MC Tested: Tusk Magnetic Drain Bolt for Motorcycles

An unfortunate misrepresentation.

Tusk Oil Drain Bolt
Tusk's Magnetic Oil Drain Bolt is meant to be used across a multitude of different models, but there's one big problem...Photo: Brody Cox

In most types of racing, it's a necessity to drill the heads of any bolts that retain liquids, such as oil and coolant drain bolts. In the event that one should work its way loose from vibration, the resulting fluid draining out onto the track's surface could spell disaster for you and other riders.

It was for this reason that I decided to replace the stock drain bolt on my 2003 Kawasaki KX65 that I had just finished building into a mini-gp bike for an upcoming road racing series. I decided to snag one of these Tusk drain bolts that was pre-drilled from an online site, and a few days later it ended up on my doorstep.

Tusk Oil Drain Bolt
Here's the drain bolt as it arrived to me—note the 'hardened steel construction' label.Photo: Brody Cox

Tusk’s own website advertises this product as being an O.E. replacement drain plug with a built-in magnet to catch any metal shavings or contaminants that end up in your oil. They also claim that it’s made from “Durable, hardened steel construction,” and go on to suggest that it’s an easy way to prolong engine life and monitor the wear of internal components.

Swapping the drain bolt from the stock part to this pre-drilled one was last on my list of things to do before the race, and I had since already changed out the transmission oil previously during a rebuild. I leaned my bike over on its side, so I could quickly swap in this new drain bolt without draining any of the fresh oil.

Tusk Oil Drain Bolt
The magnet, visible from this angle, protrudes into the case and collects metal shavings before they work themselves into oil galleys and bearings.Photo: Brody Cox

Initially I noticed that the Tusk drain bolt was far lighter than the stock drain bolt. I checked the package for any specific instructions (of which it had none) so I referred to my service manual for the proper tightening torque. I set my calibrated torque wrench to the specified 15 lb-ft and began tightening. However, I was stunned when the head of the Tusk drain bolt suddenly sheared off just as the torque wrench made the audible click notifying me that it had reached the target torque value.

To say I was frustrated would have been an understatement. I glanced down at the head of the bolt, cleanly sheared off from the thread body, now lying on the ground in a puddle of oil that was rapidly beginning to leak out of the bike, slipping past the rest of the bolt that was now snapped off cleanly in my engine case. I happened to notice at this point that the head of the bolt was far lighter than expected, which lead me to the startling revelation that it was made up of cheap aluminum, as opposed to the ‘durable, hardened steel’ that was stated by Tusk.

Tusk Oil Drain Bolt
Imagine my horror when this was what I saw! The head of the drain bolt sheared off at the slightest hint of torque being applied. Luckily, I was able to remove the inner magnet and used a flat-blade screwdriver in order to twist the threaded body back out. I'm still amazed there was no damage to the threads on the engine case half!Photo: Brody Cox

I ended up having to slide the inner magnet out carefully from the thread body carcass left in the engine, and then used a flat-blade screwdriver as a punch to remove the threads. Luckily I was successful, and there was no further damage to the engine case half. The obnoxious thing was, I had failed to realize this entire time that the stock drain bolt was already drilled for safety wiring.

I reached out to Tusk multiple times for an explanation of why their product was advertised as being made from hardened steel, when in reality it was cast aluminum, but they avoided commenting on the issue, instead pressing me to simply request a refund or an exchange.

Tusk Oil Drain Bolt
Not cool, man, not cool! It's one thing to have a flaw in the consistency of a casting, but it's another thing entirely to claim the product was made out of hardened steel when it very clearly isn't.Photo: Brody Cox

While I’ve used other products from Tusk in the past and have been very happy with them, I can’t say the same for this drain bolt. Aside from the headache of having to fix a rather daunting problem at the last minute, I was unhappy that it had been advertised as something it was not. For that reason, I can’t recommend the use of this product in any way, shape or form.

Tusk Oil Drain Bolt
I'd really rather this not happen to anyone else. It was especially frustrating to find out later that the original O.E.M. bolt I was looking to replace with this Tusk bolt was already drilled for safety wire. Whoops.Photo: Brody Cox

Tusk Magnetic Drain Bolt
Price: $6.99 (plus shipping)
Contact: rockymountainatvmc.com
MC Grade: F
Verdict: There's no way I would want anyone else to have to deal with a sheared-off drain bolt due to cheap construction. You may not be as lucky as I was, and if you aren't, it's a very expensive fix!