Jota Starter 120° / Bosch 0 001 160 003

a contact once came off the Bosch starter relay on TOG and the starter was constantly turning and the engine running at the same time, I killed the motor and the starter still ran, and still turned the motor, so whipped of a side panel, and disconected the battery, that stopped the bugger, to get home, I reconnected the battery, with ignition already switched to on, engine started, side panel in tank bag and rode home, over 20 miles, the starter turning all the time, it never engaged the motor (other than the initial start) and I got home just fine, on killing the motor it contiued to turn, until the battery was disconnected again, the follpowing day I discovered the price of a Bosch relay (around 80GBP I recall) and bought one for almost any British car, Mini, Land Rover. metro, Jaguar etc, fitted it under the battery tray and have never looked bacK,
The cost was about 10GBP and it is a proper 400amp moving iron solenoid, rather than an 80 amp relay, lasted twenty years and then bought another WHICH WAS CHEAPER!
Clem
 
Blimey Clem. I think I would have simply disconnected the big cable at the starter motor (or at the battery end if it's separate from the other +12V connections). You still could have started the bike by momentarily dabbing it onto its terminal bolt.
Was your starter motor cooked after all that continuous running?

Easy to say in hindsight I suppose. Not being there at the time.
 
no tools Cam, disconnection was made by removing a massive inline fuse, a good idea (so I thought) at instalation time (now gone), and on reinsertion it of course fired up, the starter survived but remember it was running under "no load" conditions, what surprised me is that the sprag survived as well, weird feeling killing the motor only for it to continue turning.
CLEM
 
If the engine turns quicker than the starter, the clutch will not engage and can spin on forever without damage. The starter can get a bit hot under the collar if it is forced to run for an extended time, but should survive OK.

Things go terribly wrong only when the clutch jams for some reason.

piet
 
Just to confirm, when I bought my Jota 120 it had a Bosch starter motor fitted.
I am also inclined to think that was how they all were and that the SJCE starter appeared with the RGS around 1983.
 
Piet: It's SAFER to wire the Starter Button which energizes the Starter Solenoid to ground through the Transmission Neutral switch if you do not have a Clutch Lever Safety SX - Believe me.

Breganzie fixed that issue sometime around 71/72 with their bikes by incorporating a Clutch Lever Switch.

For that matter North America mandated a Clutch Start Switch for all cars with manual transmissions in 71.
 
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Breganzie fixed that issue sometime around 71/72 with their bikes by incorporating a Clutch Lever Switch.

Not on Oz delivered bike they didn't, nor the 2 750s I brought in the USA or the 1200 I brought in the UK.

How many people here have blown their starter by hitting the starter button while riding????
You'd have to have a problem with your starter clutch for it to happen.
The concept of having to select neutral to start your bike would really give me the shits, especially if it stalled while sitting at the front of traffic at a set of lights.
 
motoddrob said:
The concept of having to select neutral to start your bike would really give me the shits, especially if it stalled while sitting at the front of traffic at a set of lights.
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Couldn't have said it better myself. :)
I've also had to ride home with a busted clutch cable. Easiest way to get going at a couple of sets of traffic lights (slightly up-hill) was to stop the engine, put it in first gear then hit the starter button.
 
Doug Homes old bike now owned by Marty has a big red start button in the middle of the dash, or did, I think Marty has gone back to std, anyway when I rode it and it didn't idle for a good while when cold, I am murdering these sentences, if it stalled when cold in traffic you had to put it in neutral to reach that start button with your left hand and rev it a bit to keep it going then pull the clutch and get a gear. You have no idea what a pain it is to not keep your hand on the throttle and still use your thumb on the go button, not exactly as Ron says but modding the standard setup and getting a worse practical situation is painful.
 
