Laverda SF 0

I bought the bike brand new in 71 and within 2 years the starter exploded because I accidentally hit the starter button when shifting down from 7000rpm - Cost me $900 as I could only order a starter from the Breganzie factory.

Really wish you Guys would LISTEN ;o)
 
Motoddrob: Apparently you are not hearing me as there was an issue with the early 1970/71 Breganzie 750 SF wiring regarding the grounding of the Starter Relay. And if you are playing with them OLD circuits today be aware.
 
Motoddrob: Then tell us how to FIX that early circuit to prevent from destroying the Starter Clutch and possibly the Starter motor.

Maybe because Canada got 200 Special SFO's as an early introduction to the 750 SFC and Austrialis did not ;o)
 
Why Not - I could always do it after that FIX as long as I did not accidentally hit the Starter button ;o)

Gearing down from 7000+ nearing 8000rpm is nothing with a 1970 Breganzie 750 SFO (Hey they came with Velocity Cones and No Air Filters)
 
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The 70 SFO and the SFC which followed where basically the same bike except for Carbs, Cam, Rear Sets and Skin - Both had the same Cylinder head and compression. The SFC did get needle bearings on the crank.
 
Laverda SF said:
Dellortoman - Have you ever owned a 1970 Breganzie Laverda 750 SF !!!

It is a specific wiring fault with them foot ball (rugger ball for you Aussies) Bosch head lamps.
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No, I never have owned a 750SF, but I don't have to own one to know how it works. And it has nothing to go with the headlamp shell, football shaped or otherwise. The 750 starting system is similar to the triples, and pretty much every other electric start motorcycle in existence.

The whole point of a sprag type starter clutch is that it can turn the engine over to start it, but it CAN'T be back-driven by the engine and spin the starter up to astronomical revs. It's a disconnect between engine and starter system. As soon as the engine fires, the starter clutch disengages. No amount of pushing the starter button while the engine is running will get it to re-engage.

The only scenario that can explain your starter failure at 8000rpm is that the starter clutch seized for some reason, most likely un-related to the starter motor being energised. Probably something to do with poor lubrication and the high revs you subjected it to.

I don't care if you never change your belief, and I suspect you never will. I only write this to counter your incorrect advice to other owners. You're encouraging people to make an un-necessary (and bothersome) modification to their electrical system.
 
Dellortoman said:
The whole point of a sprag type starter clutch is that it can turn the engine over to start it, but it CAN'T be back-driven by the engine and spin the starter up to astronomical revs. It's a disconnect between engine and starter system. As soon as the engine fires, the starter clutch disengages. No amount of pushing the starter button while the engine is running will get it to re-engage.
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In exactly the same way as a freewheel on a bicycle. If you are rolling fast downhill and "accidentally" pedal forwards, it shouldn't engage and spin the pedals smashing, your legs to bits.
 
motoddrob said:
Ron your just one of thousands of owners that have/do own 750s and you seem the only one to have had a problem with your starter clutch blowing the starter motor. If it was an issue why hasn't there been thousands of starters blown. I have owned 4 SF models over the last 47 years and never had that problem and yes I've hit the starter many times while the engine was running. You failed to service your starter clutch when it need it and the results was a blown starter. Your myth has been debunked by many owners and experts.
And how many kms did you do on your 750? I bet no where near the hundreds of thousands many 750 owners have done on their 750s me included.
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There have been thousands of starters blown. Just you try and find one. Worth a lot on the market I can tell you.
I blew a starter motor on my SFC when on a damp morning the freewheel was making those nice whirring noises. Bike was started towed behind my friend Jacquelines Guzzi California combination. The insides of the starter motor resembled a smoothie fresh from the liquidiser after that.

Paul
 
Sounds like you better take Ron's advice then Paul.
In all of my 750 experience going back to 1974 I've never known of a blown starter motor by hitting the starter button while the engine is running.
Come to think of it i can't remember hearing of a blown starter from any of my mates that have owned 750s and there are many from the 70s.
Hands up all those that have
 
motoddrob said:
Sounds like you better take Ron's advice then Paul.
In all of my 750 experience going back to 1974 I've never known of a blown starter motor by hitting the starter button while the engine is running.
Come to think of it i can't remember hearing of a blown starter from any of my mates that have owned 750s and there are many from the 70s.
Hands up all those that have
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If the engine fires with a stuck freewheel, the starter is in orbit. That's what happened with my SFC when I towed it, that's what will happen if you push start a bike with a jammed freewheel. Just look at the number of starter motors on offer and the number of people looking for one.

Quite a few of the 19..... 750s made have blown their starters and keep on doing so. Nothing to do with hitting the starter button with the engine running but all to do with freewheel maintenance and that is often overlooked. Leave a 750 with an unhealthy freewheel out on a misty night and you may well have a problem in the morning. ( Particularly an SFC if you haven't taped up the dynamo belt cover. A must do if you park the bike in the rain or damp)

Paul
 
Well thats what I've alway said
It relates to a starter clutch issue. Still, i cant remember of any blown motors amongst any of my mates 750s and thats quite a few over the last 47 years. Even my SFC has spent many nights/days parked/ridden in the rain when travelling and the starter has never been serviced in the 40 years that I've owned it. It spent months chained to a fence outside a bed sit in Earls Court after we arrived from North America before i brought a van to park it in leading into winter. Have serviced the starter clutch a couple of times though. Its done 29000 miles, probably more than most SFCs have done in their life.
 
motoddrob said:
Well thats what I've alway said
It relates to a starter clutch issue. Still, i cant remember of any blown motors amongst any of my mates 750s and thats quite a few over the last 47 years. Even my SFC has spent many nights/days parked/ridden in the rain when travelling and the starter has never been serviced in the 40 years that I've owned it. It spent months chained to a fence outside a bed sit in Earls Court after we arrived from North America before i brought a van to park it in leading into winter. Have serviced the starter clutch a couple of times though. Its done 29000 miles, probably more than most SFCs have done in their life.
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You've always said that and so have I. I'm just adding that there's a hell of a lot of liquidised starters out there and no spares.

Paul
 
"The 70 SFO and the SFC which followed where basically the same bike except for Carbs, Cam, Rear Sets and Skin - Both had the same Cylinder head and compression. The SFC did get needle bearings on the crank."

come on Marnix get started on this one perleeeeeze
CLEM
 
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