Q&A with Torsten Hallman Part 1: Hi Torsten, Any information you can share about the bike would be greatly appreciated by us and our audience. Here are some questions we have; 1.) Where did the idea for the project originate? Did you always believe that 4-Stroke engines could be affective again for motocross racing? As an importer of Yamaha motorcycles in Sweden, we received early information about all new products. We got specifications, pictures etc of the engine of the new 1-cylinder 500 cc engine that would be sold only in America with the model designations TT500. We immediately contacted Yamaha to order some machines, but unfortunately, we were turned down. The answer was, the model is only intended for the US market. We then tried to buy only one or more spare engines - but were turned down. Why such great interest on our part? In the first place, it was Sten "Storken" Lundin, who was the biggest 4-stroke enthusiast of all of us at our company Hallman & Eneqvist Motor AB. Sten was the service manager at the company. He studied the specifications, pictures, etc. carefully and was convinced that here Yamaha had designed an engine that would be suitable for motocross - if you could reduce the weight and increase the power of course. Sten was one of the forerunners in Swedish motocross when the Swedish riders dominated the World Championship motocross in the 50's and 60's with Swedish-built Albin 4-stroke engines. The Albin engine was originally intended to be used for military use but was perfectly suited to be rebuilt into a high-performance engine. Most of the engines that were adapted for motocross, were built and tuned by Nils Hedlund. He was also the one who prepared the engines on the Husqvarna factory's 4-stroke engines. It was with such an engine that Sten became 500cc world champion in both 1959 and 1961. So, the idea came from the original idea of Sten. But both myself and my partner in the company, Staffan Eneqvist, were just as enthusiastic about the idea. We were convinced that with the right rider and a more modern 4-stroke engine, they would be competitive. We then decided to start the project and see if we could make a competitive motocross bike. From the beginning, we hadn't even thought about entering a team of our own in the World Championship series. That idea came later after Bengt Åberg got to test ride the first HL prototype. In retrospect, you might think it was a "shoot in the dark"! 2.) Is it true that Yamaha didn't want to send you an engine that you would use for the project? And that you managed to track one down and purchase one on ISDT at the Isle of Mann? As I mentioned in the introduction, they did not want to send motorcycle models or engines that, at that time, were not planned to be marketed in Europe. However, we were lucky when my partner in Torsten Hallman Racing Inc. in La mesa California (later THOR) - Lars Larsson, was visiting Sweden to prepare to ride the ISDT on the Isle of Man. I had talked to Lars about how we had failed to get a TT500 bike/motor to Sweden. When Lars came to the Six-Days, he met an American who was going to participate with a TT500. Lars then calls me and tells me about this. Right away I said, Lars - Buy it right now! Make sure it comes to Sweden when he's done with the race! 3.) How long did it take to go from conception to a GP-ready machine? We got the TT500 in the fall of 1976 after ISDT - and had the new HL500 ready for the start of the 1977 World Championship. First, the engine was dismantled down to the smallest detail by Sten. He saw what had to be done. He changed and lightened several details, mounted American tuning parts that were available for purchase from White Bros. in the US and then mounted the engine in a Husqvarna frame to be able to test ride the engine. We contacted Bengt to come and test the prototype. He tested and thought we were on the right track. We then contacted the frame builder, Profab in California and shipped the frame that Sten had welded to suite the Yamaha engine and asked them to build a frame plus aluminum swingarm according to our drawings and the frame we sent. After that, the hunt continued to lighten the whole bike, with aluminum shafts and titanium, plus we also used lightweight FOX Airshox. When it was finished, it weighed 104 kg. Unfortunately, Sten later had to change more parts to steel - after Bengt tested the machine in World Championship race pace.

I saw Bengt Aberg on the original HL500 at the Puyallup Trans Ama in the mid '70s. The second moto was a mud-fest, and Bengt took the start against the fastest open class 2 strokes ever, eventually finishing behind Arne Kring. It totally blew my mind, and left me with a life long smile, and obsession for thumpers, which continues today. Another great video, Max! Thanks.

I remember an article in MXA during the mid 1980s where Rick Johnson tried the HL500 and declared it the ultimate motocross bike!

