Breva 750 Starter Problems

[The_Happy_Drunk]

G'day,

My Breva has been going great since I replaced the battery and use a battery saver, but recently something is up with the starter, well, I expect the starter.

When I try to start, some times it's as if I have a flat battery and the motor just manages to turn over, other times it will turn over almost as good as new. For awhile I could here a noise while using the starter motor which reminded me of the sound that a clutch throw-out bearing makes when it needs replacing. I've checked the leads to the starter motor, battery and relays, and all seem clean and tight. The battery has full charge and is less then a year old.
A friend suggested that he had a similar problem which was caused by the relay. I swapped the relay with one of the others and it did seem to make a slight improvement but the problem is still there.

Has anyone heard or witnessed this? And besides putting the starter motor in for a reconditioning, is there any other areas I could look at? Mst of the times the motor starts, but soimething isn't right.

Cheers
Leon

 

[ghezzi]

According to my mechanic and his diagnostic equipment, my battery to engine "earth lead" has too much whatsomy thingies resistance or something. :?:

It looks perfect to the naked eye but the "machine" says different. :?

 

[Rafael]

Hi Leon

Have you checked for a loose battery cable? Cleaned cable ends? Check voltage on the battery and the voltage drop when starting. Can't remember the min. voltage during a load test, but 12v seems to make sense.

I have a Valeo starter that sat on the shelf for years because it stopped working. After reading some Valeo rebuild articles I started tearing it down then decided to test the starter again after blowing it out with compressed air and voila! - it worked. Rebuilt it and it's in my B11 now.

Have you read this thread in the BNS12 section of the Forum? [/url]https://www.guzzitech.com/forum/188/7448.html[/url]

It has links to other threads on the same subject.

 

[The_Happy_Drunk]

Thanks for the replies,

I have ckecked for loose and dirty connections, but I will recheck particulary the earth. The only think I haven't checked is the voltage drop, I don't believe this to be the problem as it's not consistent enough and the battery is fairly new. Having said that, I will check tomorrow.
I will also followup the other thread you showed,

Cheers

 

[sign216]

Dear Drunk,
I've got a couple of ideas.
1) The modern 750s have a battery ground on the right side of the engine. Look for the heavy battery wire from the neg terminal, going to a bolt on the right side of the engine case. Mine showed corrosion early on, and this is an easy ground to miss. I don't recall the date this was added, so it's possible your Breva doesn't have it.

2) The starter button on the handlebar can be a problem, because sometimes it gets corrosion and adds resistance to the circuit. The starter button also carries the full current for the solenoid, instead of using a relay, so that's another issue. You might try cleaning the switch (if you can get into it) or try a modification. There's two different modifications;
a) Add a relay to the circuit, to give the solenoid a direct feed from the battery. One of the American Guzzi places sells this drop-in modification. When I did a DIY version of this it added only 0.25 volt to the total current, but some people swear by it.
b) Modify the existing circuit to put in a direct battery feed. Pat Hayes posted this modification here on Guzzitech, and also on Wild Guzzi. This does the same thing as suggestion a), but it's a different method to do it.

3) Open the starter and solenoid for inspection, cleaning, and service. Because these starters are used on many different brands, there's postings on the net for this. It can be work to do this, but it can't hurt to take a look.

The Yahoo group for 750s has the above modifications and starter repair guides. Look at the Links page and the Files page. http://autos.groups.yahoo.com/group/MG_750/
Also, try searching Guzzitech past messages, or other Guzzi groups. You should find postings on all these ideas.

Let us know how it works out.
Joe

 

[kiwi dave]

This intermittent starting symptom is typical where the voltage drop through the wiring and ignition switch is preventing the solenoid from operating. Why it is intermittent I'm not sure, but your situation is similar to one I had with a 1200 Sport.

If you haven't already, check out https://www.guzzitech.com/forum/160/4908.html Modern "No Start" issue solution.

The first diagram is for a small block. There's a wealth of information in these seven pages.

 

[john zibell]

2) The starter button on the handlebar can be a problem, because sometimes it gets corrosion and adds resistance to the circuit. The starter button also carries the full current for the solenoid, instead of using a relay,

Sign216,

Take a look at this schematic https://www.guzzitech.com/attachments/ ... _Breva.gif item 36

 

[sign216]

Exactly. The starter switch, item 29, is carrying the full battery current.

 

[john zibell]

Exactly. The starter switch, item 29, is carrying the full battery current.

Look again, item 29 is the ignition switch. Item 32 is the RH switch assembly. The starter button energizes relay 36 which them provides voltage to the starter solenoid. Are we looking at the same schematic?

 

[sign216]

Look John, I am here to help Leon with his no-start problem, not to argue about wire diagrams.

If you don't like my explanation of the circuit setup, then take a look at Kiwi Dave's post. His link shows the Pat Hayes answer to the problem that I referred to in 2)b of my post.

 

[john zibell]

Look John, I am here to help Leon with his no-start problem, not to argue about wire diagrams.

If you don't like my explanation of the circuit setup, then take a look at Kiwi Dave's post. His link shows the Pat Hayes answer to the problem that I referred to in 2)b of my post.

Yes,

Pat's solution is to provide a separate, fused, 12 volt supply to the relay that energies the solenoid. I've done that modification to several bikes.

 

[Holt]

Look John, I am here to help Leon with his no-start problem, not to argue about wire diagrams.

If you don't like my explanation of the circuit setup, then take a look at Kiwi Dave's post. His link shows the Pat Hayes answer to the problem that I referred to in 2)b of my post.

Yes,

Pat's solution is to provide a separate, fused, 12 volt supply to the relay that energies the solenoid. I've done that modification to several bikes.

And THAT is exactly why I'm wondering about that solution. The current over the relay coil couldn't possbile be so high, that it would justify a separate feed. Never understood the mod.

Sorry if I interfere with the discussion :dry:

I installed a separate ground bar and wired with a 6 mm2 (9 AWG) to a suitable point on the block, as shown, to ensure proper grounding, as the OEM wires are a bit, errh, delicate, in my opinion. Never any grounding problems here.

 

[john zibell]

Holt,

The problem is that the 12 volt supply to the relay also supplies so many other components, and that the wire is, in my opinion, too light a gauge that available voltage is diminished. By isolating the starter relay supplied voltage from the other components you don't get the resultant voltage drop that can inhibit performance. Needless to say though making sure available grounds a clean and sufficient as you have done is also a good thing.

 

[kiwi dave]

And THAT is exactly why I'm wondering about that solution. The current over the relay coil couldn't possbile be so high, that it would justify a separate feed. Never understood the mod.

Hello Holt

The current isn't for the relay coil, but for the relay contacts which feed the starter solenoid. Others on this forum have measured up to 20 amps, despite the circuit being protected by a 15 amp fuse.

I too was originally skeptical, but now swear by the modification.

 

[sign216]

I did a version of the modification (there are several ways to go about it) but only got a 0.25 volt increase.
There is approx. 9.5 volt passing through. It is doing the job fine, but am interested in what others have.

 

[Holt]

I've forgot exactly how that mod was done; know there is a scheme somewhere out there. But where is that?
At a fast look on Carl Allisons splendid scheme, it doesn't seem to be at difficult mod to make, if the solenoid feed over the contactor breakers are fed separately, so far so good.
OTOH I still cannot see that the other consumers on the present feed are of a significant magnitude. This mod may perhaps be meant for older models with an analogue starting procedure?

 

[kiwi dave]

I've forgot exactly how that mod was done; know there is a scheme somewhere out there. But where is that?

Try the link in my first post https://www.guzzitech.com/forum/160/4908.html