'81 V50 III electric question

[Guest jeffco]

I'm working on this bike for someone, they said it wouldn't start out of the blue one day.

 

They also said there was a fuse that blew at the same time. Fuse was replaced, but it made no difference.

 

So today when I got a chance to have a look, I found that everything seems normal, except nothing happens when you hit the start button. I jumped the solenoid with a screwdriver and forced it to crank, it fired right up and ran.

 

I saw there were two relays of the same type on the left side, one that went to the solenoid so I swapped it with the other (headlight relay, maybe?), no change. So I assume that's not it either. Took the tank off and chased the wires up to the switch, uplugged the connector and sprayed with WD-40 for good measure, checked for chafed areas etc...nothing. Tried moving the harness around while holding the start button, nothing.

 

I assume the start button switch went bad, but what I wanted to ask is this:

 

Is there any type of nuetral safety interlock on this bike? I didn't see one that was real obvious, they are usually pretty easy to find on Jap bikes...that's a common cause of no-crank on them, the switch sticks and it thinks you are trying to start it in gear. Am I correct to assume this bike doesn't have that feature?

 

Also...we noticed one fuse was quite warm with the ignition on....and they said it was NOT the fuse that they changed...there is only four fuses, but we had no reference as to what it protects. Looking at the fusebox from the right side, it was the 3rd fuse from the left, if that helps.

 

This concerned me because the last time I saw that, it was a reg/rectifier that was bad and caused a wiring meltdown...still...not sure if it's related, a red herring, or what.

 

Anyway...didn't mean to write a novel about it, but this (Guzzi) is uncharted territory for me, and just wanted some orientation and knowlegeable opinion before diving in blind.

 

Thanks!

[Guest Gary Cheek]

If you have a stuck starter solenoid it could cause the solenoid's circuit to draw excessive current. The fuse holders and relay socket contacts on the V50 are also sources of many cranking woes. ( I take it CRANKING is the problem?) Give everything a good cleaning, check out the starter solenoid etc. If that doesn't work you can send me a PM as there are a few other places to look. Rather than using the Sport forum perhaps email is preferred?

[drjim99]

I'm working on this bike for someone, they said it wouldn't start out of the blue one day.

 

They also said there was a fuse that blew at the same time. Fuse was replaced, but it made no difference.

 

So today when I got a chance to have a look, I found that everything seems normal, except nothing happens when you hit the start button. I jumped the solenoid with a screwdriver and forced it to crank, it fired right up and ran.

 

I saw there were two relays of the same type on the left side, one that went to the solenoid so I swapped it with the other (headlight relay, maybe?), no change. So I assume that's not it either. Took the tank off and chased the wires up to the switch, uplugged the connector and sprayed with WD-40 for good measure, checked for chafed areas etc...nothing. Tried moving the harness around while holding the start button, nothing.

 

I assume the start button switch went bad, but what I wanted to ask is this:

 

Is there any type of nuetral safety interlock on this bike? I didn't see one that was real obvious, they are usually pretty easy to find on Jap bikes...that's a common cause of no-crank on them, the switch sticks and it thinks you are trying to start it in gear. Am I correct to assume this bike doesn't have that feature?

 

Also...we noticed one fuse was quite warm with the ignition on....and they said it was NOT the fuse that they changed...there is only four fuses, but we had no reference as to what it protects. Looking at the fusebox from the right side, it was the 3rd fuse from the left, if that helps.

 

This concerned me because the last time I saw that, it was a reg/rectifier that was bad and caused a wiring meltdown...still...not sure if it's related, a red herring, or what.

 

Anyway...didn't mean to write a novel about it, but this (Guzzi) is uncharted territory for me, and just wanted some orientation and knowlegeable opinion before diving in blind.

 

Thanks!

 

The handlebar switch gear on these bikes was pure junk. The Right Hand starter switch on my 1984 V65 fell apart after one year. The preferred fix at the time was to replace the Guzzi switch with one from a Ducati Pantah. The Ducati switch was really well made but had one big quirk - it was wired backwards. In other words, when the switch was in the "Run" position it was actually "Stop". The switch had to be in the Stop position in order to start the bike. Needless to say I often forgot about this "feature" when I had not used the bike in a while and would go through hours of useless troubleshooting trying to start the bike with the switch in the wrong (i.e., "run") position.

 

Bottom line - make sure this bike does not have a Ducati starter switch in place of the Moto Guzzi switch. The Moto Guzzi switch is multi-colored, while the Ducati switch is all black.

 

Good luck!