This video brings back memories, thank you! Bought a brand new XT500 in 1976, after this bought a HL500 and did club competition locally. Then bought a Rickman 500, it had a full aluminium frame, hand welded. Guess only few were made. Another MX clubmember had an CCM which I never could keep up with.. we raced in a field of 2 strokes, but mostly finished somewhere in the front pack. The motor pulled everywhere, got a nasty crash and that was the end of my few years in MX competition. Bought new RD350LC and RD500LC... and tuned the crap out of these. Always Lectron carbs. Kept the XT500 for many years and was offered a brand new XT500 if I traded in my 76 model.. It was one of the very first XT500 and I kept it original. But I declined the offer... wish I never sold the HL and the Rickman ! Hey I survived it all .. Lost many friends... still have some photos of the Rickman. Time sure flies! Thank you !

Nils was a true craftsman. And I'd listen to the old timer any day!

Good review, Torsten is right, these bikes were easy to replicate as a lot of the parts are standard Yamaha issue, forks, wheels, tank etc. I made my first replica back in 2000 and have made nearly 100, I'm also amazed that the enthusiasm for them is still there. Cheers, GMC

A fascinating history lesson. I think Yamaha XT500 rings a bell among many motorbike enthusiasts but the whole background story with those Swedish guys adds an whole other story previously unknown to me. TnX!

I think Alan Clews and John Banks would like a word , They were out there in 75/76, I raced against one of these HL-500's ( from the Gloucester Club I think) in the early 80's aboard My 79 580 CCM, As 4 stroke riders in that time We had our own friendship, The riders Dad did the sound Meter so no problems with open pipes 😉, later I had Vic Allen's Mitsui TT-600 Haynes Championship bike, They still had a weak 3rd gear, That used to overheat and loose its Hardness, Mitsui had a university look into all the available oils And running Shell Rimula X diesel Oil was the only one that solved this problem 👍, nice video

I had an HL500, bought new in 79 from Bates in Dartford, Kent. God I loved that bike, got a 4th at Canada Hights and a 3rd at Slade Green. Wish I never sold it.

Another maker of special 4 stroke motocross bikes ,that it would be interesting to know more about ,is Kelvin Franks , an Australian who was based in southern California,. He , like Hallman and Lundin ,was into making competitive 4 strokes, when 2 strokes were the thing to have. An example of his bikes was a C&J frame , with CR components, and a hot XR500 motor , ridden by Jeff Jennings, a beautiful bike.

The two stroke can never be killed as it will always live in the minds of men. Men who are not afraid to hold it wide open and go BRRAAAAAAPPPPP!!!!!!!!

I remember those days back when Roger DeCoster won five 250cc world championships in a row, he was an amazing rider. and I also remember Montesa having a pretty decent motorcycle in motocross racing with Mikkola Anderson. I was a huge fan of Montesa motorcycles I thought they were the coolest looking bikes ever made? I remember there were full page ads in the motorcycle magazines of all their models. that were each size of the Cappra models, which were their motocross and enduro models. and each size of their Cota models which were their trials models. which by the way Montesa was dominating trials events during that period in time. the ads were a full page showing a picture of their bikes with a brief description of the bikes. it was a unique advertising campaign. I used to stick the ads on the wall and look at them. I wanted a Montesa really bad but they were difficult to find in the United States, dealers were few and far between. so I got a Husqvarna instead. I thought Montesa had gone out of business many years ago? but as recently as 2023 I have found out that Montesa and Honda have had a collaboration on a trials bike. for over ten years quite a surprise indeed. I remember the Yamaha HL 500 and thinking back then a four stroke thumper probably wouldn't do well on the motocross track. but was surprised when I would find out that they were doing better than I expected. I even thought if they keep this up they would build a four stroke that can be successfully raced in motocross? and eventually Yamaha did just that. I don't know why but the bikes in this video look so much better than I remembered back then? the one's in this video look fantastic and I bet they are probably they are great to ride with their forever wide powerband? it seems like Yamaha is more willing to experiment with four strokes in more applications than other manufacturers? some years ago it was either coincidence or they saw the writing on the wall. when Yellowstone Park decided to ban all two stroke snowmobiles. so Yamaha decided to produce the R1 snowmobile. which uses a modified four stroke engine from the R1 sreet bike. which was met with mixed reviews. but if that's the direction the industry is heading many people thought it would be a suitable snowmobile?

