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Yamaha-Powered Oddball: 1980s Tri-Magnum

The Tri-Magnum is one unusual vehicle and normally we see them being powered by a Honda Goldwing drivetrain, this one is a little different at being a little different. This 1980s Tri-Magnum can be found here on eBay in Lodi, Ohio and the current bid is just over $2,000.

The seller says that this is a true barn find, what kind of cool farmer owned this one?! Kidding, not all barn finds were actually in a barn-barn, as in farming-related barns. It sounds like they aren’t sure what year it is but the Tri-Magnum was first shown on the cover of Mechanix Illustrated in 1983 so it can’t be earlier than that.

We’ve seen a few Tri-Magnums here in the past. Jamie showed us one a couple of years ago and I ran across one in the fall of 2016 that was similar looking to this one but in much nicer condition, and it also had the preferred Honda Goldwing engine, unlike this Yamaha-powered version. Although, the first ones were powered by a Kawasaki KZ900.

The interior, such that it is in these small three-wheelers, looks good but not great. I can’t imagine that the driver can be 6′-5″ tall and get their legs under that steering wheel and between the shifter, wow, that’s tight.

I’m a rabid Yamaha fan/fanatic and this one is powered by a Yamaha Maxim XJ650 four-cylinder with 73 hp. It’s weird seeing the whole gas tank and everything under the “hood”. The Honda Goldwing which was later used because of its reverse gear among other benefits, didn’t have much more horsepower but I’m guessing that it may have been smoother and quieter. I have never owned a Goldwing but I know that a few of you have. Have any of you owned or even seen a Tri-Magnum in person?


  1. Nevadahalfrack Nevadahalfrack Member

    Never seen one before. Thank you, Scotty!

    Like 5
    • Ike Onick

      And if we are really good and finish all of our vegetables, we will never see one again! I expected the caption to read “Where’s The Rest of Me”

      • Terry R Melvin

        Looks like a negative copy of a Reliant Robin!

        Like 1

      Same here.

  2. TJ

    Many years ago, Popular Science published an article on a similar homemade vehicle, called the “Trimuter”. I bought the plans intending to build the car, but never did. Just threw away the plans a few years ago with the magazine, but it looked very similar to this one.

    Like 3
    • Milt

      It was Popular Mechanics. The design still kinda-sorta doesn’t look that dated. I bought the plans for it and realized quickly that it was way above my skill set. I still have the assembly manual. Anybody want it?

      YouTube video driving on the street:

      Like 3
      • Julian

        Yea sure, a couple of my friends and I hang out each weekend to work on cars and bikes. We would love to take a stab at building it.

      • Milt

        Hey Julian, if you want the manual, contact me through my Parilla website found on this BF entry:

        Scroll down to the bottom for the e-mail link. Just pay the postage.

        Like 1
  3. Victor Anderson

    These look cool and all — but at the end of the day it’s not much more useful that a motorcycle. No heat, no A/C, no fan motors, no wipers, no storage, etc etc etc.
    I guess you wouldn’t get wet if it was raining (unless it leaks — which wouldn’t surprise me) – but even so with no wipers ya still can’t drive it in the rain.

    Like 2
    • John Karlsson

      Rainex might work.

      Like 4
    • grant

      How hard can it be to raid the wiper motor off of an old boat and bolt it on?

      Like 6
  4. DayDreamBeliever DayDreamBeliever

    Looks like it has not run in very many years. Likely locked up and in need of pretty much a total redo. I’m thinking that a bike replacement is in order.

    As far as reverse goes, I’d wager that the electric motor seen with a chain drive at the back behind the rear wheel is for that purpose. Likely that it levers a roller onto the tire, to back out of spots where needed. A wiper could be added. With a water-cooled more modern bike for more power, a heater wouldn’t be too much trouble either. AC is a different struggle entirely.

    I am curious what the seller has as a reserve. In this condition, I think $2500 would be all-in?

    Like 5
  5. The Crow Flies In Square Circles

    You can still buy the plans to build one of these. The company, surprisingly, is still around. They have plans for all kinds of interesting vehicles. I think the main thing that the plans have to offer, though, is that they teach you how to make things with fiberglass.

    Like 6
    • kevin piepkorn

      if you have a link to the company I would like it.,thanks Kevy

  6. Shawn Fox Firth

    Cool – How about a Yamaha V-Max swap ..Or Great platform for an E/V swap .

    Like 5
  7. Kevin Edeline

    It would fit right in at the UFO Festival in McMinnville, Oregon.

    Like 3
  8. local_sheriff

    Hey, yet another cool device to effectively help kill yourself in the traffic !

    Though I’ve held a motorcycle license for a mere 20years and do ride occasionally, I still regard my skills as rather basic. Maybe that’s a good thing.What I have learned though is that the biggest asset with a motorcycle is the possibility of leaning/shifting balance to effectively tackle bends. That property is lost on a trike, making you end up with all the cons of a motorcycle but none of the pros!

    The Tri-Magnum company / Robert Q Riley site has a cool clip of the prototype appearantly shot in the very early 80s showing interesting street scenes

    Like 1
    • Howard A Member

      Well, hold on, judging by your name, you are involved in law enforcement, and I thank you for that, but you people see the worst of the worst, and not everybody kills themselves in traffic on this stuff, you only see the ones that do. Fact is, many folks put millions of safe miles, you just don’t hear about them. My biggest problem with a 3 wheeler, is that single wheel always rides in the “oil strip”, as a motorcycle rider for over 50 years, I’ve seen some wild stuff in the oil strip, from bolts, to gun bullets to driveshafts, the stuff 4 wheelers don’t hit. Also, another big plus of 3 wheelers, it allows folks that can no longer ride a motorcycle, to enjoy riding. That’s the biggest plus of all, and 99% make it home ok.