 

Jim

[Guest jeffco]

The handlebar switch gear on these bikes was pure junk. The Right Hand starter switch on my 1984 V65 fell apart after one year. The preferred fix at the time was to replace the Guzzi switch with one from a Ducati Pantah. The Ducati switch was really well made but had one big quirk - it was wired backwards. In other words, when the switch was in the "Run" position it was actually "Stop". The switch had to be in the Stop position in order to start the bike. Needless to say I often forgot about this "feature" when I had not used the bike in a while and would go through hours of useless troubleshooting trying to start the bike with the switch in the wrong (i.e., "run") position.

 

Bottom line - make sure this bike does not have a Ducati starter switch in place of the Moto Guzzi switch. The Moto Guzzi switch is multi-colored, while the Ducati switch is all black.

 

Good luck!

 

Jim

 

OK, that helps a lot, thanks!

 

But do you know if there is a neutral interlock on the starter circuit? I wanted to take the switch pod apart and have a look inside, but ran out of time and didn't see a glaringly obvious way of taking it off the bar...

[Guest jeffco]

If you have a stuck starter solenoid it could cause the solenoid's circuit to draw excessive current. The fuse holders and relay socket contacts on the V50 are also sources of many cranking woes. ( I take it CRANKING is the problem?) Give everything a good cleaning, check out the starter solenoid etc. If that doesn't work you can send me a PM as there are a few other places to look. Rather than using the Sport forum perhaps email is preferred?

 

 

Like I said, I pulled the connections apart in the harness, and at the relay, shot them with WD even though they looked good, swapped relays to no avail, then manually engaged the solenoid by crossing the terminals at the starter, and the starter cranked fine, and the engine started and ran fine. The problem is there is just no reaction when you press the start switch.

 

I didn't think about it at the time, but I should have tried shunting the wires for the start switch at the harness connector and see if I could crank it that way...that would have verified it was the switch that was the problem. I'll try that and let you know. I'm hoping that the excessive load is somehow related to the contacts falling apart in the switch, that would be really nice.

 

But without any idea what is on the circuit for that fuse, it's hard to tell...

[Daniel Cooper]

Is there any type of nuetral safety interlock on this bike? I didn't see one that was real obvious, they are usually pretty easy to find on Jap bikes...that's a common cause of no-crank on them, the switch sticks and it thinks you are trying to start it in gear. Am I correct to assume this bike doesn't have that feature?

 

Also...we noticed one fuse was quite warm with the ignition on....and they said it was NOT the fuse that they changed...there is only four fuses, but we had no reference as to what it protects. Looking at the fusebox from the right side, it was the 3rd fuse from the left, if that helps.

 

This concerned me because the last time I saw that, it was a reg/rectifier that was bad and caused a wiring meltdown...still...not sure if it's related, a red herring, or what.

 

Anyway...didn't mean to write a novel about it, but this (Guzzi) is uncharted territory for me, and just wanted some orientation and knowlegeable opinion before diving in blind.

 

Thanks!

 

 

On a 1981 V-50 ?? Are you kidding ? There is no neutral interlock.

[Guest Rocker]

I'm working on this bike for someone, they said it wouldn't start out of the blue one day.

 

They also said there was a fuse that blew at the same time. Fuse was replaced, but it made no difference.

 

So today when I got a chance to have a look, I found that everything seems normal, except nothing happens when you hit the start button. I jumped the solenoid with a screwdriver and forced it to crank, it fired right up and ran.

 

I saw there were two relays of the same type on the left side, one that went to the solenoid so I swapped it with the other (headlight relay, maybe?), no change. So I assume that's not it either. Took the tank off and chased the wires up to the switch, uplugged the connector and sprayed with WD-40 for good measure, checked for chafed areas etc...nothing. Tried moving the harness around while holding the start button, nothing.

 

I assume the start button switch went bad, but what I wanted to ask is this:

 

Is there any type of nuetral safety interlock on this bike? I didn't see one that was real obvious, they are usually pretty easy to find on Jap bikes...that's a common cause of no-crank on them, the switch sticks and it thinks you are trying to start it in gear. Am I correct to assume this bike doesn't have that feature?

 

Also...we noticed one fuse was quite warm with the ignition on....and they said it was NOT the fuse that they changed...there is only four fuses, but we had no reference as to what it protects. Looking at the fusebox from the right side, it was the 3rd fuse from the left, if that helps.

 

This concerned me because the last time I saw that, it was a reg/rectifier that was bad and caused a wiring meltdown...still...not sure if it's related, a red herring, or what.

 

Anyway...didn't mean to write a novel about it, but this (Guzzi) is uncharted territory for me, and just wanted some orientation and knowlegeable opinion before diving in blind.

 

Thanks!

[mike wilson]

Do the small-block-starter-relay-fix.

 

http://www.guzzitech.com/SmallBlockRelay-PHayes.html

 

The colours might be different but the principle is the same on all of them. It was the best 30 minutes maintenance I've ever done on an electrical system.

 

On a severely problematic one, you may have to replace the original wiring too.