Very cool Hallman/ Aberg. The brand CCM might be the first “two stroke” killer. Technically. The Yamaha was way lore advanced and competitive though.

Im a two-stroke bloke all day long, BUT those HL 500s are beautiful machines to behold & that sound..... . Great history lesson . Fantastic that you got Mr Hallman to confirm some of the mystery surrounding the HL . Bengt Aberg's contribution should not be overlooked ( not suggesting you did )- a brilliant rider . Thanks for a ripper episode.

doing my racing in the late 60's, early 70's, it's cool to see videos of the history back then that I didn't know about. great job. 👍

I had a 78 xt500. It was a bulky machine and difficult to trail ride. Power was decent. Best on fire roads. The HL500 is a beautiful machine. Those bike need put into a time capsule. On YT Brad Lackey is racing head to head with a Maico 490 Mega 2. It's a vintage race. Outstanding how you all do it on this channel. Hats off once again!

Thanks Max, a quality and fascinating episode. Great to see and hear the great Torsten Hallman, a legend when and where I grew up in SoCal in the 60's and 70's. I had a pair of his leather motocross pants and was rightly proud of them.

This is a hell of a post!! This is something that person as I born around that time,would have never known! Great Job!! Thank you !!

Dont forget the CCM ! If it had been allowed into the 250 class together with the HL Motocross history would have taken a completely different course.

The test ridden bike had an SR500 motor with bigger valves and electronic ignition.. which was a better platform than the older TT motor. The bike Bengt Aberg rode also usually had a wilder cam, two gears removed and lighter flywheel/ignition, quite a different beast to the stock motor…hence the alleged 50hp.

I had an early XT 500 in 1976. Loved that bike. Even rode it in an enduro. Only once, it was too heavy really, but good fun. Amusing anecdote, I was on my way to work one morning when I was pulled up by a police motorcyclist. Nothing illegal , he just wanted to see my bike as he hadn't seen one before. Good job on the documentary.

In early 1979 my late brother Peter Stayt imported a Bendt Aberg replica frame from USA to Australia and took an engine out of a TT 500 and won the Finke Desert race. I have one photo of it. i got to ride it once. It was sold to a guy and ended up in Adelaide to my best knowledge. I've seen one HL 500 in my life. It turned up at a vintage meeting near Boonah Qld. Never knew they existed as such. An interesting story that filled a few gaps. Though really for my money, the most revolutionary bike ever made was the very affordable DT1 Yamaha, that allowed the masses to turn up and race or trail ride or whatever. I had one in the 70s I raced and did all manner of club events and rode in to work during the week

That's the oldest four stroke you've ridden? You need to do an episode about the Rickman brothers and the magnificent Rickman Metisse mx bikes. There are two books describing the amazing history of their world changing machines. The Rickman Story, and The Metisse Story (a re-write) both books by David Gittins. 1965 was an amazing year for mx. They saw that the two strokes were going to make four strokes obsolete so they proposed that a four stroke class would make an excellent addition to the FIM world championship. As always, politics shot that down before it had a chance to grow.

I saw Bengt riding the Hallman 500 during the 'Trans-AMA' series @ Redbud in 76-77. He did quite well since it was a mud race in October. You always heard it coming among all of the 500 2-strokes.

