Starter self-engages w/motor running (TONTI)

[Baldini]

6am in the dark riding at a steady 70mph or so on my way to a trackday on Tonti I hear a whine, & feel vibration. Pulled over thinking it was something gone in trans but couldn't find anything obviously wrong. Pressed starter - nothing! Ah! Figured I could still do the track day bumping it, I was running late so left as it was. It ran fine then later did same again. I disconnected power from the starter motor & left it, & it ran good all day.

 

Can anyone suggest most likely diagnosis/fix from symptoms described? I have basic knowledge of system & figure it's bad relay, switch or solenoid, but what order/how to check? Thanks.

 

KB

[pete roper]

The earth for the starter relay, (not the solenoid.) goes through the switch/button. If the switchgear is a bit 'How's Yer Father?' the trigger wire from the relay may just be rubbing against the handlebar and then earthing out through the head bearings, (It's how the factory did it on Mk I Lemans's! ) Otherwise look for the wire to the switch/button and trace the loom back to see if it's worn or frayed anywhere and its allowing the circuit to earth.

 

Not a good idea to run the starter motor engaged with the engine running. It not only means that the motor works as a generator but the armature brushes were never meant to take the armature spinning at 18,000+ RPM. It gets messy very quickly!

 

Pete

[Tracey]

I had a similar problem with my Convert. After some head scratching and cursing I tracked it back to a short in the head light beazel. The problematic conector block grounded out to the beazel causing the starter to engage constantly. If I remember correctly, the top two wires outboard in the connector block.

 

Just a suggestion, I'm no expert!

 

[Baldini]

Thanks.

 

Wiring/switch & layout etc is all non std but in principal same as Guzzi set up.

 

Had a look at it - the relay is not functioning. The solenoid is not functioning. Motor spins the gear but doesn't move it forward to engage ring gear, this when I short it between terminals. Switch looks OK. Dunno the sequence of events but these bits are knackered. Wiring looks OK.

 

I have a spare Bosch starter.

 

Does the Valeo (V11 type) fit as straight replacement? - it looks like it would, & is much lighter.

 

KB

[El_Gringo]

I can't comment on compatibilities, but if you need spares for the valeo starter, try ............

 

Wood Auto Supplies Ltd

Cromwell Works

Colne Road

Huddersfield

HD1 3ES

United Kingdom

 

Head Office:

Telephone: 01484 428261

Fax: 01484 434933

Email: sales@woodauto.co.uk

 

UK Sales:

Telephone: 01484 439000

Freefax: 0800 137012

 

I got a new starter body c/w magnets £11 + VAT they had all the other parts, solenoid, leaver brushes etc as well.

[pete roper]

Well, first thing I'd do is make sure you're getting trigger current to the relay, then the solenoid. The relay is a typical cheapshit thing, just bin it and stick on a modern one.

 

For the bendix to throw out and push the pinion into engagement the solenoid has to work. As the solenoid pulls in it pulls a yoke forward tht pushes the bendix mechanism forward and engages the pinion in the ring gear. These have been known to break but in this case I think it's probably a relay issue. Try simply getting a piece of wire and jumping from the batter + to the trigger spade on the solenoid. If it spins up nicely then the problem has to be the relay.

 

'Pete

[Baldini]

... relay is a typical cheapshit thing, just bin it and stick on a modern one....

 

Tested relay - it's f8888d. Tested solenoid it's also f8888d. But I don't think they did so bad - been working 30yrs!

 

Replacement relay arrived today from Guzzi shop: it's a sodding great old fashioned looking metal cased thng more than double the size & wt of the original soddin great old fashioned looking metal cased thing. I dunno why. Think I'll send it back. Any recommendations what/where to get good quality small replacement in UK? Can I use V11 type?

 

I have spare Bosch starter, but is V11 type Valeo a straight replacement fit? It looks the same.

 

Thanks for help.

 

Cheers, KB

[pete roper]

Yup, the valeo starter motor is a D6RA or some such, they aren't cheap but the bolt straight on. As for a relay? Go to Halfords and buy yer standard 25 amp shitox plastic 4 pinner relay, should cost you about a quid! If you haven't done so already run a direct feed to the delivery side from the battery rather than having the jump wire that has already been up and down the bike half a dozen times delivr a few tired electrons to the solenoid

 

Pete