"The audience is now deaf" But really, congrats! Thats a big achievement.

Fantastic! The noise, the flames, the smoke, the vibrations. Absolutely brilliant!

So exciting! It will be fun to see when all the little bugs get worked out, a permanent starter is figured out and the first road test ride!! Loving the videos, great job to all involved!!

Such a beautiful piece of engineering. Im here from Facebook! Saw a short of you starting the bike. Saw how simple yet complex your engine design was, and became instantly intrigued. Glad you finally have it started!

and the flames came out of the right port too! 😁

Tremors felt down here in Aus.! I note that the chain has already surrendered to the impending massive torque load. Congrats and well done.

Absolutely magnificent! Ive been excited for this day to come and now im even more excited to see it running and hopefully going on the road sometime! Great work and enjoy ur drinks!

That Giant Piston would act like a Wacker Packer! The Vibration would be Crazy - Cool None the Less

Niiiccee!!! Earth shattering machine!!! You can be really proud!!!!

Yay it lives! Nice work! Cheers from Canada!

Well done guy's great work by you all, very special moment.

Congratulations. Well done!

Last week, me and a bloke put to together a Vulcan 400 with straight pipes.the noise in the shed when we started it was deafening. But now i saw this beast, id say it was rather quiet...😂😂😂 Great job there!

Congratulations 🎉I've been following your build from the beginning and this is an absolute milestone

Congratulations, been looking forward to forward to this😊

Very nice, great success, been waiting for this day since discouvering your chanel, but watch out for the decompresser, cause you can see it beeing succed in in the video.

It's only when you got on it I could see just how big that cylinder is! 😊

Its sounds incredible!! Congrats!!

What an achievement. A unique bike with a special engine. Well done to all the team:-)

Great work chap... Massive milestone..

Congratulations to the success.

Brilliant! I've been following this for a while. Amazing achievement with such an ingenious ,unusual bit of engineering history . Enjoy the pint!

Absolutely, bloody fantastic.

Thunderous! Congrats!!

Congratulations, Mark and team!! What a great sound.

Congratulations from the Netherlands!

Awesome, love to see this and the project! It sounds snappy and awesome for a huge single cylinder! Congratulations.

Привет из России. Шикарный проект. Урчит как котёнок

Amazing to finally see it run! Well done sir, congratulations on your success. Soon it will be cruising down the road with a very happy man in the seat. 🖖

even the camera got excited 😂

As a biker, I'm curious. As an engineer, I'm fascinated. First time this has appeared in my feed, I have some catching up to do 🫡

Hahahahah.....fkkin brilliant!! Another Hercules cylinder breathes life again!! Only 13 more to go to make a complete engine....WELL DONE!!!

Massive achievement, looking forward to seeing you getting all the variables zeroed into the optimal set up. What a beast 💥👏

Congrats! Hopefully you'll be able to get the starter situation solved without resorting to dropping compression further. Also, I wonder if you need a stronger spring on the compression relief? It seems like it may have been getting sucked open a bit on the intake stroke whenever you closed the throttle.

Mate...that is...on another level. Congrats ❤🎉

Wow. Hats off to you guys. Bad ass.

Congratulations that thing sounds rowdy!

Incredible, well done!

So chuffed for you Mark!

Well done👍👍 Cheers from California.

Bloody brilliant! I was starting to despair!😄

Epic! Clear prop! Chain in this case! Congrats!

Wow! 🎉congratulations dude! It sounds INCREDIBLE!

Well done Mark and the crew. 🎉 Great achievement! Sounds a bit like an old two stroke 😝 just now but I’m sure it will be purring in no time. Like I say, brilliant results and very inspiring. See you on the road real soon bud 👏🤘

Need new fillings after every ride 😂 awesome!

I love the way EEEEEVERYTHING shakes, well done guys I’m going to watch more!😊

Sounds mental,,congratulations

I thought my KTM 500 vibrated until I saw this beat fire up!

Awesome job, boys!! From the left side of the pond👍😎

Epic!... congratulations to you and Bob!

