Carburettor choices

Bill Thomas

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It was always a joke that they won't start when people are watching :D .
I think as we get older, That doesn't help, Maybe a bit of stress, Or is that just me ?,
But if it doesn't start quick, It's easy to get it wrong, And this petrol is Pee !,
On my Bikes it took me a long time to work out when warm, It needs flooding or choke,
Which is totally wrong for an old mechanic,
But my Comet is fine most of the time.
 

Hicam

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Thank you for all your replies.
It's cold starting I am struggling with now. I have decided to take the carbs and fuel lines apart and check for foreign matter.
I will do a compression test but when I first rode it in the late last century it climbed Hardknott and Rynose passes in the Lake District which are hairpin 1:4 hills without a problem even with its Norton clutch conversion!
I have tried feeling for compression and the variations of front and rear cylinders!
A local member is going to take a look at it for me next week, so I will keep you posted.
Regards Chris
 

Mark Stephenson

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Hope to hear a successful conclusion to this interesting read. Also have a new to me '50 Rap B coming to me next week so taking notes:)
 

Bill Thomas

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From cold, Forget the chokes and give it a good ! flooding, With new plugs It has to start ?.
As I said on another thread, Get someone to give you a push start in first gear !!, Some say use second gear,
But work out how FAST you would have to push !!!,
For me, First is the one to use, Just to prove it's a runner.
 
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vibrac

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As the title of this thread is Carb choices I would put down my thoughts

Original 276 Family Great Carbs not a lot wrong with originals except wear after all this time and I dont know about their new expensive copies.
Monoblocks again not a lot wrong wear a bit more prominent as the bean counters moved in on quality
Concentrics I have only met these 2 variations on other peoples machines who had a lot of problems with tickovers and having to drill etc I believe the latest versions have improved I would not take them off if I bought a bike with them on, but I would not buy one to put it on a bike I had.
Mikuni Cannot fault these once Allens have set them for a machine and the rubber fixing has been sorted I miss the tickler and also have to think hard about the choke but thats just habit
TT Had a lot of time with these wouldn't hesitate to use them on the road but alloy body can wear fast
GP Ditto TT but not cheap just got a big pair for the racer (ouch!)
Bing,Del Auto etc etc no idea I have two Bing to sort on a BMW ...
 

Chris Launders

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I am with Bill, flood it and kick, I have concentric's on mine and flooded it is normally one kick, I don't use the decompressor but have the advantage (for this anyway) of weighing 20 stone, I don't have chokes.
 

brian gains

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10 kicks + and I'd be thinking the motor was flooded so do the usual of crack it wide open and full choke, although with a valve lifter shouldn't you be able to clear flooded pots?.

on the twin i can't fault the Mikunis although early days so far. Trouble with rear carb' over flowing seems to have cured and probably was due to standing idle too long. Other than that i have just leaned out rear by using smaller needle jet and using 3rd groove as opposed to 1st groove with P2 jet, slightly browner appearance.

i don't want to jinx it but the twin starts so easily (when all is right) that I don't use the decompression lever, I always thought deco' levers were relevant to 40's - 50's man who maybe was less in stature and weight than his later counter part.
 

Bill Thomas

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And if you wet the plugs, Put them in the BIN, Spin the engine over with the plugs out to clear it,
And with new plugs start again.
 
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