Royal Enfield Constellation - Cause of the left cylinder not running right discussed & explained.

[@georgemoskal2098]

The more I watch your videos the better my bike runs, thanks Paul.

[@aeroearth]

Well done Paul! Nice bit of sleuthing out! That problem of induction faces being out of parallel is another downside of having the cylinder barrels and heads separate to each other. Watch out for oil leaking onto the magneto's pick up ring as the phenolic wears faster than the brass which the HT pick up brushes have to follow.

[@andrewslattery403]

Great explanation - very happy to see that this fine machine runs on two cylinders at all engine speeds. I recall that the inlet manifold on my Constellation would occasionally become loose. This was always accompanied by popping in the exhaust on the overrun. I've still got, somewhere, the spanner that I had to cut down to allow me to tighten the inlet manifold nuts, especially the two that are underneath the manifold!

[@philmuskett265]

From consternation back to Constellation!!! Well done.

[@4ager505]

Well, now that the cause has been determined and remedied, it is obvious that the suggestions I offered were no help. I hope I did not take your attention away from the actual problem. So glad that all turned out well in the end. Nice that you shared the entire experience. Your account of this is certainly valuable to those of us who have never worked on one of these great machines, but still hold the hope of doing so, someday. Thank you for showing the complete saga. Best regards from the USA...

[@norsehall309]

G'day Paul, you have done a great job on that Royal Enfield, the information available online and Comments from others really helps solve these little problems, how many bikes have been thrown on the scrap heap because they where unable to find out how to repair it, cheers mate, Neil 🤠.

[@pw601]

Well done! Funny little nuances of old motorcycles. Inlet manifold leaks, resulting in a lean condition until the higher RPM. Won't have shown up on a compression test or a leakdown one either.

[@andrewgent5887]

In the past I’ve sprayed a little white spirit around the manifold sealing faces with the engine running, the ensuing telltale white smoke from the exhaust usually confirms any leakage.

[@bsa_brummie7775]

Great news, glad its sorted and the fault was able to be found and explained. 👏👍

[@paulhenshaw4514]

Thanks 👍

[@scienceistruth1924]

The warping of twin carb manifolds is a common problem in old MG Midgets/Sprites "A" Series engines, and grinding them flat again on a sheet of plate glass with fine grit wet n dry is often required. Good spot though, what a pain!!

[@IVAN-bs5bq]

I bought one of these out of a front garden for £5 in the late 1960's complete with a double adult sidecar that I never collected , happy days now long gone .

[@williamnethercott4364]

Well done Paul! I think that would have foxed most people, including me. These air leaks can show up in different ways and I never feel 100% confident that I've fitted my carburettor right. I hadn't thought of putting sealant there but I might look at that the next time I need to fiddle about with the inlet system.

[@IVAN-bs5bq]

Better lapping them in on sheet of glass with grinding paste .

[@paulhenshaw4514]

@IVAN-bs5bq Fine, if you want to mess about taking a head off when a new gasket and some sealant will fix it in situ.

[@mattyb7736]

​@@paulhenshaw4514got to love hylomar blue for this, stays soft and seals like the proverbial on a blanket. 😂

[@geraldfitzgibbon7428]

Its a hansom lookin bike welldon for all ur work

[@borderlands6606]

In the words of Sherlock Holmes, "when you have eliminated the impossible, whatever remains, however improbable, must be the truth.."

[@Cobra427Veight]

On my 750 commando , i fitted new throttle cables , synced etc all ok and after a while it started to miss from idle to giving it a rev , it turned out to be , the outer cable clearance had too much free play and one cable got cocked , so one of my slides was going up about 5mm sooner , ! . Cheers

[@mickhardstaff6605]

I'm glad its sorted Paul , talk about trial and error 😂.

[@ryanrodgers1826]

hi Paul you got it in the end job well done. ride safe out there cheers

[@hermangibbs8163]

Thanks Paul.

