A magnetic oil filter drain plug and/or an oil filter magnet add one more potential layer of engine protection. Do they work? Residue on the drain plug says yes, but it’s anyone’s guess with the oil filter magnet. They’re cheap enough, so why not? Makes more sense than obsessing about which brand of oil to use…
Motorcyclists spend way too much time obsessing about which brand, type and weight of engine oil to use. There’s only one answer to that question, and it’s in your owner’s manual.
I get a kick out of armchair mechanics who know better than BMW, Honda, Suzuki, etc. engineers when it comes to oil. Look in the book, buy what they recommend and change it when they say. Case closed.
Sure, there are those who swear by Brand X because they’ve been using it for 30 years and never had an engine failure. Oh yeah? When’s the last time you heard of an engine failure due to bad oil? And the question is, as always, “Compared to what?”
So you used Brand X for 30 years and never had a problem. You’d have probably gotten the same results using Brand Y or Brand Z…
Oil manufacturers want you to believe otherwise, but you’re too smart for that, right?
Many motorcycle owners realize this game but may still harbor doubts.
If you still feel like you need to do something to improve on the engine designer’s obvious ploy to get you to use the wrong oil so that your engine seizes soon after break-in, I’ve got just the ticket.
Buy a magnetic drain plug and/or an oil filter magnet. Like those copper rings you wear around your wrist to cure arthritis and improve your natural aura, they can’t hurt. Unlike that copper ring around your wrist, they might just help.
Magnetic Drain Plugs?
Magnetic drain plugs are available for just about every motorcycle (and car) engine made.
There are as many brands, types and sizes as their are engines and probably more, but the Bikemaster brand seems to be the most ubiquitous in the U.S.A.
Bikemaster products are distributed by Tucker Rocky in the U.S., so they’re available at just about every motorcycle shop you can find. If the shop doesn’t have one in stock for your bike, they can easily order it through the Tucker Rocky system and you’ll probably have it in a couple of days.
Cost? About ten bucks. Or, you can buy one here.
If they don’t list a magnetic drain plug for your motorcycle engine, you may be able to measure the thread and the length of your stock plug and find a match.
Just make sure — even if they do have one specifically for your engine — that the thread size is indeed correct and that the magnet on the tip doesn’t make it too long so that it interferes with something in your engine when you screw it in.
On most engines, you should be fine because there’s usually a bunch of room in the oil pan and nothing should be scraping down that close to the bottom, but you never know.
Use the correct crush washer and torque settings and everything should be OK.
This one was installed on the Suzuki DR650 (blog) project bike and it works. It has more residue, or tiny filings, on the tip than we thought it would for such a new engine. Or maybe it’s because it’s such a new engine…
In any case, I’d rather see the filings on the tip of the magnet than I would in the oil.
Oil Filter Magnets?
While you’re at it, why not add a motorcycle oil filter magnet? They also come in a variety of shapes and sizes.
The Bikemaster oil filter magnet shown above is a simple ring shape that has a very strong pull for its size.
This one is designed for cartridge-type oil filters, like the ridiculously expensive ($69.95) Scotts Performance stainless steel cartridge filter shown here (Part number 2615 for the Suzuki DR650SE). It will also work on the standard paper filter.
The idea, of course, is that the magnet will be powerful enough to hold any metal filings on the inside of the canister, preventing them from re-entering the oil system and pathways in the engine.
Does it do anything? Who knows…
You’d have to cut apart the oil filter to see, and even then it might be difficult to tell. But for the price — also around 10 bucks (seems extreme for something so simple) — why not?
Although I don’t know how a piece of metal can be big enough to get through the oil filter, which is claimed to screen down to 35 microns, and then stick to the inside of the canister under the magnet.
But it can’t hurt and — just like that copper bracelet — maybe it has secret magnetic powers that will make your oil last for 100,000 miles! You try making it last that long — not me.
In any case, you’re probably better off blowing the ten bucks on this thing than you are wasting it on some fancy $15.00 per quart oil you don’t need…
There are other types of oil filter magnets; some wrap around the canister type filter and there are also oil filter magnetizers that supposedly magnetize the canister end.
If your oil filter canister sticks out the bottom of the engine, you may be able to simply find a decent magnet of any type and stick it on the end — just make sure there’s enough clearance for whatever works in your situation.
There’s no special magic in these ring-type magnets, and they’re about 5 times more expensive than they should be for what they are.
Conclusion
OK, so I’ve been snide and even a bit facetious here, but seriously, a magnetic drain plug might be a good idea for some added insurance.
At the very least, if you find metal shavings on it next time you drain the oil, you’ll know something is up.
By the way, you may always find some bits of metallic residue on the magnet, which may be normal wear and tear. Just keep and eye on it and you should be fine.
Owner Comments and Feedback
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From “J.D.” (August 2013): “I was sitting on my computer waiting for the pouring rain to stop, as it’s cold and wet where I am in Australia at the moment.
I was looking for a review of stainless steel washable filters and I have been reading your review of the K&P stainless steel oil filters, because I am seriously thinking of getting one of those filters for my car.
It is a 1989 Porsche 928 S4, which has the 5 litre quad cam engine which is also running a rear mounted turbo system which is drawing its oil supply from the engine, so I want the best possible filtration I can get.
Whilst reading about oil filters on bikes, my mind slipped back to my first bike. My first vehicle was a brand spanking new 1970 Honda CL175 twin. That was fitted with a centrifugal oil filtration system.
