Mk1 Concentric bad starting from warm

Bill Thomas

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Just got back from first ride of the year, Gave a lot of thought to bad starting over the winter.
Just picked up a pair of Mk2, Bit of a joke, When I looked inside , Half the bits are missing, Don't buy unseen bits !!.
Anyway,Because of this rubbish Petrol, I have to run weak, Or the plugs will foul.
Back to Mk1,s, I have not been flooding enough !!. Partly because I don't like petrol all over my nice clean engine.
And a life time of a mechanic say's I should not !.
So on a hot day, Down on the coast, Quick chat, Then time to restart, I am being watched !, Gave it a real good flooding, Thought this is never going to work,
Starts first kick, Went round the bay a bit more, After a short stop, Same thing, First Kick, I can't tell you how much I have been kicking this bike these last few years,
Since I took my T.T. carb's off.
Learning All The Time !!. Cheers Bill. P.S. I have not touched the Carb's or Plugs etc over the Winter, Left old petrol in there.
 

greg brillus

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Bill, If you find you are kicking many times and not firing it is a good idea to stop and remove the plug to see if it is wet (flooded or too rich........Float level or similar) if not then you are too lean. i find it is a fine line between too lean or too rich as you know they all behave differently. Most Mk 1's respond to tickling till they dribble out the button............Only other thing could be if the slide cut away is too large even a small change here will affect how it behaves, and the slide numbers differ from each model of carb too...............;).
 

Bill Thomas

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Cheers Greg, But we are talking about a hot engine, Everything tells me not to flood it, I am too old to do all this kicking.
This is a L/ning spec motor, Starts first time after stopping for petrol, Runs below 40 mph easy, Ticks over nice,
Pulls like a train !, Compared to a standard bike .
Mk2 Robinson cams.
I had to hand cut the slides, Weak, Or it will wet the plugs, Might be a bit oily, Old Specialloid, Race clearance.
Rita ign'. Very strange. Cheers Bill.
 

greg brillus

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Bill, I found most Brit bikes with amal carbs like no throttle when starting from hot, this can be difficult when you swing down on the kickstart lever, as your hand tends to open the throttle. Cheers...........Greg.
 

Bill Thomas

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Morning Greg, I know what you mean, But I have been playing with all sorts of carb's for years, We even made our own Wal Philips type fuel injector.
This bike never spits back, ie weak, Even on cold days, And yesterday was Hot for UK.
I know it's this Petrol, And they say they are going to put more of this stuff, Pee !!, In it in years to come.
Cheers Bill. P.S. Happy Birthday Marcus.
 

vibrac

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Morning Greg, I know what you mean, But I have been playing with all sorts of carb's for years, We even made our own Wal Philips type fuel injector.
This bike never spits back, ie weak, Even on cold days, And yesterday was Hot for UK.
I know it's this Petrol, And they say they are going to put more of this stuff, Pee !!, In it in years to come.
Cheers Bill. P.S. Happy Birthday Marcus.
Have you tried Esso top brand Bill they are the only petrol company with the guts to say ethanol free on their web site.
However I should add that I have recently had reports that some paint removal problems have still been noted with even this brew (who knows what other stuff they add) when I get a chance I will do a ethanol check in a jamjar
 

Bill Thomas

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I have got one of those, But it's not on my normal ride, I like to leave the house and fill up 1/2 a mile away,
Don't want any running out of petrol !.
It gives me a chance to see if the bike is OK before going too far, Silly habit I know, But that's who I am !.
Cheers Bill.
 

Albervin

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Modern fuel is weird. I have standard carbs on my B Rap. with 190 main jets and 3 1/2 slides. Cold, I lightly tickle front carb, find the correct stroke and kick through with a bit of throttle. Fires almost every time. If not then next kick is with full throttle and that always works.
 

Bill Thomas

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Tis Strange, My 28mm concentric slides are out to nearly 4, Tried going back a bit and break down in about
20 miles, I can't do messing at the side of the road, Looks bad with a Vincent !.
With in 1/2 an hour, 2 people asked me, How much and how long have I had it !.
I said to one of them, 53 years, And she said I must have bought it New !.
I can't bring myself to try Full Throttle, I saw Harvey do it on youtube, With his A Twin.
Funny thing is, My knackered Comet, Flash spec, Will start fine, With all sorts of Carb'.
Ron's Comet likes Full choke Mk1 concentric, I even put chokes on mine and it did work sometimes.
Anyway, I can still ride !, Magic. Cheers Bill. DSCN0015.JPG
 

greg brillus

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Bill, I think the Mk 1 and 2 Concentrics can tend to suffer from a float level that is too high. Modern fuel atomizes very readily which could cause partial flooding. A larger cut away can make an engine harder to start. If the carb is worn you might consider replacing it with the newer premier model, as Amal hardly sell any of the original spec MK 1 Concentrics anymore. I don't believe they are expensive to buy either. Cheers......Greg.
 
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