[@mrmr9767]

The first Constellation 1958 had an Amal TT carb on it. Then went to two carb.

[@PeterWW-W]

Wow, again my respect Paul.

[@anthonyhull2998]

Well if I can help and support your good work I 'm happy to do so . T

[@Paul-pb3vq]

The old saying goes. You learn something new every day. Bottom line you got there in the end. Well done.

[@p--n]

Thanks for sharing the trials and tribulations, warts and all. We all appreciate that you take the trouble and the associated highs and lows on our behalf to keep these mechanical beauties breathing and continent.

[@JohnCampbell-sl5nx]

As a matter of habit I always ues a felt tip pen on the manifold face and gently sand down till no ink shown , just to make sure of a good seal, but yes I've been stumped many times till the penny drops.🙏.

[@stevec-b6214]

As my wife would say to me - I was just going to say that`s what it was!

[@TornadoCAN99]

Good find. Is silicone sealant a good idea on an intake flange surface? I've found it softens/dissolves when exposed to any gasoline. Perhaps WellSeal or one of the Locktite Gasket making compound like number 513 which is not silicone based and fuel proof, would be better suited?

[@mattyb7736]

Hylomar blue works like you wouldn't believe. Its designed for aircraft and nothing on an engine will dissolve it. Stays soft and like a viscous gel.

[@bananabrooks3836]

A pretty comprehensive review that Paul, a good learning experience. Easy to see in hindsight where one goes down the wrong fork in the road. Those who've never done that can 'cast the first stone'😁

[@paulhenshaw4514]

Thanks 👍

[@billykershaw2781]

Nice one.

[@nickmarshall9192]

Excellent work Paul as usual Out of interest how hard are these bikes to kickstart? Compared to a 750 commando for example? Cheers

[@andrewlengert2558]

I fitted twin carbs on my super meteor, the thing that surprised me was the twin carbs had bigger main jets than the single carb, still to this day don't understand why. Also someone told me years ago if you suspect an air leak spray on talcum powder on manifold to see if it mists, or wd40 or similar to see if it runs better

[@bananabrooks3836]

The 'vacuum' sucking the quantity of fuel up the main jet through the single carb is greater than the vacuum with two carb venturis which 'pull' less fuel. To compensate the jet orifices are larger.

[@andrewlengert2558]

Thanks, nigh on 40 years that's puzzled me

[@4speed3pedals]

I would have filed the carburetor adapter flat or placed a piece of 400 grit sandpaper on a flat surface and then sanded the surface smooth. Chevrolet used aluminum carburetor bases on the 230 cu. in six cylinder which were held on with 3 screws and they were prone to warping. Filing with a mill file would cure the vacuum leak. IMHO, doubling the gasket works but the pressure is still on the ears allowing the center to warp possibly more. It may not happen but I prefer addressing the manifold.

[@vintagebike_ger]

The problem is not the manifold. The Enfield has two seperate heads, not a single like BSA or Triumph. So if you mount the heads without the manifold the inlet ports can be missaligned and cause leakage. I cut the manifold in the middle on my Constellation so you can mount a single manifold to each head seperately.

[@4speed3pedals]

@@vintagebike_ger I did NOT catch that tidbit of having 2 heads. I meant no offense and I was stumped as to why you used 2 gaskets vs. flattening the manifold. That does make a difference. Thank you for giving me this info. I must have missed it in your videos. Sounds much like a Triumph, to me. You discover things that most miss. Love how meticulous you are.

[@SLED-55]

Thanks again for your teaching moments Paul!👍

[@neilmcintosh1200]

Ah, so an exorcism did do the trick. Presumably the same fault can trouble Norton Unit twins and AJS/Matchless twins.

[@basilwatson1]

You could have saved yourself a lot of time with an Oscilloscope plug traces would have told you quite a lot imho Scopes are very cheap these days

[@track1219]

I didn’t realize the heads are 2 separate pieces.