I had a hotted up tt500. Loved it so much. Brilliant bike

Thank you for another fun and interesting video. There are so many twists and turns to the story of motocross that it makes my head spin. And when you consider the motorcycle industry as a whole, it is mind boggling. But thanks to knowledgeable people like yourself we can hear about certain "chapters" of the story (And don't get me started about Harley Davidson. Lol.) Personally I prefer 4 strokes. They just sound more civilized than those buzzing 2 strokes, but there can be exceptions. I have owned several small 90 and 100cc bikes over the years. This is what happened in the early 70s. My favourite was my Honda S90 because that candy red paint job was a chick magnet ("Can you give me a ride home?" That's how I met my wife, but that's another story :-) It was great for zipping around town doing errands, going to work, gawking at girls, etc. My 2nd favourite was my Yamaha 100 L5TA (2 stroke :-) because it's rotary valve engine gave it tons of low end torque (for a 100 :-) and the low first gear meant it could climb any hill until it flipped over backwards if you're not careful. It's low seat height meant that your feet could always reach the ground. Even though it had a top speed of only about 45mph it could beat most other dirt bikes in tight, twisty and muddy trails. My friend had a Suzuki RM125 and he was always saying "wait up" in the rough stuff, but he would leave me in the dust as soon as we were out of the woods and onto the flat stuff. Anyway, I just thought I would tell you a little story from personal experience as a thank you. PS - Here's what happens when you have the latest superbike. 🏍 🚓 🚓 🚓 "Pull over.. Now!!" Cheers from Canada.

Hi from Texas, Great Video. I’d never heard of the mHL500 Story. Hats off to them for taking on the Big Companies to produce a capable and Winning 4 Stroke. Incredible Work by this Team. I really enjoyed the Video and the Story, Thanks for making it.😁👍👍

Max your channel content just kicks ass !

This is a superb vlog Max, you n Dave have raised the level again with this old school MX story… great details that might be lost in the coming years are now on record ❤

I remember watching them in the 80’s they sounded fantastic. AMCA 4Stroke championships. 😊

Bought an XT 500 new in 1978 along with a few mates great bike, sold it when the IT 465 came out dailyed both cheers for the memories.

Nice thumper !! Had a 81 dr 500 I was 18/19 maybe 145 pounds. It was a low end power machine. Top speed ..75or so. Glad to see the fun ride ! Enjoy.

Great episode & on bike commentary on a legend of a bike. As always a great job by you and your team Max👏👏👍

In 1978 I was 18 and had a TL 250 thumper trials bike and bought the second year TT500, polished tank orange top it was beautiful, and I learned how to shift gears on a wheelie. Even with a clutch, which was how I always rode then. I could go for blocks. I had a blast and I was amazed when I put a single K and N eliminating the airbox. I really had to bump up the jets a lot and the torque and response was huge. It was heavy but it worked pretty good, thick torque that would blow the tire off anytime you wanted. I've been a thumper guy since. Good memories

A fantastic and interesting video Max, Thorsten and co pioneered that bike and probably their design had a hand in Yamaha's return to four stroke MX bikes, well done Max.

Great vid especially since I lusted for the XT500 as a schoolboy in the 70’s, and the HL was another level again!

My friends Dad had a mint XT500 I think it was a 78'? We rode it as kid's, 14&16yrs old in the mid 90's! That 500 was a leg breaker to start, even with the decompression lever.. Heavy bike but the power was bottomless! I had it to 90mph multiple times! No helmet, sneakers and shorts in the summer time! 😂

You've been putting out some great stuff. Thank you and keep 'em coming! 👍

Great Vlogg max , love to see the old bikes

Great vid Max, I have a '77 TT500, it's a bit of a pudding but the lumps a stonker and I love it. Great to see vids on rare / unique bikes.

Wow! What an awesome story!! Fantastic that you got to ride one as well. Thanks for making a great vid man 👍😎

Great video. I owned an XT 500 back in the day and rode a replica a few times in the 1980's but I definitely preferred my "81 YZ-465. In fact, I still have it.

great information about this classic motorbike

So good to see this bike featured, 2 strokes are undoubtly what i love to see, and apart from a daliance with an early 600 Husaberg in the mid 90s that is all i have known. But that all said, if i could have any classic MX bike the HL500 would be it! it just looks so right....Great video as always!!

I never thought I’d stick it through all of the video, but this was great. Well done Max for putting it together. It was a great insight 👍

Max, This was a great telling of the development of legendary HL 500! Thank you!

