Engine design flaws

It’s taken decades, nay at least a century, to perfect the modern combustion engine, so it’s no surprise that older engine designs had their quirks. Although this is by no means a comprehensive list, there are some core reasons why older bikes have some poor design flaws:

• Excessive crankcase pressure on ventilation system/breather: This occurs in single, parallel 360-degree twins, and narrow angle V-twin engines. Missing or inadequate crankcase ventilation puts a lot of pressure in the crankcase as pistons rise and fall, changing the air volume rapidly. The result? Engine oil leaks past the crankshaft seals as well as other seals and gaskets.
• Vertical crankcase seam: A more inert flaw, engines with a vertical crankcase seam allow oil to continuously sit and exert pressure directly on the seam, which can result in failure and leaks over time.
• Failure due to uneven heat expansion: Some bike engines feature a mix of iron and aluminum top end parts, which unfortunately expand unevenly when exposed to heat, leaving the door open to premature failure and leaks over time.

Sealant failure

Although not all joints require the use of sealer, the machines that did use sealant are most likely going to see it harden and crack as time wears on, not to mention the risk that it seeped into the engine block and is gumming up the smaller passageways.

Gasket failure

Depending on the make and model, the type of material used for gaskets varied. Older Harleys and some British bikes used leather gaskets to absorb excess oil. Unfortunately, without regular care and maintenance the leather naturally hardens and won’t absorb nearly as well, allowing for oil to leak out.

Much like some bikes today, paper gaskets were not uncommon; however, modern paper gaskets are much more sophisticated. With age and use, the paper gaskets from back in the day become brittle and deteriorate over time. Oil leaks stemming from head gaskets are also unfortunately common.

Line failure

Some bikes ran additional lines than most between the engine and the tank, which means more points of potential failure and more lines to maintain.

Frequent Carb Cleaning

Newer motorcycles rely mostly on fuel injection to supply their engines with that all-important fuel and air mix, however the older models use carburetors. Simple in nature, but finnicky in number of small parts and small holes, carbs get clogged and gunked up easily and require regular cleaning and maintenance. Some of the symptoms of a dirty/clogged carburetor include:

• Engine that won’t start or is hard to turn over
• Engine sputters or backfires
• Bikes runs too lean (too much air) with excessively hot exhaust, or too rich (too much fuel), resulting in an overly strong smell of fuel and poor performance overall

Expense

Due to the specific parts required to replace, repair and maintain older bikes, the cost can quickly go up. The older the bikes, the harder it becomes to find parts, especially if you’re looking for original OEM pieces to keep your bike authentic.

Owners that regularly show their antique motorcycles most likely have a set of era- and model-accurate tires in addition to a set of tires for riding. With today’s modern technology, many tire manufacturers such as Coker have been able to recreate the look and feel of those original tires while adhering to today’s tire guidelines. However, if you want a true authentic antique motorcycle then you’re probably going to track down tires manufactured from the year of your bike. They won’t be rideable, but they will look great on your bike for showing purposes.

Black Widow can help with maintaining antique motorcycles

When it comes to doing it yourself, we’ve got garage solutions to make it easier to perform that all-important regular maintenance, or continuous rebuild/restoration.

Our selection of motorcycle lift tables save your knees by raising the bike up to a more comfortable working height. Built-in motorcycle chocks at the front and integrated tie-down points keep your bike secure while you work on it, and removeable loading ramps mean you can (carefully) ride up and onto the table platform, no lifting required.

Our steel and aluminum dollies come in several lengths and are perfect for storing or showing antique motorcycles that are all-original and never ridden, as well as keeping your rideable bikes easy to position in your garage. The kickstand platforms adjust for different makes/models, and lockable casters make the dollies easy to roll across flat, even floors.

Our bead breaker makes switching out tires by yourself an easier process. The extended handle reduces the force needed, and the versatile design can also be used on small equipment tires as well as ATVs.

If at-home maintenance is truly your passion, Black Widow also offers a hydraulic shop press to assist with loosening seized parts, replacing bearings, as well as bending and straightening as needed.

Lastly, whether parking for storage or transport, we have motorcycle chocks to suit most applications. Our Pro Chock is particularly popular for larger bikes, as it can be used in trailers without installation, and does not require a second person to assist while parking.