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Author Topic: Dynastart- relay or no relay  (Read 394 times)

Rob vW

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Dynastart- relay or no relay
« on: November 01, 2020, 12:59:59 pm »
I would like to fit a dynastart instead of the standard dynamo, having recently experienced knee problems.

If I fit one with the correct regulator for a dynastart, do I still need to fit a starter relay?

Or, can I fit the dynastart and use the standard dynamo  regulator in conjunction with a starter relay?

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banquo

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Re: Dynastart- relay or no relay
« Reply #1 on: November 01, 2020, 11:24:05 pm »
I don't have one, but my understanding is that you need the special regulator, and also a smaller (edit) pulley to suit the Dynastart. TLM had one on eBay earlier this week
« Last Edit: March 31, 2022, 09:13:27 am by banquo »

Rob vW

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Re: Dynastart- relay or no relay
« Reply #2 on: November 02, 2020, 07:28:32 am »
I was wondering when you would respond Banquo!

Some of the posts I have seen suggest that you need the special regulator for the dynastart. However other posts suggest you can use the standard militare regulator in conjunction with a relay. Obviously if the latter is possible it will save me a bit of money.

Also, regarding the pulley, other posts suggest a smaller one for the dynastart. This is to get it spinning faster to generate enough power for charging the battery.

My understanding is that the standard pulley is 90mm diameter. The dynastart pulley is 70mm diameter. Getting a pulley sorted is not a problem at present (until lockdown begins on Thursday).

banquo

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Re: Dynastart- relay or no relay
« Reply #3 on: November 02, 2020, 10:12:56 am »
Yes, I've been a bit tardy of late. There's so little traffic on here I don't check every day.
I'm sorry, but I don't have any knowledge of how to wire with relay and stock regulator, but if others have practical experience of that, then as you say, it would be a far cheaper solution.
Smaller pully makes sense of course. I suspect my memory, as is so often the case these days, has let me down!  :(

Rob vW

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Re: Dynastart- relay or no relay
« Reply #4 on: November 02, 2020, 11:27:22 am »
I think I may have answered my own question by translating some of the Italian on a diagram of the relay & dynastart wiring.

The suggestion is that if you want to use a dynastart with the standard regulator for the Militare version, you need a relay.  The Lucas SRB 325 was specified. 

The regulator for the Civile already has "protection" or is already suitably rated to not need a relay.

I had to search round various posts regarding the pulley.  Modern pulleys are available with suitable taper lock bushes so that mounting on different spindles is not a problem.  I can source this and the shorter drive belt quite cheaply.

It looks like I'm going to be busy!

banquo

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Re: Dynastart- relay or no relay
« Reply #5 on: November 04, 2020, 09:58:04 am »
Well done Rob.
It's possible the Civile regulator is different?
A lot of the Civile came with Dynastart as standard, so maybe they used the same reg. for all?
I'm afraid it's well outside my scope of experience.
Would be good if you could post up details of the pulley. I know others have had problems sourcing one, and some are living with the stock one, and only charging at high rpm.
Good luck, and hope it all goes well

Rob vW

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Re: Dynastart pulley
« Reply #6 on: November 05, 2020, 09:10:10 am »
The dynastart pulley is dead easy to source.  There is no need to modify the existing pulley and this is why I personally think it is easier to restore old vehicles today.  And I cannot take credit for all of this because the answers were posted elsewhere on this forum.

The dynastart shaft is 17mm in diameter, whereas the original dynamo shaft is 15mm.

If you search online for a "taper lock bush", this will take you to any one of several companies supplying parts for power transmission.  A taper lock bush is a part designed to allow any size of pulley, including multi belt pulleys, to a shaft.  I did a search on one company website for a taper lock bush for a 17mm shaft and on the same company for a 71mm diameter pulley and SPZ637 v belt.  All these items have been mentioned on posts on this forum already. And don't be afraid to use the cast iron pulley.  These bikes weigh a ton already so a few more pounds doesn't make any difference.

The dynastart itself is no more than a dynamo with an extra set of components to turn it into a motor when required.

Again, all has been posted on this forum before.  However, you do not need the special regulator for the dynastart.  By wiring in a Lucas SRB325 solenoid/relay to the standard militare regulator you can operate a dynastart.  You just have to follow the instructions (translate from Italian) previously posted.  Mounting the Lucas relay is a challenge as it is quite large, but I will hide mine at the back of a side panel box to shorten the main cable runs.  The starter button will be on the right handlebar with power taken from the fuseboard and the 2nd wire to a terminal on the relay.

This is definitely not rocket science.  It just takes patience and time.