Vince said:
Doug Homes old bike now owned by Marty has a big red start button in the middle of the dash, or did, I think Marty has gone back to std, anyway when I rode it and it didn't idle for a good while when cold, I am murdering these sentences, if it stalled when cold in traffic you had to put it in neutral to reach that start button with your left hand and rev it a bit to keep it going then pull the clutch and get a gear. You have no idea what a pain it is to not keep your hand on the throttle and still use your thumb on the go button, not exactly as Ron says but modding the standard setup and getting a worse practical situation is painful.
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I rode that too Vince, biggest pain is the arse, Marty has sorted now but (y)
 
I find starter buttons all over the place on custom wannabee cafe racers. Stupidist place is behind and below the carbs, 3 hands required to work the choke, throttle and button. Built by Tasmanians? I mean, if they've already got 2 heads... ;)

Ron, in over 40 years of riding these bikes I have never experienced anything like you describe. I've had slipping starter clutches, but never jammed ones. I've seen several outcomes of this situation, makes me wonder how deplorable the condition of these bikes must have been to cause such mayhem.

piet
 
sfcpiet said:
I mean, if they've already got 2 heads... ;)
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Oi, I resemble that comment. :)

When I first got my Jota, the original starter button was fucked so the PO had installed a separate starter button on a handlebar mounting on the far side of the brake M/C mount. With the right hand on the throttle grip, it was too far away to reach with the right thumb - even for a Tasmanian. :)

Not quite as stupid as your example Piet, but basically meant that I had to reach across with my left hand to press the starter button while giving it a bit of throttle with the right. One of the first things I did after buying the bike was to fix the original starter button. I figured it was easier than having my thumb surgically extended.
 
I would also go bonkers trying to deal with a bike that had to be in neutral to start the effing thing!!

I don't blame you for modding your starting circuit Ron, because as we know the results of a trashed ND starter are very hard on the bank balance, but your panic was misplaced and you unfortunately didn't actually determine the real cause of the malfunction. In 45 years of working personally and professionally on Laverdas I've never seen one that suffered a catastrophe for the reason you give. Not sure we;ll ever cvonvince you though ...

As for awkward ergonomics, I always like to have all buttons and switches within easy reach of both hands.
 
We all should go back to kick start bikes, these electric starts are the work of the Devil. They will fail and you will rule the day kickstarts went away. Kick starters can be fixed on the side of the road, I always carry a spare kick lever for when not if the evel electric start fails. Its fun to kick start a stalled bike at traffic lights, who cares about all that horn honking when its so much pleasure kicking away.
 
Ron, you're like an old record stuck in a groove - always harping on about wiring the starter via the neutral switch.
And you're old enough to know what a Bakelite 78 record is.
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Dellorto - Apparently you have never owned say a 69 750S or a 70 /71 SF.

If the rivets get loose holding the back plate on the starter clutch - Guaranteed it will lock up and engage the starter it you accidentally hit the starter button at Hi-Revs - As I say the Breganzie factory started using the Clutch SX around mid 72/73 so you could only start the bike with the clutch Lever engaged - But I choose to use the Neutral switch to ground the Starter Solenoid because my Lucas Bar switches and levers did not have that Safety Clutch Lever Switch. TEST it yourself ;o)

I really like Lucas Switches on my bars because they are ergonomic, rugged, easy to maintain and clean and thumb controlled were you never have to remove your hands off the bars but they have a fatal flaw - Especially if the back plate on the Starter Clutch is loose due to them stupid rivets.

My starter exploded because the Lucas Bar Controls did not have a Clutch Safety Switch in conjunction with them crappy rivets holding the back plate on the flywheel - That's why after an expensive repair which included the price of a new starter that I elected to ground the start relay through the transmission neutral switch and it worked, although I could only start the bike in neutral, After that I kept that starter for over 40 years even if I inadvertently hit the starter button at 7000 rpm.

Like you intend to hit the Hi-Beam-Dip but you accidentally hit the Starter button.

If you don't understand that your the with the problem ;o)
 
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My starter motor blew up. Reckon the sprag clutch jammed causing the starter motor to spin at very high revs and the centrifugal force blowing the motor apart. In normal operation the crank's centrifugal force forces the rollers out so there is no mechanical contact between the crank and starter assembly. Anyway that's my take on what happens.
 
Laverda SF said:
Dellorto - Apparently you have never owned say a 69 750S or a 70 /71 SF.

If the rivets get loose holding the back plate on the starter clutch - Guaranteed it will lock up and engage the starter it you accidentally hit the starter button at Hi-Revs

If you don't understand that your the with the problem ;o)
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I think you might have just nailed it, Ron - if your sprag clutch rivets were dodgy it will definitely explain why hitting the starter may have caused the catastrophic failure you speak of. On a healthy sprag hitting the starter will have ZERO effect.
 
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