      Like 11
      • local_sheriff

        I fully agree with all of your points Howard, and 50 years riding is an impressive career indeed!
        Just to make myself clear; I do enjoy riding a motorbike as it’s a very different, more direct experience than a car. Point is, most 2wheeler properties are lost once you get up on a trike or ATV at highway speeds, still being just as exposed as on a bike.
        Most motorbikes, Japanese and Italian ‘angle grinders’ in particular, have capapilities way above the level of those riding them. Bad stuff happens when riders start thinking they are just as good as their bikes.
        Ride defensively and enjoy the open air adventure!

        Like 6
      • Terry R Melvin

        Spoken by people who don’t ride trikes. I do, and none of my wheels are in the oil strip. And they don’t tip at all unless your head is really where the sun don’t shine when you’re riding.

        Like 1
  9. Kenneth Carney

    You might be onto something there Shawn. Other than motor and battery
    placement, it would be a very cool way
    to commute to work each day. Wouldn’t
    be a long distance driver by any means,
    but a really cool ride nonetheless.

    Like 2
  10. Brian Snyder

    I admire anyone who got this far on the build of any of Robert Q. Riley’s plans. I was in high school when the Popular Mechanics article came out on the Tri-Magnum. I saved my meager part time earnings to send away for the plans. I still have the magazine, I still have the plans, I do not have a Tri-Magnum. I’m a good carpenter, and can turn house plans into reality, but never had the confidence to start on my Tri-Magnum plans. I guess the only way I’ll have one is to buy this, or one like it, and appreciate that other people have greater talent or greater gumption for creating mechanical things. I wonder if I could get this across the border under Canada’s 15 year importation rule?

    Like 4
    • rod444

      I was going to say, “not likely” but I think this would qualify as a motor tricycle. At the bottom of the page for Motorcycles on the RIV site’s admissibility chart it does say “All other motorcycle, motor tricycles, scooters or mopeds not shown as admissible on this list are inadmissible unless not regulated at importation due to age (older than 15 years).”

      So as long as you can prove it’s older than 15 years, it might actually pass.

      My experience with importing at the border is that it depends whether you catch a border agent on a good day or a bad day cause the answers you get seem to depend on who you talk to and how polite you are :)

      Like 1
      • Brian Snyder

        Thanks for the info rod444. I agree with you that these things are often about how you deal with the individual, not about how you can interpret the rules of an organization. If I could get it across the border, I also have hope that I could get it on the road with Ontario’s current pilot project that allows 3 wheelers like the T-Rex or the Polaris Slingshot to be licensed and insured as motorcycles.

        Like 1
  11. Doug

    The often overlooked problem with 3 wheelers ( other than sidecar rigs ) is that if their is a pothole, brick, or some other hazard in your lane, the odds are extremely high that at least one tire will almost certainly hit it, where with a 4 wheeled vehicle, one can often straddle the hazard, avoiding any contact.

    Like 3
  12. Maestro1

    I had a chance to buy a three wheeler from a Police Department in Central California, used for parking meter patrol, in excellent mechanical condition but terrible appearance. I know nothing about motorcycles but I have friends who do, and I took two for them with diverse opinions with me when I went to see the bike.
    I passed on it because I had no skills. I still don’t. Life has interfered. But I remember certainly wanting it. Salud to Howard A and his experience.

    Like 4
  13. rod444

    Hey Scotty, as for fitting someone tall under that steering wheel, looks like on the video that the steering wheel swings up for uh, loading. Between that and possibly replacing it with a removable wheel, even us lanky types should fit. Course with a seat that’s more like a hammock sling, I’d be far more worried about getting OUT of a Tri-Magnum with anything that resembles dignity.

    Here’s the site for the Tri-Magnum and many other cool ideas for those who are still looking for projects to add to your collection:

    Like 3
  14. John

    Just saw one of these for sale on Facebook Marketplace – complete with A/C!! I have an ’83 Interstate in my shed with 39K on the clock and wouldn’t mind using it as a donor.

  15. Ron Rif

    Brian. I purchased a 1972 Beetle to use to build a Tri Magnum, after many years of drooling over the idea. I would very much like to purchase your plans, or would pay for a photocopy of same. Pls email me asap at to Discuss!!

  16. Stormstopper

    An even earlier design found in Popular Mechanics in the ’60s was called the “Scarab”.

  17. Brad Rice

    Came across one a year ago, wasn’t in best shape, slowly getting back to paint , runs great , 1977 750 Suzuki. As said going for new electronic ignition instead of points, original motor is great running. Looking forward to finishing, I’m going to post few pics, big question what Color would you paint it?

    Like 1
    • DayDreamBeliever DayDreamBeliever

      Something BRIGHT!

      Thinking a loud color of yellow, maybe. So low, you wouldn’t want to be missed by today’s distracted drivers.

      Like 1
  18. James

    I own a tri magnum, still trying to figure it out but it’s beyond its time and looks alot like something in a blade runner movie

    Like 1

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