It was a great system and I wondered why Honda dropped it, do you guys know why?
Every few thousand miles I think it was, I use to open the engine side cover and undo the one retaining screw and pluck out the centrifugal can to scrape out the gunk and give it a quick wash.
It always had a slightly shiny slurry in it which was well compacted in there from the centrifuge action, hence the need to scrape it out.
I kinda wish car engines had that system today, it would have saved us a fortune over the years. I suppose that’s exactly why they don’t use it.
The oil always felt silky smooth with no sign of particles in it, and the engines were a long lived engine if they weren’t abused.
That engine design came directly from the Honda 160 cc twin engines, and they were one of the best engines Honda made. When I bought my Honda 750 years later, I used to wish it had have had the same system instead of the blasted oil filter cartridges.”
From “M.M.” (November 2011): “Was rereading your article on oil filter magnets when I noticed the Scotts Performance Filter. I purchased one years ago for my 2003 BMW K1200GT, which Scotts claim now they don’t make one for my bike?
Mine works fine though, anyway it has a magnet already built into it, and it does collect metal that I clean each time I change my oil.”
From “J.L.W.” (October 2011): “With the price of most motorcycles close to or over five figures, it is completely beyond me why folks get cheap and insist on using automotive oil to save a few bucks a quart for the maybe two oil changes they do a year.
If the price differential is six bucks a quart (which it isn’t) and the oil change requires four quarts (which they don’t) you are going to save 48 whole dollars every year maintaining your ten grand bike. Wow.”
Editor’s Reply: An Airhead owner would faint if he heard you say that! 😉
“J.L.W.” Reply: You’re right about the Airhead guys. They used to say the only thing cheap about a BMW is the owner.
I use motorcycle specific Mobil 1 that runs about $9/Qt mainly because Auto Zone sells it and it’s near my house.
(Editor’s Note: Buy a 6-pack of Mobil 1 V-Twin Motorcycle 20W50 Motor Oil for about 10 bucks a quart delivered).
Every once in a while I see a letter to one of the mc mags where the writer claims they use automotive oil with no ill effects so I guess there’s still a few out there.
I think the reason for the divergence in the spec for auto oil and mc oil is that the anti-friction stuff they put in auto oil doesn’t work well with mc transmissions.
The manual for my H-D calls for oil that is made to be used in diesel engines if you can’t get mc specific oil. It would be interesting to check the ratings on it to see how it compares with the mc oil most manufacturers recommend.”
From “D.T.” (October 2011): “My BMW K1200RS has a magnetic plug for the final drive, implying that at least here, BMW recognizes its value.”
From “S.S.” (October 2011): “While I agree that you will do no harm by using the manufacturer’s recommended oil brand, I disagree that there is nothing gained by switching to a similarly rated API of a different brand.
Specifically, in the case of wet clutch bikes, the shifting feel may be very noticeably improved by trying a different synthetic oil.
For my “99 Triumph Legend, I initially used the Mobil 1 as advised in the manual, but found much better shifting with another premium synthetic.
In fact, I tried three different brands before finding one which gave me the smoothest shifting, and I even tried switching back to see if it was just my transmission wearing in (it wasn’t).
Any of today’s quality oils are going to protect your engine just fine, and if the one listed in the owner’s manual performs well for you, then by all means stick to it.
If your shifting feel is stiff or notchy, however, you may find improvement by switching to another brand. Thanks, as always for a great read!”
From “Walter from Detroit” (October 2011): “I found what I believe to be a better solution at lower cost:
high-power neodymium rare-earth magnets neodymium magnets are ridiculously powerful and when stuck to the side of a typical oil filter they will surely catch more metal shavings than the teensy magnets found in oil-plugs and the low power ring magnets you have in the article.
I bought a stack of neodymium magnets for like $10 on eBay. mine are like 1/2″ x 3/4” and maybe 5 mm thick, the perfect size to stick to the lower-side of my horizontally mounted oil filter.
Pic (below) of my moto magnet setup, you can even see metallic road detritus on the magnet’s exterior that’s accumulated this season.
When it comes time to change the oil/filter, I simply pull this magnet off (it’s super-strong, so it takes a serious tug or pry off with a knife or other lever) and stick to the new one. Some special overpriced “motorcycle filter magnet” is a joke compared to these things.
And for a few bucks, I have a stack of spares to do all my vehicles and give out to friends and family! I do this with my moto and all my cars, too. hope you find this helpful.”
From “C.A.” (October 2011): “The question of whether these are useful depends on whether the oil is routed through the filter before it gets to the engine.
If so, any of the filings will presumably be caught in the oil filter, just as effectively preventing them from entering the engine, as if they were stuck to the oil plug. In my opinion, I’d rather spend the money on a beer or two.”
From “R.D.” (October 2011): “My ’07 DRZ400SM came with one stock. For the record I’m all in favor of magnetic drain plugs. When the bike was new there was always some tiny filings on the tip of the magnet.
Now, at 12,000 miles it’s pretty clean. I change oil every 2,000 with Amsoil 10W40.”
From “T.M.” (October 2011): “With the oil obsession thing I agree but then by the same thinking, if the designers thought a magnetic drain plug was useful, why don’t they put one on the bike to begin with? Do any bikes come with these from the factory?”
From “S” (October 2011): “I think they do work, I have a magnet plug that always has filings on it when I unscrew it for oil changes so they must be doing something. I used to worry about it but it hasn’t increased in time.
Don’t know about the oil filter type magnets though.”