Author Topic: B25 Difficult Starting  (Read 780 times)

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BANHAM

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B25 Difficult Starting
« on: 31 March, 2017, 20:18:46 »
I have a 1969 B25, which I have just finished a nut and bolt restoration. When running it performs well, no flat spots, never misses a beat and accelerates well. I've just completed 350 miles and its last run was over 150 miles. I am running with a Boyer mk4 electronic system and a new Mk1 Concentric carb.

 BUT from cold the only way it will start is zero throttle, flood carb, find TDS on the kickstart and kick.  If you are lucky after the third or fourth kick it will start and when the rev's pick up you can open the throttle, otherwise opening the throttle will stop the engine.

When its warm , starting is in the lap of the gods, sometimes with throttle, sometimes without.

 



MICKREEVES

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Re: B25 Difficult Starting
« Reply #1 on: 21 April, 2017, 18:51:13 »
I have just discovered a way of starting my C15 SS, from cold, First kick every time.
with the throttle stop set for a good idle when cold, I dont choke or tickle, or touch the throttle.
As it warms up, the stop has to be turn back lower for hot tickover.
To find the starting setting again, I have soldered a piece of piano wire into the throttle stop screw,
so that I can easily see or feel exactly where it is.
Mick

TIGER

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Re: B25 Difficult Starting
« Reply #2 on: 23 April, 2017, 06:04:01 »
Hello
       I have some difficulty starting my. C15SS FROM COLD.
       I noticed some pictures from Julian show an additional lever on the handlebars.
       Is this a choke which could help !
        I have a Amal 375 (I think standard fitting)
        Where can I buy this fitting ?
Regards
           Tim

JulianS

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Re: B25 Difficult Starting
« Reply #3 on: 23 April, 2017, 10:21:14 »
You will need an air slide, spring and guide for the carb and a cable and handlebar lever.

All the carb bits can be obtained from Amal

http://amalcarb.co.uk/

The lever and cable from your favourite dealer.

These bikes should start easily with or without the choke - tickle the carb switch on ignition slightly open throttle and kick. Make sure the carb throttle slide is raised enough on the throttle stop to allow a little air through otherwise no petrol will reach the engine.

BANHAM

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Re: B25 Difficult Starting
« Reply #4 on: 23 April, 2017, 16:23:04 »
Problem solved, I've fitted the next size pilot jet and she starts first kick with throttle. The nice thing about a Concentric MK1 Premier Carb, they are easy to change. Many thanks for your help.

Starphil

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Re: B25 Difficult Starting
« Reply #5 on: 02 February, 2018, 12:34:33 »
I came across this post because I'm having exactly the same problem with my 1970 Starfire. What size jet did you fit?

ANDY HIGHAM

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Re: B25 Difficult Starting
« Reply #6 on: 02 February, 2018, 23:17:27 »
The choke slide will have no effect at all when starting with a closed or slightly open throttle as it will be hidden inside the main slide

MICKREEVES

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Re: B25 Difficult Starting
« Reply #7 on: 03 February, 2018, 14:34:37 »
In addition to my last reply
I have discovered a way of starting my B44  from cold, First kick every time.
I have fitted a wire handle to the throttle stop. this Will be to the rear for normal tick-over when the engine is hot.
For cold start -  I move the stop lever forwards, which opens the throttle a little.
I turn on the fuel tap. press the tickler until fuel drips out. Then turn the engine to compression, ease it past with the release lever.
One good swing will start the engine. The tickover will by too fast, so I would just ride away and readjust the throttle stop for a slow tickover later.

With my c15, with the throttle stop  on fast  tickover , the one kick and its running. (Fuel tap still off, ignition direct from the engine flywheel.
Mick