still not starting

[rhyatt]

Or , as suggested speak to burlen.
I credibly helpful and knowledgeable

[neil1964]

Carbs sitting unused for a while with modern fuel (E10) will fur up their pilot jets and cause a lot of the symptoms you describe.  It can also damage the float needle seat (depending on the material in yours).  Trouble shooting for this was a PITA as I found it hard to believe that something so simple could cause the problem, similar to just dirty fuel.  By the time tank flushed, filters cleaned, spark plugs in/out shake it all about it was quite frustrating.
Depending on your model are these your settings?:
7/8" Bore
140 Main Jet
105 Needle Jet
25 Pilot Jet
4.0 Slide
A genuine service kit would be an excellent idea.

[Kernowpete2]

Is it definitely leaking out of the tickler? If it's leaking out of the joint face then the pilot jet might not be pulling in fuel from the bowl. Assuming it's a concentric carb. Both bikes I have have concentric carbs and I've had to flatten both float bowl joint faces on a piece of glass with fine wet and dry to stop them leaking.

[neil1964]

Just saw my above post. Not 7/8" bore
Much more like 626 (26mm) ?

[Barnsey]

I am not an Amal connoisseur but I understand that the carburettor which I have fitted is the original Monoblock and they cost a packet to replace.  The bell mouth on the concentric is bigger.  Has anyone managed to fit the concentric without having to enlarge the hole in the air box? 

[neil1964]

The inlets should be similar size.
Just unscrew the bell mouth.

[Barnsey]

Actually I am sure the concentric had a larger choke.  Maybe the who thing was completely the wrong size.  Hhhmmm!?    I've found the correct jet sizes so I reckon I will buy a service kit for the carb I have, in the first instance, and then go from there.   

[Barnsey]

Hi, 

    I've been doing various odd jobs on the bike for a few weeks, during the cold weather.  Now I am back to starting it and I am back to the drawing board.  Lots of straining and cursing, but when it does eventually start it does so really easily.  I am reviewing the notes in this thread,  but I wanted to push this back up the list in case anybody else has any better ideas.  .

   BR,  Ian

[Barnsey]

I made a perspex cover for the carburettor today, and, although it cracked straight away, it showed me what I wanted to know. The bowl is overfilling by maybe a quarter inch.  In fact it may not be shutting off properly at all but flooding the engine.  I noticed fuel in the air filter hose.  A total pain because the petrol strips the paint off of anything it touches. 

 So.  Where to start?  There seems to be no float adjustment. DO I need a new float or a new needle ?   

[Barnsey]

BTW  there are no shims under the banjo, so the only adjustment is upward.

[Barnsey]

I've ordered a new floatkit of the stay-up ethanol proof variety.We will see if this helps at all.   

[DAVE BRADY]

Hi,

The new float and needle may do the trick but ultimately a new carb may be the best solution as the inner air/fuel ways will be worn and corroded.  7/8" is 22mm

Dave.

[Barnsey]

Well...  That was the start of the sad saga.  A mate advised me to buy a new carb, but monoblocks are expensive, so I ordered a concentric, but it didn't fit in the space available.  If anyone can advise so that I can buy exactly the right one this time it would be appreciated.  I don't want to be modifying the airbox to make it fit.

[DAVE BRADY]

Hi,

I seen concentric carbs on C15s but cannot say for sure if the air box was modified.  Someone on this Forum must have done it. I have just fitted a 22mm Mikuni to a '62 C15 and it work well. A bit of a fiddle getting it on and it will need a bespoke bit of rubber to connect it.
Have look on Motocarb.

Dave.

[Barnsey]

Thanks Dave!  Mikuni carbs are not a cheap option either, but I will bear it in mind. 

  My dilemma is that that, even after 2 years of work, I haven't ridden the bike yet.  I'd prefer to keep it cheap until I have had a test ride. I don't want to spend the best part of £1000 on posh carb, electronic ignition etc, and then decide that it isn't for me and sell it.   However, one way or another I need it to start and run.  Keep watching this space!