Ready! 

Keep us on a knife edge, why dont you???!!!! Looking forward to the big day.

It seems like a massive two stroke

For most fabricators it is very exciting for you to share this project with us...... We get to enjoy this journey with you

Looking forward to seeing this roar to life. Well done to you and Bob... Keep up the good work.

Gutted I can't make the fire up, best of British luck buddy🤞

You deserve to celebrate for all that you’ve accomplished up till now!

Good luck! I'm already VERY excited! 👍

I would reduce the compression ratio perhaps down to 4:1 as there is a huge amount of force from the 3 litre when it fires and it would help in throwing it over tdc. I would also support the bike adequately to reduce the vibration, perhaps have it resting on its wheels with some stabilisers - just for the initial firing in case it’s quite lively. Do you have any way of advancing/retarding the ignition on first firing? This would be very useful, also you need a good, fat blue spark that is strong enough to cope with the high compression. I admire you and Bob’s work very much, and am very grateful that you post these videos and keep us updated. Men in sheds, brilliant.

Looking bloody magnificent, bravo!

You don't need that sort of spring pressure on the decompressor, everything apart from the suction during induction is trying to keep it closed. Good luck with the start up.

I worked on a single-cylinder diesel Hand Cranked piece of construction equipment, that had a "smart" decompressor that was activated by rotating a lever, stayed open for three cranks, to give you a chance to get the flywheel up to speed, then snapped shut. Your reed valves sound like a good idea. Some big-bore motorcycles use a decompressor, also two-stroke chain saws, never thought about the carb.

I know that this question has been asked before, but I can't remember your answer. Aren't you worried about dirt, debris, and rain being collected around the spark plugs and decompresser valve? Beautiful build.

Great workmanship

Good point re deco valve. I think you will need a shim steel reed valve on there to stop that huge piston pulling the deco valve open. It would also serve to stop anything falling into the cylinder through the relief holes.

Such a nice looking bike :) Thanks for sharing.

Hanging on the edge of my seat here .

At last, so close, cant wait 😊

Good luck, great project.

Might be best to move the ignition kill switch away from those fire breathing exhaust ports.

Do hope the chain has enough clearance to the fuel ? Tank as when it starts to stretch with the fireing pulse from that big single cylinder you may develop a high spot and start sawing at the bottom.

Bristol n ship sleeve shape got to give her a name furious looks like a good name??? 🎉

I am sooo looking forward to 'first light' ! 🤩🤩🤩.To prevent there being a circle of 'blow-torches' , it may be an idea to disable the spark when the decomp is activated and the engine turning over. (Spikes of blue flame tend to mar the paintwork and spoil the effect).

Please realease the first start attempt video tomorrow 🙏

The decompressor lever could push down on a little piston filled with petrol as it closes, with a little nozzle directed into the decompressor holes. Maybe a recipe for a a little fireball but itd get extra fuel in at just the right moment.

I still think it'll need an oil cooler and a bigger oil tank; very excited for the start-up though and wish you success. (You've no doubt got it in hand, but have a fire extinguisher ready just in case.)

Beautyfull build!!!!❤❤

Looks awesome,slightly dangerous, can't wait.

It's a pretty cool looking engine. But I can't help to think how much it looks like a Nuclear Reactor 😅 Just found your channel and planning to go back to watch what I have already missed out on. Looking forward to coming back to see the engine fire up for the first time 👍

is that the "finished" decompressor, or just an interim part? IMHO, i reckon you'd need a slightly longer one with a knob on the end, like for the gear selector.

Live show startup? :D

Starter fluid would be a better choice, it's combustible over a wider range of AFRs and generally easier to ignite. Anyway, don't take it too hard if it doesn't fire up right away. Getting to this point is a reason to celebrate in itself no matter what.

Waiting with bated breath.

Das ist mal n richtig fetter Einzylinder....naja,mein Moped hat nur 250ccm,aber macht massig Spaß 😁

I'm subscribed now. How have I missed this bike being built on RU-vid until now?

area... decomps dont need much area, theyre only a decomp. they arent there for flow performance. they can be small... very small. the less area they have, the less spring pressure required to hold them closed against that intake vacuum... old victa mowers "zip" starter was a small vacuum actuated poppet valve. been a long time since looking at one, from memory its just automatically opens up when the engines stopped. then combination of combustion pressure and vacuum on a diaphgram to keep them shut when running. been three decades since i saw one! most chainsaws and demolition saws are running the decomp button... again, just a small poppet valve, with a ball and detent retainer. stiff enough to resist that intake suction when closed... all that being said, maybe rather than brutal and archaic lever and fulcrum, consider rotating cam come lever with locking detent, or an overcenter toggle to actuate valve AND lock it shut? iunno, each to their own... but i work on an engine, the FIRST thing i do is pump some fuel in and kick it over to make sure it fires up..

Great

Another thing to be conscious of, regarding the decompressor... You noted that if the decomp valve is open during intake air may come in there, instead of through the carburetor, so you won't get fuel...that is overlooking an important part. The carb is (usually) closed during intake, and even if open, it is a restriction. Especially if the choke plate is closed! More air will flow in through the decomp valve than ever could through that tiny carb! You are cycling more unfiltered air in & out of the cylinder to crank with it open than the engine uses at redline with the throttle wide open! That could make for an exciting video if there is fuel in it. i think my idea for a timing altering decompression system will avoid that issue, somewhat. With timing advanced the intake port will open during exhaust stroke, so it will blow through the carb backwards. The carb won't add fuel to the air, again, but what was there will be there...

That carb looks way to small

First, yes

:O

I wonder if we had the same mode pulse jet as kids? I immediately knew what you meant by "petals!"😂

You bleedin tease 🤦🏻‍♂️😉😂

Tense with Antici