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Starter relays

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italianmotor View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote italianmotor Quote  Post ReplyReply Direct Link To This Post Topic: Starter relays
    Posted: 29 Aug 2020 at 12:03
So on the V35, it has a Bendix type starter motor, so without solenoid like the later ones.

So would a new starter relay (black one) will do the same job as the old relay? Both are rated at 40 amps. The old relay may still work, haven't tested it yet.




Edited by italianmotor - 10 Sep 2020 at 18:29
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Dave P. View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 29 Aug 2020 at 13:15
I should think so.I recently replaced the original relay on the 850 GT with a Durite generic one. It works fine.
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Brian UK View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 29 Aug 2020 at 15:18
Are you sure there is no solenoid? The start relay is not capable of passing the starter motor current.
I must admit, I thought all the small blocks had the pre-engagement starter rather than a bendix. But a bendix motor also has a solenoid to switch the hunderd+ Amps involved.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 29 Aug 2020 at 16:07
As far as I can see by referring to Carl Allison's wiring diagrams all of the 350 models have a solenoid, as you would expect.
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

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italianmotor View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote italianmotor Quote  Post ReplyReply Direct Link To This Post Posted: 30 Aug 2020 at 10:13
Ah well Dave, I always go with original manual information where I can, this is from the V35 workshop manual, showing the non-solenoid starter, and the metal relay near it. The wiring diagram also shows this start in place. In the notes below the diagram, it actually says that the Bendix starter is not available as a spare part but will be replaced with the usual solenoid type. But obviously some bikes were fitted with them from the factory, including the one I have. In fact when I went to see it, I was telling the owner it was the wrong starter motor..
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Post Options Post Options   Thanks (0) Thanks(0)   Quote italianmotor Quote  Post ReplyReply Direct Link To This Post Posted: 30 Aug 2020 at 10:15
So the solenoid is tucked inside somewhere Brian?

Originally posted by Brian UK Brian UK wrote:

Are you sure there is no solenoid? The start relay is not capable of passing the starter motor current.
I must admit, I thought all the small blocks had the pre-engagement starter rather than a bendix. But a bendix motor also has a solenoid to switch the hunderd+ Amps involved.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 30 Aug 2020 at 12:31
I don't know, where does the heavy wire to the starter motor come from? Trace it back.
If it comes from that relay, then it will be a special one for very high current, so a modern replacement would not work - well not for more than half a dozen starts anyway.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 30 Aug 2020 at 12:36
Looking in the workshop manual, two starters are listed, one bendix type and one pre-engagement type.
The former is Bosch DG 12v 4HP
The latter Bosch DF 12v 7HP.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 30 Aug 2020 at 14:58
Point taken Adam. The wiring diagrams do all appear to show a solenoid so apparently not all of the diagrams are listed.
The arrangement shown in the drawing you posted looks much like the Laverda twin setup. No solenoid, but a 75amp relay instead.

https://www.laverda-paradies.de/shop/Bilder/Artikelbilder/9-42.jpg

Edited by Dave P. - 30 Aug 2020 at 15:01
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italianmotor View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote italianmotor Quote  Post ReplyReply Direct Link To This Post Posted: 30 Aug 2020 at 15:53
Thanks Dave. Here's the wiring diagram that shows the setup, the relay I have is same as on the left. I assume the switch in the starter motor is a solenoid then? Anyway, I will wire it all up as per the factory wiring diagram and see if it all works ok. If not, I might just find a used later starter motor, th0ugh this one does work.




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Post Options Post Options   Thanks (0) Thanks(0)   Quote Dave P. Quote  Post ReplyReply Direct Link To This Post Posted: 30 Aug 2020 at 16:33
I assumed (wrongly perhaps)that the switch shown inside the starter motor was a solenoid hence my initial post. Can someone qualified in these matters clarify please? Always happy to learn.

Perhaps the Nippon Denso on Laverda twins had a solenoid built in too; I never looked. They are a hefty .95 HP.

Edited by Dave P. - 30 Aug 2020 at 16:52
TO LIVE OUTSIDE THE LAW YOU MUST BE HONEST.

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Post Options Post Options   Thanks (0) Thanks(0)   Quote iansoady Quote  Post ReplyReply Direct Link To This Post Posted: 30 Aug 2020 at 17:10
As far as I'm concerned a solenoid is effectively a hefty relay (but often also moves something like the actuating mechanism for a pre-engaged starter).

We always used to call the thing that switched the current for Bendix starters a solenoid even though it was just a relay.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Brian UK Quote  Post ReplyReply Direct Link To This Post Posted: 30 Aug 2020 at 17:25
If the starter motor has two connections, one big terminal for the main battery wire and one smaller one for the relay output, then there is a solenoid contained in the starter.
If this is the case, then any 30 or 40 Amp modern relay will be fine.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote italianmotor Quote  Post ReplyReply Direct Link To This Post Posted: 01 Sep 2020 at 20:00

So I had some time to look at the relay today. I cleaned it up as best as I could, and checked it over with the multimeter, all connections seem sound. I connected up all the relevant wiring, and a charged battery, and tried to start the bike. The relay works, as in that it clicks, but the starter motor doesn’t turn. I checked with my meter and 12 volts aren’t getting across the contacts when the starter button is pushed. There is a spark between the contacts, seems quite bluish, a bit like when points have gone bad. What was odd though is when I had the + of my meter on the contact with the wire with white insulation on it, and the - connected to the crankcase, the starter motor turned fine - don’t know what’s going there though. So can I assume that maybe the contacts are worn and the current is just not getting across? Only way I can really tell is find another relay. Or another starter motor…any opinions?





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Post Options Post Options   Thanks (0) Thanks(0)   Quote Richard Hyatt Quote  Post ReplyReply Direct Link To This Post Posted: 01 Sep 2020 at 20:38
I can't quite see in the picture , but are the big heavy contacts eaten away?

Try this,
Put your meter on volts scale
1 clip on the big heavy connection directly from the battery.
1 clip on the big heavy wire that goes away to feed the starter motor. 
You should not show any volts at this point.
Then press the button to start the bike and see how many volts show up now.
Any more than 0.5 then you're losing it across these big contacts in the relay.
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