Rev counter, engine stutter, Cali' 3, carb model, Digiplex

Rev counter needle has decided to swing several hundred rpm up and down for the first few miles of the day. Then settles down as normal. Apart from assuming it’s about to die, is there anything that may cause this?

engine stutters briefly after a few hundred yards, then all is well. I’m going to drop the float bowls, see if there is any shit in there. Don’t see why this would only happen when cold, but, it’s an easy option.

Just found this on Guzzriders. org.

Cali III will have an electronic rev counter. It will be connected to one of the coil primaries.
Unfortunately they are not the most reliable instruments.

I removed all the relays, looked at terminals, wd40 in female terminal blocks.

Removed fuses, and put them back, after replacing the one which I assume is for the ignition ( when this fuse is out, there are no dash lights) it was a bit deformed by heat?

Undone any connector blocks behind the side panels, sprayed with WD40.

Undone the main earth, and whatever other earths were in the same place.

Rev counter no longer bouncing, the bike didn’t stutter after a few hundred yards.

Happy Bunny

1 Like

Found this on WilGuzzi

So what did it take to sort the misfire? We need to keep the knowledge base updated…


Chuck in (Elwood) Indiana/sometimes SoCal

87 AeroLario
95 Skorpion tour
“Two things are infinite: the universe and human stupidity; and I’m not sure about the universe.”
Albert Einstein

Offline jeffrey1212

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Re: relay to digiplex

« Reply #15 on: March 21, 2015, 07:03:04 AM »

put new ignition switch on first did not do it
took side stand relay out of circuit wired direct to digiplex relay did not do it
tightened up and cleaned contacts in digiplex relay and cleaned relay contacts and whoo hoo
now running like a Swiss watch

Played up again last night, 25 miles from home at 22:00. Removed seat, wiggled the Digiplex relay, got me home, PHEW.
This morning, I cleaned the arcing from the contacts, cleaned up the male connectors on the Digiplex relay.

Put back on the bike, started the engine, no erratic bouncing rev counter.

I also switched the ignition on, engine not running, I can see the relay working correctly ( obviously as it has just ran!)

Put the side stand down, Digiplex relay deenergised, as did, what I assume to be the side stand relay.
Side stand up and down several times, both relays working. The Kill switch is working as well, energises and deenergises the relays. Flicked it on and off several times to check its function.

Take it out later… locally![:rolleyes:]

Guy on the forum suggested these relays as replacements, if needed.

Bosch 0-332-207-307 & Siemens V23074. I searched, try finding one! too - their ref: 535-2558 - but on ‘back order’

Good luck!

This is the problem I had. The relays as suggested on Guzzitech, are not the same as mine.

Perhaps the info is out of date from Guzzitech.

I found various ones with differences in size and pins using those numbers.

Thanks anyway.

I popped the cover off this relay, removed one side of the contacts, removed some arcing marks, did the same on the fixed contact.

Time will tell…

My knowledge of Guzzis has come along, a little.

Power goes to ignition switch, then to the Kill switch, then to the side stand switch, then to the side stand relay, then to the Digiplex relay.

The horn relay is identical to the Digiplex relay. I’ve swapped them over. My thoughts are that as they are both dated 1992, the Digiplex one is on all the time the engine is running, the horn one is hardly used. Did this in case the relay is playing up.

I’ve had the ignition on, activated side stand to check the switch, that works, side stand relay works.

I may disconnect the side stand switch, as the side stand relay is of the normally closed type, which when energised by having the side stand down, cuts power to the Digiplex relay. This will at least move one item out of the intermittent engine stumbling / cutting out.

This may be boring to some of you, but, might be useful to someone.

I sprayed all the relay bases, fuse holders, and relay pins with contact cleaner.

Ridden it every day, so far, no bouncing rev counter, cutting out or stumbling.

Fingers crossed.

It’s not the horn relay that’s identical to the Digiplex, it’s the starter relay. Thought I should correct this.

Also note that the relay for the side stand is normally closed, so the circuit is complete with the side stand up. When down it is energised and becomes open, cutting power to the Digiplex relay.

This has caught me out before, when taking the bike out of winter hibernation. Side stand down, the engine will turn over, but not start.

As I’ve recently sorted a problem , I thought I’d pass this on.

With the side stand up, and the kill switch on run, when turning on the ignition, there is a very small momentary movement on the rev counter.

Either the side stand down, or the kill switch off, and the rev counter doesn’t move.

It’s just a visual indicator that the circuit is complete.

Might be useful if a Digiplex bike won’t start.