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Intermittent loss of power


czakky

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I believe relays can sometimes go bad a bit at a time. As evidence, my bike, early ownership days, before I was fully aware of the relay problems. Condition: I shut off after normal run - fail to restart. Thinking it must be the vapor lock scenario, I let it cool. Restarted after 10 min. All ok till weeks later, same deal, same result. Then I shut it off at a stop 20 min later and no restart... for 1 hour. After that restart it shut down mid-ride after about 5 min. It would not restart, period. Then I remembered something about relays. I swapped #1 with #5 and bingo. Instant start. At some point I had read to carry extra relays, so I had them with me. Not a problem since. GEI btw.

Seems to me this must have been the fuel pump relay failing gradually till finally giving up. Does this sound reasonable?

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Yeah, it could be. I have a thread from at least a year ago where I had a "groaning" fuel pump. Worked fine but she just made a slightly ugly sound when priming. Tach needle started the "St Vitus dance" a while back too. Of course I've switched relays around and all that but no change. Maybe I've got five baddies in there. Maybe my cleaner ignition switch will help. Time will tell...

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f you are going to do good / thorough troubleshooting , get a good test light and a good analog multi-meter. 

The test light needs no instructions but the analog meter requires knowing which terminal to plug your leads into and which scale to read.

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The grease goes hard like chewing gum and holds the contacts apart. When I first had trouble with mine it measured 18 Ohms, with fresh Vaseline back down to zero. We don't have as much trouble as other Guzzi owners that have the start relay powered through the ignition switch, it only takes 0.5 Ohms to stop one of those.

 

BTW it's easy to measure the ignition switch contacts because they are wired to points under the seat

The hot wire is connected to the load side (near side) of fuse 4

One of the contacts comes back to fuse 6 & 7 (near side)

The other switch contact goes to far side of relay 3 (30 contact)

 

Near side assumes you are standing on the left side of bike

If anyone wants a copy of my sketches send me a PM with your e mail address

 

BTW, don't leave the contacts dry, they will soon wear away if you do, the Vaseline lubricates the metal to metal contact point.

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Think I've licked this one. Pretty sure it was the ignition switch.

I put about 500 miles on and no loss of anything....

I've got fresh and new Omrons on now just for heck of it. Pretty sure the old relays were good but now I've got even more spares.

I even got my flashers to flash! (Bad blinker relay)

The old girl is pulling like a freight train!

Anyway thanks as always.

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The ignition switch is the weak point in many Guzzis, I don't believe the switch contacts were designed to take the 45+ Amps that the starter solenoid draws at the instant the relay contacts close.

 

I used to think all the spine frame bikes were immune from Startus Interuptus like my 2001 VII Sport but not so. the later VIIs suffer from the same stupidity, wiring the start relay through the ignition switch. It's pretty hard to get 45 Amps through all that spaghetti.

If you go on the other forum you will see most owners are familiar with the problem. I helped an old guy with a 750 Breva at the National in John Day over the weekend, while doing so two other owners came up and explained how they had done the fix. I was pleased to see when the bike refused to crank he knew exactly how to jumper the solenoid with a short piece of wire.

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I use Motorcraft electrical grease or tuner cleaner ( aerosol )  for these purposes. 

Changing gears.... What is your opinion of Stabilant 22a on electrical  connectors ?

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Sorry no experience with Stabilant 22a

I have only been using Vaseline for 55+ years, I'm sure there are better products but I don't feel the need.

When crimping or making a joint in a wet location I simply dip the wires in it, the grease repels the moisture and stops corrosion. I have also used regular grease or even oil if Vaseline is not handy.

Battery terminals should never be connected without something greasy.

 

 

Sent from my shoe phone!

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Anyone else used Stabilant 22a ? It is a connector conductivity enhancer . I use it on very low amperage connectors .

It looks very interesting. The claims made by the manufacturer ( http://www.stabilant.com/appnt20.php ) are so good that I wondered if it was another flavour of snake oil, but so far I can't find anything bad written about the stuff. One retailer claims that Hyundai and Volkswagen list it in service advice. It's claimed uses seem to be most effective on non sparking contacts so it may not offer any benefit on a V11 ignition switch. There is a similar product called DeoxIT.

I have not tried either product, and always assemble electrical connectors using lots of dielectic grease. So much that it oozes out of the connector as it is coupled so oxygen and water are excluded. Dow Corning Compound 4 electrical insulating grease is good. Vaseline is probably just as good, but I think Italian electrics need all the help you can give.

I believe that good electrical connections are made when plugs/pins/spades/bullets and mating sockets do not have any tarnish or corrosion on the contact surfaces. Bad connections can be fixed by unplugging and replugging, which scrapes off some tarnish. It seems to me that chemically removing an insulating layer of oxide is like introducing corrosion.

Can you share more about your experience? Is it good for long term exposure to road grime and vibration?

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It is for low current ( non sparking ) connections . I have used it for about 15 yrs. It is very pricey . A 15 ml bottle is from $60-90 .  

It is one of those things that must be good because you have not had troubles w/these connections.

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