BSA Owners' Club Workshop Discussions

The BSA Workshop => Twins => Topic started by: DAVE BRADY on 12 May, 2024, 18:59

Title: Arc Engineering Electric start
Post by: DAVE BRADY on 12 May, 2024, 18:59
Hi,

Has anyone bought and fitted or even seen one of the Arc Engineering electric start kits for the A50/A65?

Dave.
Title: Re: Arc Engineering Electric start
Post by: Lone Wolf on 12 May, 2024, 20:01
Quote from: DAVE BRADY on 12 May, 2024, 18:59
Hi,

Has anyone bought and fitted or even seen one of the Arc Engineering electric start kits for the A50/A65?

Dave.

Wotcha.

Yes - I've fitted one to my Thunderbolt.

There were a few "teething troubles", most of which have now been sorted out. 
With any luck, folks who buy the kit now, shouldn't have any problems.

The only niggle is the clutch, which now runs dry and tends to grab ( well mine does ) - I'm currently working on a cure for that.
Title: Re: Arc Engineering Electric start
Post by: DAVE BRADY on 12 May, 2024, 20:32
Hi,

Will you be taking it to the National Rally?  Keen to see one.

Dave.
Title: Re: Arc Engineering Electric start
Post by: Lone Wolf on 12 May, 2024, 23:42
Quote from: DAVE BRADY on 12 May, 2024, 20:32
Hi,

Will you be taking it to the National Rally?  Keen to see one.

Dave.

Wotcha.

I could take it - OK, the clutch won't be ideal, but it will give you an idea of what they are like.
As far as starting the bike goes, it can't be faulted.
( Looks like the A65 is coming with me then ).
Title: Re: Arc Engineering Electric start
Post by: Lone Wolf on 16 May, 2024, 11:37
Quote from: DAVE BRADY on 12 May, 2024, 20:32
Hi,

Will you be taking it to the National Rally?  Keen to see one.

Dave.

Wotcha.

UPDATE - I've currently got the clutch off.  Riding the bike in stop-start traffic was nigh on impossible.
If I get the oil seal modification done in time, then I'll bring the A65.
Title: Re: Arc Engineering Electric start
Post by: DAVE BRADY on 16 May, 2024, 14:15
Hi,

OK.  Thanks for this.

Dave.
Title: Re: Arc Engineering Electric start
Post by: Allan G on 17 May, 2024, 14:00
Quote from: Lone Wolf on 16 May, 2024, 11:37
Quote from: DAVE BRADY on 12 May, 2024, 20:32
Hi,

Will you be taking it to the National Rally?  Keen to see one.

Dave.

Wotcha.

UPDATE - I've currently got the clutch off.  Riding the bike in stop-start traffic was nigh on impossible.
If I get the oil seal modification done in time, then I'll bring the A65.

When Ark first launched the clutch kit I asked they if they could make it comparable with a BNR belt drive as it was far superior to the poor clutch they are offering. They refused to budge and said their clutch would be more than adequate. So I decided I wouldn't have one.
Title: Re: Arc Engineering Electric start
Post by: Lone Wolf on 23 May, 2024, 00:23
Wotcha.

Well after much measuring, machining, welding and cussing  ;D I've made the clutch oil seal mounting.  It means the clutch works as it should, with no grab or snatch.  On the downside it leaked from where the starter motor fits . . . . so off it all came and a new one piece gasket was made and fitted.  So far the oil seems to be staying where it should.  I've yet to take the bike out on test, but that may happen tomorrow. ( weather permitting ).
So it looks like I will be taking the A65 to the open day this weekend.
Title: Re: Arc Engineering Electric start
Post by: Lone Wolf on 23 May, 2024, 00:26
Quote from: Allan G on 17 May, 2024, 14:00


When Ark first launched the clutch kit I asked they if they could make it comparable with a BNR belt drive as it was far superior to the poor clutch they are offering. They refused to budge and said their clutch would be more than adequate. So I decided I wouldn't have one.

Wotcha.

The advertising says "improves transmission" - well in my case it didn't - in fact it did exactly the opposite.  It made the clutch so grabby that the bike was a chore to ride.  Hopefully I've now sorted that out.  I intend to email Shropshire Classics and ask them what they suggest I do to make the clutch useable.  It will be interesting to see their reply.
Title: Re: Arc Engineering Electric start
Post by: DAVE BRADY on 23 May, 2024, 08:13
Hi,

As it is a belt drive I thought it would run dry with a sealed clutch bearing.

Dave.
Title: Re: Arc Engineering Electric start
Post by: Allan G on 23 May, 2024, 15:02
The clutch is a copy of the old Hayward type. I might be tempted to get one, then ask Bob Newby to make me a new basket for which to mount the ring gear.

However I beleive a couple of other BSA Specialists are also looking down this road.
Title: Re: Arc Engineering Electric start
Post by: EDDIE SIMPSON on 24 May, 2024, 00:35
what type of clutch comes with the kit , multiplate or diaphram?
a norton diaphram clutch could offer the best clutch settup but whatever type the grabbing is due to a over strong spring or springs is it not?
does the ark kit use a ballast resister to feed 6 volt coils like the commando?
Title: Re: Arc Engineering Electric start
Post by: Allan G on 24 May, 2024, 12:16
The clutch is a copy of the Tony Hayward clutch using the same inadequate 3 spring Cush drive unit. The BNR clutch is multiplate. But it is far superior in every way.

