V7 sport quits and eventually restarts problem help

[coguzzi]

I've had this 74 V7 sport for 14 years (as well as a whole slew of other guzzi's) and this is the very first time she has ever given me trouble.

74 V7 sport with Dyna 111 electronic ignition (age/generation unknown as installed before me)

When i was on a ride recently i was just slowly moving thought traffic (accident) when bike died and no lights on dash at all. messed with it for a few minutes, rocked it back and forth in gear etc. Then suddenly dash came alive and she restarted like nothing wrong. did it 4 more times before i got home, if allowed to sit a minute would restart (3 times total) or if i just bump started it because i was still rolling (2 times). I seem to think maybe it was quitting when i used turn signal or brake light activated but couldnt verify by making it quit when i test that therory at home.

So, i suspect:
1. Dyna 111 ignition but have checked all connections and are good. havent done black box test i read in guzziology just yet.

2. Faulty ignition switch, its an updated ZADI not original known to be problem V7 sport switch, but cant make it act weird at home either. but in a few times in the past switch has not "woke up" dash when turned on

3. Maybe charging system fault. it is charging but forget #'s when i made sure it was charging, didnt seem very high to me (in upper 13 volts area). and battery is 7 years old but holding a charge just fine, again in the upper 12 volts which also seems low. I need to run through all the charging system test. Maybe the older battery is just barely adequate at accepting a charge from the charging system that itself is only barely adequate so im running out of power

any other ideas?

 

[john zibell]

After a search and read, do load test the battery. Next I suspect the ignition switch. Guzzi routes all power through the switch which can take out any switch over time. I've set up a couple bikes so that the ignition switch only activates relays that will carry all the current load.

 

[Amboman]

A faulty Dyna ignition wouldn't make you lose all power, only spark.

When was the last time you went through all of the electrical connections to make they're tight and clean? Especially on the terminal block just behind the steering head. 50 year old terminals lose their tension, a little corrosion can make a circuit go open, etc. If you have the original fuseblock, clean the fuse holders and make sure they hold the fuses tightly. I use my Dremel with wire brush to clean them. Fuses can get corrosion on their tips, so clean those as well (or replace with new ones).

 

[coguzzi]

A faulty Dyna ignition wouldn't make you lose all power, only spark.

When was the last time you went through all of the electrical connections to make they're tight and clean? Especially on the terminal block just behind the steering head. 50 year old terminals lose their tension, a little corrosion can make a circuit go open, etc. If you have the original fuseblock, clean the fuse holders and make sure they hold the fuses tightly. I use my Dremel with wire brush to clean them. Fuses can get corrosion on their tips, so clean those as well (or replace with new ones).

Ive gone through my wiring fairly recently (last year) as when i moved form Colorado to Quebec, Quebec made me install turn signals which my bike never had. That said, someone in the past has been in here and wiring is kind of a mess and has modern ATC/ATO blade fuses (which is better). I have a new wiring harness in mind if i have to put in a MGcycle order and pay the international shipping-ha. But i have been running through them as of yesterday, there are some grounds i am going to clean up.

 

[coguzzi]

After a search and read, do load test the battery. Next I suspect the ignition switch. Guzzi routes all power through the switch which can take out any switch over time. I've set up a couple bikes so that the ignition switch only activates relays that will carry all the current load.

so resting voltage on my battery: 12.7-12.9
ignition key on: 12.2
starter active: 10.2

That kind of says battery not passing home done load test with no fancy equipment to me, BUT starters in these bikes are quite large, soo..thoughts?

So far my charging system seems to be up to par
rotor windings: 3.0 ohm
stator brush: 4.2 ohm (higher than i was looking for)
stator winding between 3 yellow: .8-.9 ohm
output from what i remember was high 13's before i pulled fuel tank and havent hooked up my fuel bottle to run it right now

 

[john zibell]

Resistance between stator windings should be 0.62 ohms. Rotor windings across the slip rings 6.9 ohms +/- 10%. Be sure to lift brushes when checking the rotor slip rings.

 

[Amboman]

Ive gone through my wiring fairly recently (last year) as when i moved form Colorado to Quebec, Quebec made me install turn signals which my bike never had. That said, someone in the past has been in here and wiring is kind of a mess and has modern ATC/ATO blade fuses (which is better). I have a new wiring harness in mind if i have to put in a MGcycle order and pay the international shipping-ha. But i have been running through them as of yesterday, there are some grounds i am going to clean up.