What with a halogen headlight, headlight relays, horn relay, indicators, LED tail/stop light and electric start, this bike is definitely not standard!
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banquo

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Re: Dynastart- relay or no relay
« Reply #7 on: November 05, 2020, 10:23:50 am »
Aye, everything's easy when you know how!
I didn't remember that all this had been covered before, but not remembering things is increasingly normal these days...  ::)
However, I'm delighted to hear that you found most of what you needed on here already, proving that although we might not have much traffic in these days of social media, a forum is far better for retaining and locating important information than Facebook will ever be.
Hope it all goes well for you.

monohorizontal

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Re: Dynamit-relais ou pas de relais
« Reply #8 on: November 05, 2020, 10:48:29 pm »
salut j'ai un régulateur avec relais intégré sur mon falcone bleu avec dynastar et un régulateur électronic seul avec un relais extérieur sur ma falcone sport rouge c'est comme ont veut et j'achète les courroies chez conrad  ;)
https://guzzi-nuovo-falcone.forumactif.com/t55-regulateur-electronique

hi I have a regulator with built-in relay on my blue falcone with dynastart and an electronic regulator alone with an outside relay on my red sport falcone. It's like have wanted and I buy the belts at conrad
« Last Edit: November 06, 2020, 01:25:55 pm by banquo »

plodder

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Re: Dynastart- relay or no relay
« Reply #9 on: February 14, 2021, 01:47:26 pm »
I know this is an old thread, but it was very useful to me in helping getting my old tractor electric starting.  Here is what I ended up doing.  I bought a HC-Cargo 110061 dynastarter.  The drive belt is a SPZ type, 10mm x 645mm.  Now the interesting subject of the pulley.  It is suggested that the correct size is 71mm.  I tried a 71mm pulley.  The starter worked but quite high revs were required for the charge light to go out (over 30mph on the road).  I have retained the original regulator which could have something to do with it.  I ended up with a 60mm pulley.  This gives better torque for the starter and the charge light extinguishes just above tickover.  I was a little worried about overrevving the dynastarter but I figure if the charge light goes out at the correct  revs all should be well.  I got my pulley from Bearing Shop UK (APZ060/1).  They will also machine it for you.  You need a 17mm bore and a 4mm keyway.  £32.99 all in.  As supplied, I found I could get the dynastarter shaft nut on but not the lockwasher.  There is always loktite of course but I prefer belt and braces.  I dont have a lathe but using a woodworking router at low speed with a sharp bit, I reduced the pulley boss by about 4mm to give room for the lockwasher. The original pulley had holes for a holding tool but I found I could tighten the nut well by using a strap wrench to hold it.  I saw the suggestion of using a taper lock pulley.  These are good devices (I used them extensively in a factory years ago) and I did try this solution.  However, I found there was not enough shaft length on the dynostarter for the taperlock to grip.  Yes, it would have worked but only gripping a short length of shaft.  I would not trust it.  On the electrical side, I used the Lucas SRB325 solenoid and a cheap handlebar push switch both of which worked well. I used car battery lead for the heavy solenoid connections and added a similarly heavy earth lead.  I did have a few problems which might have been to do with buying the dynastarter and leaving it on the shelf for 18 months before getting round to the job.  First off, it would not motor.  Ended up spinning it round on the kickstart with the starter button pressed (decompressor in of course) and eventually it got the idea.  Similarly it would not charge but that was not unexpected and was solved by flashing the unit in the time honoured fashion.  All in all a successful exercise and the starter works well, hot or cold. 

banquo

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Re: Dynastart- relay or no relay
« Reply #10 on: February 14, 2021, 03:07:37 pm »
That's a really helpful post Plodder. I don't see me ever fitting one, but I'm sure it will be some help to those who might  8)

banquo

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Re: Dynastart- relay or no relay
« Reply #11 on: March 31, 2022, 10:04:28 am »
I wish I had remembered that this thread was one here, having spent the past few days trying to fix the Dynastart on an ex-Police bike I picked up before lockdown, and which turned out to be in considerably worse condition than described. In a sulk, I pushed it away and pretended it wasn't there, until last year, when a minor issue with my other one forced me to pull it out. To cut a long story short, the Dynastart didn't work, and some minor investigation revealed that the belt was slipping, and too slack, even on maximum adjustment. Some more investigation revealed that the belt was too small to fit over the flywheel, but despite attacking the locking ring with my impact gun, it refused to loosen off, so I reverted to kickstart, and forgot about it again. This month, I was doing some more work, to replace the coil and condenser to try and resolve a persistent misfire at low rpm, and decided to have another go at the flywheel. This time I locked the flywheel using a standard G-clamp, bearing on the kickstart, with a sheet of lead flashing between for protection. The locking ring was already chewed up badly where someone had attacked it with a chisel, so I selected a blunt punch and with the flywheel locked, it came loose easily. Reversing the clamp to the front of the flywheel, and bearing onto the frame (lead sheet again) got the retaining nut loose, and bearing against the locking ring, drew the flywheel easily off it's taper, after I had given it a couple of sharp taps on the circumference to break the taper.
IMG_4557 by bancquo
Having forgotten the existence of this thread, I had to 'reinvent the wheel' and guess the smaller size of belt required. I went for 637mm (25") and a 10mm width cogged type (XPZ637).
IMG_4556 by bancquo
When I first put it on, I couldn't get it over my ;pulley, which is about 72mm outside diameter, even with the adjusting bolt removed. However, I discovered that the clutch cable, which is routed below the body of the Dynastart, was preventing it from lowering to the casing. After removing the cable, I managed to get the belt on, and job done. Next is to replace the hideous and dangerous solenoid that the previous owner had fitted below the tank, with exposed terminals, horrible wiring, and all tied up with an inner tube and tape... Also want to fit a fuse between battery and the main power lead, as of course there is no protection at all, and a short could lead to a fire. Does anyone know the maximum current drawn by the Dynastart? I read somewhere that they may be rated at 900W, so the maximum current would be about 75A?
« Last Edit: March 31, 2022, 10:08:56 am by banquo »