Not sure why the Norton comes with 6v coils. It shouldn't really matter as the electric boot is independent from the ignition system.
Title: Re: Arc Engineering Electric start
Post by: EDDIE SIMPSON on 25 May, 2024, 00:20
hi allen
i ve used gpz500 clutch springs in a 3 spring with surprisingly good results as their springs are good quality .
electric start triumphs and nortons used a ballast resister and six volt coils to aid cold morning ignition starts with a lower than 12 volt supply while the starter motor draws most of the amps from the battery at the same time.
i wonder whether any modern kit would run into cold morning non starts draining the battery too quick.
Title: Re: Arc Engineering Electric start
Post by: Allan G on 26 May, 2024, 09:03
Quote from: EDDIE SIMPSON on 25 May, 2024, 00:20
hi allen
i ve used gpz500 clutch springs in a 3 spring with surprisingly good results as their springs are good quality .
electric start triumphs and nortons used a ballast resister and six volt coils to aid cold morning ignition starts with a lower than 12 volt supply while the starter motor draws most of the amps from the battery at the same time.
i wonder whether any modern kit would run into cold morning non starts draining the battery too quick.

Makes sense. Is the ballast resistor bypassed during the cranking procedure? You could place the BR on the positive side of the coil, then have a relay connected to the temporary on (cranking) position on the switch to link the coil directly to positive side of the battery and bypass the ballast resistor.

I'm sure I read once that some older cars did this.
Title: Re: Arc Engineering Electric start
Post by: Lone Wolf on 26 May, 2024, 18:55
Quote from: EDDIE SIMPSON on 24 May, 2024, 00:35
what type of clutch comes with the kit , multiplate or diaphram?
a norton diaphram clutch could offer the best clutch settup but whatever type the grabbing is due to a over strong spring or springs is it not?
does the ark kit use a ballast resister to feed 6 volt coils like the commando?

Wotcha.

It runs the existing clutch plates in the new clutch drum - along with the existing three springs.

So you think it may be grabbing 'cos the springs are wound in too tight ?
I'll back the springs off until the clutch "just" starts to slip and see how that performs.
I'm wiling to try anything to get this clutch to work as it did before the electric start kit was fitted.

There's no ballast resistor fitted, but the starter works instantly every time with no hesitation in turning the engine over.  I can't falut the starting side of things - just this damn clutch.  I think a little bit more development work could have gone into this. For what it costs, you expect it to be perfect.
Title: Re: Arc Engineering Electric start
Post by: EDDIE SIMPSON on 27 May, 2024, 16:49
hi , nothing to lose by winding the springs out. as long as the starter turns the engine that would be near the mark.
the clutch springs may be too stiff . i have fitted standard gpz500 clutch springs before which were progressive and that bike has an electric start.
Title: Re: Arc Engineering Electric start
Post by: Lone Wolf on 28 May, 2024, 12:40
Quote from: EDDIE SIMPSON on 27 May, 2024, 16:49
hi , nothing to lose by winding the springs out. as long as the starter turns the engine that would be near the mark.

Wotcha.

The starter ring gear is on the outside of the clutch basket, making it in effect "primary kick" ( same as a Bantam ).
You could take all the clutch plates out and the engine will still start.

It's currently sitting in the "naughty corner" until I get back off my holidays.  I'm just not in the mood to take it all apart yet again.  Maybe I'll feel better about it in a couple of weeks.
Title: Re: Arc Engineering Electric start
Post by: EDDIE SIMPSON on 28 May, 2024, 16:38
some photos would be nice
Title: Re: Arc Engineering Electric start
Post by: HOWIE on 13 Jun, 2024, 23:22
OK late to this post and pardon my ignorance. Have both a Tony Hayward and an Arc electric start kit ready to fit to my Tbolt. The Tony Hayward belt drive kit came without a clutch centre and cush drive and ran on the BSA 3 spring clutch. The Arc electric start comes with a modified clutch centre running on a sealed bearing as runs dry. The clutch cush drive is a clone of the BSA / Triumph cush drive so why would this be inferior/inadequate?   
Title: Re: Arc Engineering Electric start
Post by: Allan G on 16 Jun, 2024, 10:21
The original 3 spring Cush drive needs to be in A1 condition for it to work well. It was by far inferior to the 4spring setup which proceeded it and where by the clutch hub was mounted integral to the basket to prevent twist and wobble.

If the Cush drive isn't in A1 condition and you have an engine which is capable of providing some good torque then the clutch will start to slip. The Triumph solution with the T140 was to fit heavier springs. Having tried the heavier springs on an A65, you need strong hands to work it.

The arc kit has the ring gear on the outboard side of the clutch. Personally I would rather have it at the back of the clutch to put the driven area in line with the bearing to prevent twist on the basket. However I understand that for simplicity and preventing modification to the crank case, it was fitted outboard.