Ali Express Sprag

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The 18 tooth Chinese Sprag I purchased on Ali Express is working well. It has been in place for two and a half years now.
It was priced at $17 US. The seller was "Freewheels"
It's been working so well that I purchased a couple of spares. This seems to be the best way to insure that the first one will keep working forever!

I haven't used the kickstart on that bike in 2 1/2 years.
Starter is a 4 pole with big cables. It spins the engine fast, starts in a flash.
The bike has a tiny isolated booster battery in the circuit for full ignition voltage on cold starting. ( ancient low voltage sensitive Boyer)

Glen
 
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Hi Glen good idea putting a separate booster battery to give the Boyer the full 12V when cranking. I need to do something like that, I modified my starter to a 4 pole but the bike takes forever to fire when cranking, it fires straight away when kicking it over. Ted
 
Ted.c said:
Hi Glen good idea putting a separate booster battery to give the Boyer the full 12V when cranking. I need to do something like that, I modified my starter to a 4 pole but the bike takes forever to fire when cranking, it fires straight away when kicking it over. Ted
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I thought about an extra battery when I fitted an Alton starter to my commando as it already has a power hungry Lucas Rita fitted
But so far it's an instant starter as soon as I touch the button
Cheers
 
Hi Baz I haven't got the Alton stater I hear they are good. I modified the original starter with a prestolite brush holder then rewired the poles to get it running in the correct rotation a small booster battery should be a good fix also went to a nice LED headlight bulb which was a good help in keeping the Bat voltage up for the Boyer ignition and its brighter Ted
 
Look out for a DC step up buck rated at 4A to 5A, these will take a feed lower than 12V and boost it to 12V, saves the hassle of a second battery.

A 6A version inside a heat shield example.

Ali Express Sprag
 
kommando said:
Look out for a DC step up buck rated at 4A to 5A, these will take a feed lower than 12V and boost it to 12V, saves the hassle of a second battery.

A 6A version inside a heat shield example.

Ali Express Sprag
Click to expand...

I don't find the 2nd battery to be a problem at all, in fact the bike will kickstart and run on it if the main battery is dead, so it's also a good backup. The 12.8 v it provides to the Boyer gives almost instant starting cold and hot. Analogue Boyer will work down to about 11.5v but really likes 12.8v
My modern Triumphs are the same, cold starting is much easier at 13 volts or so.

The electronic step up buck is interesting.

I assume it is wired in series in the ignition circuit so that when the starter is cranking and system voltage is 11v, the ignition sees 12 v?
I guess the downside might be that it is one more electrical item that can fail and kill the ignition?

Glen
 
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worntorn said:
I assume it is wired in series in the ignition circuit so that when the starter is cranking and system voltage is 11v, the ignition sees 12 v?
I guess the downside might be that it is one more electrical item that can fail and kill the ignition?
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Yes, the one in the pic will send out 12V as long as its gets a minimum of 6V so a starter motor dropping the voltage to 10 or 11v would mean the boyer still seeing 12V. It will also protect the boyer from a failed voltage regulator.

Yes it another box to go wrong but then so is an extra battery, its gets +ve from the ignition circuit and -ve from earth circuit or battery and then feeds +/- 12V to the boyer.

The one I have is not in a box and is slightly different, it has a variable output which I set at 13.5V and has a circuit that takes higher and lower feed voltages and converts both to 13.5V. So like the pictured box it is dual role.
 
Maybe the one pro for an extra battery is if it goes bad it you still have ignition off the main battery, or if the main battery dies the tiny battery will take over ( disconnect main).
So in that way I see it as an item which, if it fails, the bike still runs, plus it can turn on the ignition in a pinch ( main battery failure) vs an item that can shut off ignition if it fails and won't help with main battery failure. ( Or will it?)
The con is the battery will need replacement every few years whereas the voltage buck could live a long time.
 
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I have had 2 batteries fail in motorcycles and they would have stranded me except for the 2MC, 2 in cars that did strand me as no 2MC ;) . Now that is in 35 years of riding and driving but they were sudden and terminal, so a box I can take out of circuit if it fails is not that different to a second battery.
 
kommando said:
Look out for a DC step up buck rated at 4A to 5A, these will take a feed lower than 12V and boost it to 12V, saves the hassle of a second battery.

A 6A version inside a heat shield example.

Ali Express Sprag
Click to expand...
Hi Kommando
Would you by any chance have a link to buy one of these?
I've found similar on Amazon but not exactly the same
Cheers baz
 
I have Pazon ignition with the Norvil modern starter on a Mk 3 motor, and works very well. I read that it works well at lower voltages, so bought it.
 
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