Excellent job on video!!! 💪💪💪💪

As a 2000’s kid. I thought the original “2 stroke killer “ was the WR400F, it’s cool that Yamaha was doing it for a whole while longer

Great video Max, brilliant story telling👌👌

So I'm bullox deep in, I think, a very interesting and unique build. I've had a 2003 yz450f since it was new. I have a 2020 yz250 2 stroke and a 2024 yz450 as well. Anyway a few years ago I bought a 2004 wr450 for the 5 speed gearbox. The 4 speed wasn't cutting it in the dunes and that's all my '03 is. She's a black and purple dune queen and she's wicked badass. So I've had this wr450 rolling chassis in perfect condition just collecting dust in my shop. Well, I ended up acquiring a MINTY FRESH 2003 xr650R from a Buddy of mine. I traded him a 318i rolling chassis with a 6 point cage, wisefab front control arms and extended tie rods, maxpeedingrods coilovers. It literally has nothing else not even a dash. So, because i m a big dumb idiot, I blew apart a perfect xr650, and stuffed that air cooled powerhouse in the wr450 frame. I'm an automotive fabricator/mechanic by trade so, it was actually pretty simple. I got the engine in the frame, got everything perfectly straight and rolling perfect, tore it down and sent everything out for powder coating and sent my forks and shock off to enzo to get all dialed in for the new powerplant. I only rode it on the street but...dude.....DUDE!!! THE THING IS ABSOLUTELY NUTS!!!!!! If you're ever in Nevada, you gotta hit me up and do an episode on this thing. Its indescribable the way it feels. I'm putting a big cam in the engine, valve springs, shaved the head a few thou as well as ported and polished it, hinson clutch and basket, I'm building my own exhaust that goes 2 into 1 into a stock cr250f dual muffler setup I've had laying around for like 6 years. The whole point of the bike is something I can ride to work that doesnt do 112mph in 1st gear like my R1m. I'm gonna eventually do a fuel injection setup and a small turbo. That's the plan anyway. I'll keep you posted buddy. Keep up the good work!!!!

Thank you very much for that well deserved HL special 🙏 May I ad that, between the HL and the YZF, there was Husaberg !

This is an awesome episode!! Thank you 😊

I love two-strokes but you've got to admit tracktability wise four-strokes find the grip really well 👍

A great episode, really interesting,and amazing research... And what a beautiful bike..👍

.. Another most splendid vid,.. Nice one, Max ,.. 👍👍👍

Max , i really am enjoying these videos on the older bikes .

Still waiting for you to do CCM please 👍

Its absolutely mind blowing they got that bike down to 225lbs in that time.

Another Bobby Dazzler video 🤠🇬🇧🤟🔥

The XT/SR motor just looks right.

As usual, great story Max. This is the bike that proved that 4 strokes were NOT competitive and why Yamaha and other Japanese manufacturers (unfortunately) convinced the sports controlling bodies to allow the doubling of capacity to make racing 4 strokes "fair" and supposedly on equal terms. The marketing and environmental aspects dictated the direction of the sport and I believe were not in the best interests of genuine development by competition.

Sold my overweight KLR 650 and ride my like new 45 year old XT500 now.😊

I want you to know that back then MXA, ( Motocross Action Magazine), did write about all those great Euro riders as much as they could, (probably don't now. The rag sickens me today, so bad), because I grew up reading about every one you mentioned, even before USA riders took over. :)

What an absolutely wonderful video and vision of this historic mx bike , I was so in tune with this I've watched it twice 👍 truly a vital piece of history in our great sport 😀 you can almost feel what it must have been to race it 🏁

Excellent video! What a great story to tell, and 999lazer did a great job with another rare motocross specimen. IMHO, affordable 4 strokes became competitive for dirt bikes only after technology had evolved enough to make a very high revving engine which was durable enough to sell.

Max, a story on the Hagon 500 yam would be interesting. Probably the first aluminium framed bike. I think Martin Hagon even raced a sidecar based on the same principle in later on.

Love this episode! I am in process of rebuilding a 1983 TT600 currently and the history/lineage you cover here are top notch. Im obsessed with the 851-888 Ducati road bikes and would love to see an episode on the Cagiva WMX series bikes if you find some time. Keep up the good work!!

Superb jobb. Much appreciated

I raced a Hallman 500 for about 3 years. A friend also had one punched out to 600. They were good hole shot kings, after that they were too heavy to hold off the 2stroks. I would start in 3rd gear! I only won races in the snow or mud.

