Convert Dynamo to Starter motor

General purpose topics/chat goes in here
User avatar
NZMatchless
Posts: 18
Joined: Sat Mar 16, 2019 8:48 pm
Location: Essex UK

Convert Dynamo to Starter motor

Post by NZMatchless »

I have a 53 G9 500 twin, and, as ive got older and have dodgy knees, Im finding it more and more difficult to kick start the bike. As anyone ever converted a Dynamo to a starter motor?
Ride New Zealand - Live the Dream
SPRIDDLER
Member
Posts: 8542
Joined: Wed Sep 01, 2004 1:00 am
Location: WEST SUSSEX UK

Re: Convert Dynamo to Starter motor

Post by SPRIDDLER »

One of our bike dynamos (or any other dynamo) wouldn't produce sufficient torque.

I had a Lucas Dynastart (dynamo & starter)on my 6hp single cylinder Volvo boat engine but it was a mighty big and heavy unit.
I also had a Villiers engine with a combined dynamo/starter on my 3 wheel Bond Minicar back in the mid 60's.
My choice would be to use a separate modern bike starter unit from a breaker. Haven't thought through how/where to fit it though ........


The basic principle of a dynastart is that it has two sets of field windings which are taped together into one physical coil. One of the field windings has few turns of thick sectional copper, like a starter motor. The other has many turns of round wire like a dynamo field coil. The armature is wound like a starter motor armature.

When the unit is first turned on it acts like a two pole series wound starter motor. Current flows from the battery through the armature and through the heavy strip-wound field coils. The physical reaction to the magnetic field causes the armature to spin.

The resistance of the field windings is very low, as is that of the armature. This means the unit will draw a large current which would not be possible if the armature and fields were wound like a traditional dynamo. This part of the design is ideal for a high torque output, required for starting the vehicle.

When the engine is running, the dynastart acts like a dynamo and this is when the second winding in the field coil comes into play.


Back in 1961 I made a cart with a starter motor driving one back wheel from a battery and a dynamo being driven from the other back wheel in the belief that it would charge the battery and run forever. Ah, the innocence of youth! All I got was smoke :roll:
'There is a tide in the affairs of men
Which taken at the flood............'
Mick D
Posts: 2886
Joined: Mon Mar 24, 2014 5:44 pm
Location: Aberdeenshire

Re: Convert Dynamo to Starter motor

Post by Mick D »

Hi

I have a Lucas starter motor on my T160, it's twice the size and weight of an E3L dynamo.

Alton do the 'electric leg' which may be adaptable to fit your needs but it's expensive and would represent a considerable engineering challenge.

https://www.alton-france.com/norton-sta ... kitnorton1

Thinking outside of the box - have you considered lengthening the kick start lever or dropping the compression ratio? - both would make starting less of an effort.

Regards Mick
bob121
Posts: 291
Joined: Sat Jan 14, 2017 11:48 am
Location: WEST MIDLANDS UK

Re: Convert Dynamo to Starter motor

Post by bob121 »

A modern denso unit wouldn't be any bigger than a dynamo and wouldn't be too expensive from a breakers. But then there is all the trouble of fitting.
Plugsnpoints
Deceased
Posts: 598
Joined: Sun Oct 07, 2018 11:36 pm
Location: Essex UK

Re: Convert Dynamo to Starter motor

Post by Plugsnpoints »

If it's any help my friend has fitted an aftermarket electric start kit to his Commando. It was pretty expensive, but it might be worth looking into if they could be adapted to suit other bikes. I guess one of the problems could be having to fit a high amperage battery in the box?
ksj_LAPSED
Posts: 210
Joined: Tue Mar 06, 2012 11:55 am
Location: CHESHIRE UK

Re: Convert Dynamo to Starter motor

Post by ksj_LAPSED »

i am sure that somewhere on this site there is an article by a canadian gent who made an electric starter for one of our bikes he casted and machined a new primary chaincase and made a new clutch basket with a starter ring on it
User avatar
rex.webb
Member
Posts: 2947
Joined: Mon Jan 01, 1990 12:00 am
Location: CAMBRIDGESHIRE UK

Re: Convert Dynamo to Starter motor

Post by rex.webb »

I AM SURE I HAVE SEEN WHERE THIS HAS BEEN DONE ?
Thinking outside of the box - have you considered lengthening the kick start lever or dropping the compression ratio? - both would make starting less of an effort.
SEEMS AN EASIER WAY ?????????????
RIDE WITH CARE AND LIVE LONG
TO ENJOY YOUR
MOTORCYCLING ans SCOOTERING
r w webb
User avatar
spookefoote1956
Member
Posts: 1836
Joined: Mon May 01, 2017 7:32 pm
Location: Wales Innit

Re: Convert Dynamo to Starter motor

Post by spookefoote1956 »

ksj wrote:i am sure that somewhere on this site there is an article by a canadian gent who made an electric starter for one of our bikes he casted and machined a new primary chaincase and made a new clutch basket with a starter ring on it
I've tried to find him before to no avail.

Alton do not and have no intention of making an AJS / Matchless kit. I asked!
Hail Joe Lucas ............ Prince of Darkness!
All my bikes are original........ to me!
"Creativity is your intelligence having fun" Albert Einstein
SPRIDDLER
Member
Posts: 8542
Joined: Wed Sep 01, 2004 1:00 am
Location: WEST SUSSEX UK

Re: Convert Dynamo to Starter motor

Post by SPRIDDLER »

Using a twin's existing dynamo is a non-starter ;) :roll:

I would've said that of all the AMC engines the 500 twin is probably the one that requires the least effort to kick over. After all, it's only 2 x 250cc cylinders. However I'm personally very aware of the limitations of a mature and accident damaged body :(

There are several electric starter conversions, home made and commercial, but as far as know all bar the Alton unit are for singles when the practical installation challenges are less problematic than for a twin, although I recall seeing just one for a Vincent 998 twin. The Alton kit is about $2000.
(but Vincent owners are rather wealthy ;) )
'There is a tide in the affairs of men
Which taken at the flood............'
Groily
Member
Posts: 2151
Joined: Thu Jul 04, 2002 1:00 am
Location: NORMANDIE FRANCE

Re: Convert Dynamo to Starter motor

Post by Groily »

It's been done on some other classic twins, eg BSAs. But that's with alloy chaincases not flexi-tin, and there's a bit more space, comparing my Mod 20 with my s/arm A10.
For one example on a Super Rocket, see

Although the 500s are very easy to start when warm, 0° and cold oil can still make 'em a bit slow on the kickstart . . . Sometimes needs a pretty good prod in winter, does mine.
Locked