The best harnesses money can buy are those from Gregory Bender. thisoldtractor.com/for_sale_wiring_harness_tonti_v7_sport.html

 

[coguzzi]

The best harnesses money can buy are those from Gregory Bender. thisoldtractor.com/for_sale_wiring_harness_tonti_v7_sport.html

agreed, have his harness in my Astore when i put it together from previous owners boxes of parts

 

[Mc Tool]

Do you know how to do a " Volt drop " test ?. A real good way to pin point poor connections , and there may be more than 1

 

[coguzzi]

Do you know how to do a " Volt drop " test ?. A real good way to pin point poor connections , and there may be more than 1

not sure, enlighten me please

 

[Moto-Uno]

Your "real" load test is pretty close to fine by me . The previous remark concerning stator resistance should read ~4 ohms , or that's what the 3 working ones I have here read , maybe just a typo . Are you in Quebec city ? Peter

 

[coguzzi]

Your "real" load test is pretty close to fine by me . The previous remark concerning stator resistance should read ~4 ohms , or that's what the 3 working ones I have here read , maybe just a typo . Are you in Quebec city ? Peter

i am in Quebec City for the last 6 years (wife is quebecois) but most of my life has been in Denver or WI/MN. had a short stint in Vancouver once though

 

[rhip]

i am in Quebec City for the last 6 years (wife is quebecois) but most of my life has been in Denver or WI/MN. had a short stint in Vancouver once though

My I ask when and where you got your Sport? You mention living in MN/WI. I'm in Minnesota, and my greatest regret is trading in my V7 Sport in 1985. The dealer told me that it was purchased by a guy from Wisconsin, and I've always wondered what happened to it. At the time, my main reason for letting it go was an electrical gremlin that blew fuses randomly but so often that I was eventually afraid to ride more than 30 miles from home. I carried a large box of those ceramic fuses, and lacked the skill or inclination to trace the problem.

 

[coguzzi]

My I ask when and where you got your Sport? You mention living in MN/WI. I'm in Minnesota, and my greatest regret is trading in my V7 Sport in 1985. The dealer told me that it was purchased by a guy from Wisconsin, and I've always wondered what happened to it. At the time, my main reason for letting it go was an electrical gremlin that blew fuses randomly but so often that I was eventually afraid to ride more than 30 miles from home. I carried a large box of those ceramic fuses, and lacked the skill or inclination to trace the problem.

HMMMM, what year was your sport? this is a 74 factory disc model that i think is a very low # production of (right around 100 if memory serves which it probably doesnt). I actually bought it in CO ironically close enough to where i lived i walked over with the $ and drove it home. BUT, this bike does have some Wisconsin histroy, owned by someone there. I was told maybe Gordon at MG Cycle had it for a while but he doesnt recall ever owning a V7 sport but has worked on a few, sooo who knows the real story. It would be fun if we could tie it back to you somehow. This is the one bike out of the 53 ive owned i said i would never sell so understand. Was Trackstar the dealer then? i remember them when i lived in MPLS from 89-97. And the 97 1100 sport i owned in CO came from Trackstar originally

 

[rhip]

HMMMM, what year was your sport? this is a 74 factory disc model that i think is a very low # production of (right around 100 if memory serves which it probably doesnt). I actually bought it in CO ironically close enough to where i lived i walked over with the $ and drove it home. BUT, this bike does have some Wisconsin histroy, owned by someone there. I was told maybe Gordon at MG Cycle had it for a while but he doesnt recall ever owning a V7 sport but has worked on a few, sooo who knows the real story. It would be fun if we could tie it back to you somehow. This is the one bike out of the 53 ive owned i said i would never sell so understand. Was Trackstar the dealer then? i remember them when i lived in MPLS from 89-97. And the 97 1100 sport i owned in CO came from Trackstar originally

Not my bike; mine was a '73. 4LS drum brake model. I bought it used from Leo's, and think the first owner was a woman who raced it with the CRA at Brainerd. I haven't owned 53 bikes, but have had a bunch since starting in 1966, and this one was still The One. I've got a 1250 GS that is likely the best all-around motorcycle ever made, but nothing was as rewarding to ride and own as that V7 Sport. Best of luck with yours!

 

[Dr. B.]

If you order a wiring harness from Greg Bender (thisoldtractor.com) you not only receive the harness but also a complete, and I mean complete (!) step-by-step set of detailed instructions explaining what connects to what. Each wire in the harness is color-coded according to the factory wiring diagram for the specific model; each wire will have the proper fitting/connector already attached or the fitting/connector will be included along with instructions detailing how it is to be attached to the specific wire; and you will be given Greg's business card that includes his telephone number which is your source of direct personal assistance. I had to re-wire a good portion of the electrical system on my 1978 850 Le Mans; Greg's wiring harness and assistance was instrumental in my ultimate success.

 

[coguzzi]

update, went ahead and replaced the battery since my current one was 7 years old but constantly on a tender. under starting load i am now reading mid 11 volts so much better. road test with intentional slow traffic riding did not recreate the problem so maybe fixed, BUT, my charging system still does not seem very strong (which ii know is not very strong in these bikes), at 3500rpm im at like 13.4volts, idle right around 12.7-9 as expected. So i will keep an eye on it and maybe do a charging system refresh in the futre

 

[john zibell]

If you have the mechanical VR, you can bend the tab to increase voltage, or pick up an after market adjustable VR.