest, working, approach we've found is getting a physically smaller SLA battery, generally used on alarm systems, etc. It can be fastened up under the seat where it's out of sight. Anything over 5 Ah should work.


My 360 air filters are different that the ones you carry. Will yours work?

There were two, slightly different, filter boxes used on the 360's - an early and a late style. Many folks swap out the late style boxes for the early style because the filter elements for the late style are no longer available.

The filters we have are the early style, which have a simple flat sided metal cover that pops over them. The late style filters use a convex shaped two piece box with a smaller rectangular filter that rests inside the box.

A late style bike can be converted to use an early style filter. You'll need both filters, early style covers (used) and requires fabricating a small bracket for the rear bolt to mount to the frame.

Do you have fuel line?

The fuel line we carry is a nice clear/yellow polyurethane tubing that stays stretchy and is more crack-resistant than the black automotive line. We all use it on our bikes, usually held on with squeeze-type hose clamps or small zip ties.

It is NOT the same clear vinyl tubing you would get from the hardware store, which will crack over time. 

How do I install my new carb diaphragm?

With each carb diaphragm we sell we email you, the customer, a PDF instruction sheet on how to install them. Should you have more questions this video shows the installation process.

What size jets do I need?

As for jetting... there is not one universal answer for your bike. Think of your bike as a birthday cake... Jetting is like lighting the candles; the very last thing that you do. Carb rebuild, sync, standard tune up (cam chain, valves, ignition timing) must all be done first. Only then can we start to tackle the jetting question. Some quick tips on jetting tips.

The main jet has an effect on the top 1/3 of the rpm band (6000 to 9000 RPM). The bike should pull strong from idle to 9k without any issue. If it revs hard then hits a wall, say at 7k, then you are too lean. This can be verified by checking the color of the tips of your spark plugs. They will be fairly clean and almost white. If the bike pulls to about the same rpm but has trouble doing it then it is rich. If you put the choke on 1/2 way you will get the same effect. Spark plug tips will be black and sooty. Ideally the plug tips should be tan in color for a proper mixture and the bike should pull to top RPM smoothly.