Hey op mate totally blown away by this video never heard of HL500 before, in the second half ov 80s fitted a XT 500 motor in husqavana cr 250 (83 or 84 model) wasn't that hard really after engine plates were made up, used the 38 mikuni from the husky with a jet kit from some place in oz ( which worked perfectly) and took bike to exh mob just south ov Sydney for a stainless one to be made, bike worked out nice but did feel a bit heavy on front end, raced it enduros a couple ov times

Story could easily be made into a movie!…sort of like “Ford vs. Ferrari”. Great job!

This was the catalyst undoubtedly, and the Suzuki DR 400 that MXA made was another 4 stroke that had me dreaming about racing one way back in the early '80s. Such a turn of the worm how the 4-stroke had such a soulful sound back then and now the sound of a two-stroke brings out similar emotions!

42mins of pure pleasure...just a shame about the small track. As for how good they're to ride is pretty much horses for courses, for me she did everything I wanted. Look forward to seeing her on a bigger track.

Epic bike. Legend. Wonderful story. A parade of Swedish Champs too. Many thanks for this video. Keep your boots dirty.

Great video

Bengt Aberg my favorite rider when I was a kid. The "Berm Master" I remember the titanuim framed works Huskys in 72 during the trans ama series. He also rode for Bultaco in 74/75....R.I.P Bengt

Interesting thought experiment!

Those also made a great flat track bike my brother raced,using a champion frame,

Back in the day I loved the 500 Yamaha and owned a few. I always wanted an HL500 as it seemed rather like the Holy Grail for 500 Yamaha fans. Many years later I got to own one and race it in vintage MX. The bike I bought was a ProFab kit bike assembled in Australia by the design guy for a well-known local motorcycle publication. I rode and raced it for several years, but as a decidedly average racer I found it less than impressive. Perhaps it was the suspension used - RM400 forks with a set of S&W shocks - but it was a pretty rough ride. I enjoyed it of course, how can you not, but I think that by 2004 I'd had enough experience of other bikes to know it wasn't quite what I'd imagined. I later traded it on a new-build Husky CR500 on which I had much more racing enjoyment. I do kinda wish I'd never sold the HL, however. PS: Super interesting video, thanks heaps.

Great story and interview with the man who built it

Thanks for the great story there was a lot of good info that I never knew anything about I have been a yamaha fan my whole life 1st bike was yz50 then moved onto yz125g then later a yz250k then tt600 98 model then wr450 2003 model and now I have a wr450 2016 👍

Great Story Max good on You cheers Mick Australia

Well done max and team!

Great history lesson

That looks surprisingly modern

Wow! Awesome video!

The XT500 and the TT500 turned up in Australia as well. I remember some being shoehorned into a Honda CR500 rolling chassis for better handling.

I rode a 1977 TT500 back in the day. I ways felt my 1980 XR500 had more top speed and was a better trail bike overall. Cool history lesson!

I can't imagine any mx bikes from the last ten years or more standing the test of time like the bikes from the 70's and early eighties. I always found the racing much more interesting when there was a two stroke/four stroke battle going on. So many people mention how good the CCM's were. But all I remember of them is the countless breakdowns. My first exposure was Norman Barrow flying over the girling leap and booming off up the hill at Hawkstone, chasing a couple of rm370's. It was shaping up to be a great race. But of course, his bike packed up. I had just turned 7, but the memory stuck with me.