Wow that thing is a beast! Very cool.

Love that it uses half the fork stroke when starting up 😂😂

Well done lads!!!

Woop woop it's alive 👏🏻congratulations to all, just brilliant 👍🏻🇮🇪

Many years ago a old man told me about a single cylinder truck in Germany . This soon after the war . Said it was chugging up a hill carrying a load of wood .

Awesome! I just caught up on watching the whole series. When you said £300 for the aluminium to build the new head I nearly sh8t myself. I was shouting "Make one out of something cheap to check if the starter can beat the compression." Of course, you have done it now, but I have piece of nylon if you want it. About a foot across and eight inches thick. Fnaar fnaar. I drive all over the place, frequently near Derby, not a huge problem to get it nearer. (I can't fit in on my lathe and want it to go to a good home.) I will be watching future episodes, just say if you want it, I'm known as Grog.

Well done! 😎

Awesome! Sounds amazing. Well done guys 👍

This is the first I've seen of this thing. Instant sub. I'm gonna spend Sunday binging to catch up , everyone leave me alone today please.😁

So great, I just sit here with a big grin on my face, enjoying your succes. I´ll drink to that! ;o)

Very well done. Excellent !

Some seventy years ago -late 1950's / early 1960's I was working in the ERD [ Engine Research Dept ] Patchway works of the then Bristol Aero Engines Limited. We used to run single cylinder sleve valve test engines. Hercules or Centaurus size pots, they ran as far as I can recall with a heavy flywheel. I think this motorcycle application may have had a crankcase etc from one of these units. A sleeve valve crank mechanism would have to be involved. I reckon it would jump up and down a bit without a well balanced crankshaft and maybe a flywheel as well. We ran many separate parts of the whole engines to research and hopefully improve each units performance both piston and jet engines. Piston engine research was just about finished when I was assigned to the ERD.

Im a new viewer and I’m not sure what I just watched here but it looks amazing

Excellent seems to run very well, I was thinking a while ago about if an air starter would work - compressed air in the cyl type

wow fantastic love it she runs all the best man looking forward to seeing it go down the road

That is wicked cool what an amazing piece of machinery.

Outstanding! 🤘💪👌👍

Congrats! Awesome achievement!

Awesome mate really pleased for you and Mr Bob great job 😎😎🤘🤘🇹🇭🇹🇭

Excellent can't wait to see it roll down the road now.

just found out your channel, my lord, what kind of engine is that!? haha now i need to dig more into your videos, greetings from México.

Forever and ever Even growing up when I was like 12 yrs old I would look for videos of one of these running. Absolutely awesome what you guys have done and it sounds amazing. The Napier sabre engine is artwork always found it amazing how much power it truly could make. Very very cool beyond cool. Subscribed it's so cool.

Give new meaning to the term, BIG single!! Seismic!!!

By golly this thing is bonkers and I'm blown away by how well it runs for a first start, very impressive indeed 👌🏻

Wow! That is really something special! LOLZ!

I JUST GOT HERE, holy fvck what a BEAST. SUBED

It's alive!!! It's got a sound all of it's own. Timing and carb to sort now. Well done all!!!

I'm not sure what I just came across but I just subscribed...

Amazing work!

Now that is a thumper👍

Excellent I love this build 👍👍👍👍 I would beef up the engine mounts..you can see the engine moving in and on its mounts.. vibration will break lots of things...!

Awesome, congratulations 🎉

Brilliant!!!!

Great achievement guys! Hate to be living next door tho 😂

I had my doubts, but congrats.😊😊

Wow. Incredible build.

Just the job for riding around Sadiq Khan's Ulez zone 😂

I especially like the exhaust system.

Well done!

AWESOME!! It runs.

the king of the thumpers

That's savage !!! Yiewwww

Looks a little rowdy but congrats looks amazing

Fantastic!!

Congrats this is awesome 😊😊😊

absolutely brilliant

Awesome, possum!

Well done, its a runner ! :)

Congrats!

Great work. Well done