Damn I am glad I found this video, I had 3 of the TT500's back in the day, a 1976 a 1978 and a 1979 that was completely built up like the racing HL's feature here (very closely anyhow) it was also HEAVILY modified in the engine with a complete White brothers racing preped head and stage 3 cam, white brothers big bore stroker bottom end (605cc's actual) and white brothers race prepped gear box, 44mm mikuni square slide carb, simmons upside down forks and tripple clamp, the frame and swing arm same mods as on these bikes, then things like the air box was replaced by just a UNI pod air filter the metal gas tank replace with a plastic ( can not remember exactly where it came from but it was an aftermarket one made for the bike) and everything not completely vital to the bikes function was stripped to lighten the bike, that bike was INSANE on power and handling and suspension was on par with some of the newer bikes today, also had a 1979 XT500 that I rode back and forth to highschool every day I could (1984 graduate), I had all these bike from about 1981 to about 1986 time frame before moving on to the TT600's, OHHH how I wish I still had those old wonderfull TT500's even the 2 bone stock ones were such a good and dependable trail bike you just couldn't kill them no matter how hard you tried, I had submerged them in rivers more than once, pump out the water fire them up and keep on riding, even punched a quarter inch hole in the engine main case on the 1976 while 18 miles out in the middle of nowhere in the rock mountains of Idaho where I live, and thanks to the dry sump type of oil system those bikes have was able ride all of those 18 miles without running out all the oil in it to get me home, I fixed it by plugging it with one of those expanding foam ear plugs stuffed into the hole and rode it just over a month like that before I tore it down to actually fix it, it was that same bike that on 3 seperate occassions while racing someone I missed a shift over reved it and bent the exaust valve, and 3 times it still got me home that way, and 3 times it was fixed by hammering the valve on the high side of the bend into the valve seat to mostly straiten it then lap the living crap out of it, stuff it back together with the SAME head gasket and high temp silicon as cylinder base gasket, fire it up and the damn thing always ran like new again, it wasn't until it did it a 4th time that I put a new set of valves and valve springs and fixed it more proper that way, and the white brother high pressure springs that kept it from bending the valves again, that bike and the other ones had the living guts rode out of them when I had them, and every one of them ran like a top when I got rid of them with never doing more than things like oil changes, tires, airfilters and basic maintainence stuff, never a single issue or problem with those bikes, GOD I miss those bikes because todays crap is just too delicate anymore they just can't take the pounding like those old TT's could not even close.

That bike sounds so sick

So glad you managed to find one of these things, I mentioned you should seek one out in your story on the gilera twin cylinder. One of the big things with the HL is no two are the same so set up is critical and its not surprising the production bikes were a dissapointment to the owners. I noticed on the survivor bike your friend has that the drive chain is laying heavily across the swingarm pivot and the swingarm is noticeably shorter than the photos of the bike bengt was riding, willing to bet that your friends survivor bike handles horribly in the form its in at the moment. Dosent stop me from wanting it badly though as im sure it could be sorted!.

BSA did try something similar to the HL500 , they produced a 500 Goldstar based on the 250 single bike in 1971 . Unfortunately the company was already on the skids .

Fascinating! I would like to see a video and what you make of the VOR/Vertemati story. I think this was a suppressed marque, especially in the American context, due to the results it was producing in the early 90s. Check out Mika Ahola in the VOR context too. I am lucky enough to own and race one. There are still many alive and being ridden all over the world.

According to all the videos I've seen on the hl 500 mine was one of the nicest ones ever made. I lived in Santa Fe New Mexico at the time. It was built-in Las Cruces, New Mexico at the Yamaha shop built for desert racing. It was geared to go one hundred and ten miles an hour.

At 11m48 seconds and you haven't mentioned a thing about the unique head--a 3 valve ..Designed and cast and finished out on the east Side of Metro Stockholm---not far from Hallman-Eneqvist, the Yamaha importer and part of the Eneqvist Volvo dealer gang....Cams by Nisse hedlund--also out on "the East Side"....My local Husky shop had been Team Eneqvist...run by ex-GP mechanics the Moberg brothers... Fortunately right there at 11m46-48seconds you see in the caption in the magazine the mention of the 3 valve head... That head was a big part of why the engine made power enough to keep up with 500 class 2 strokes which were between 354cc or 384cc (Husqvarna and KTM) and 440cc.. The bike was cool of course but at Easter Trophy in France April 1977 I was on the start line with Åberg and 35 other top guys,,I was on a bog standard 400 Maico..Only second 500 International for me. Start straight at Château du Loir was about 330m long, good wide left first turn..I beat Åberg on the start..Didn't last many laps before he absolutely blew by at the end of lap 2 at the end of the start straight.. My point? Whatever the bike did, it was Bengt Åberg that made it do whatever it did.. Vila i fred, Bengan.

Great video but I love two strokes!

My hl500 Had kyb factory suspension dual high volume oil lines to both cam followers and a oil cooler in the air box. With a lectron carb. Piston sr head .

Great job max

Loved my XT 500 and always hankered after one of these 👍🏻