cali vintage under load

My cali vintage has recently developed a rough patch at 2100 to 2500 rpm in 5th gear and same revs uphills in 4th. The bike starts and ticks over perfect and revs perfect in all gears apart from that one small rev range. 95ron & 98ron petrol it is the same. Any suggestions welcome. Californhihay2014-06-26 20:33:58

I would run it at a minimum 3500 rpm in any gear. She is not a Harley!
All the best,

thanks, even at 2500RPM it is ok, I just dont want to have the rough spot if it is a wire or connector loose that will stop the bike running eventually or a air leak that causes lean running burns the valves or piston tops. If it is a known issue with low mileage due to the factory ECU being programmed for the emissions then I can live with it.

+1.The very nature of the Guzzi engine is that it prefers to rev.Whilst it will trundle along in 5th at 2500 rpm it is out of its comfort zone.

My Cali hydro was exactly the same; I had to keep the revs above 2500 if I wanted to avoid the rough patch, although I did enjoy trundling along at low revs occasionally. Having said that, the 1999 EV I just got is smooth throughout those low revs, and if your Vintage was as well, then perhaps that smoothness can be regained.

filled with 98ron petrol and did 150 miles in the peak district, after pushing all the relays and connectors to make sure none were loose. the bike ran smooth from tickover to yellow band on the rev counter in every gear. at 150 miles the rough spot came back just a little. i have taken off the tank it looks like it has just come out of the factory under the tank and fuel pipes. i have checked every connector under the tank and under the side covers, the side stand switch, air filter for rips or blockages. the throttle linkages are exact in sync mechanically. the outer plugs are like new, I could not check the inner ones, even with the tank off I could not get a box spanner onto the plug due to the head fins.
I checked all the rubbers on the injector bodies nipping up a little for luck. if it runs sweet for 150 miles before the rough patch at 2100-2500 comes back i will have to have a few of cups of tea before setting off on long trips that should have me stopping before the bike shows the fault.

Daft suggestion: could it be a blocked vent from your petrol tank? If so it would be cured by opening the filler cap and re-fitting it.
All the best,

thanks David, i will look today. I did 600 miles in the last week and another 450 planned for next week.
Graham, i had a cali special sport for 8 years before the vintage and that was smooth under acceleration too.
jobs to do list: tank breather, fuel solenoid & another look at the side stand switch. Californhihay2014-06-21 07:17:18

Topical subject as my Cali Hydro has similar problems at those engine revs, together with a vibration noise inside the fuel tank. The vibration got worse as the fuel level dropped. This was cured it seems by fitting extra zip ties on the pump/filter unit under warranty.Yesterday I removed the fuel pump unit and checked it. Found one zip tie had come off and the filter had moved slightly and was touching the mounting plate. There was a witness of rubbing. Fitted extra zip ties again.When I reassembled and checked for vibrating noise with engine running as I removed the filler cap there was a release of air pressure. Looked at the filler cap and blew throught the small hole in the side. This is small, but appears to be clear now. I checked that the rubber “drain” hose was clear that connects to the metal tube that is mounted centrally under the tank. Then got some spare tight fitting hose and tried to blow through the metal tube into the tank. This seems completely “blocked”. Is this supposed to be the tank breather, or is it a “water drain system” for any water trapped in the filler cap area? My BMW R100RT system is simply to drain water from the filler cap well and the tank breather is in the cap. How does a Cali tank breathe? That pipe is definitley blocked. What is the purpose of that tube and “drain hose”. Is there a one way valve in the tank? Any suggestions most welcome.

I believe this is a drain to clear (rain) water from around the fuel filler hole, if it’s blocked then the water will go into the tank with the petrol instead. Blocking up is a common problem apparently. Only going by what others have written here.

the vintage is now back to smooth under acceleration in all gears I checked so much stuff i have no idea what it was that cured the problem .
I have looked at the GUZZIDIAG software, has anyone used it with any success?
you just need two cables: OBD2 KKL 16 pin to USB cable with the FTDI and a Fiat 3 Pin to 16 pin Adapter Californhihay2014-06-21 21:16:09

Good result. Well done.

I think i will get the GUZZIDIAG or the Centurion-s diagnostic software to monitor the electronic gizzmos.
(all you have to do with electronics is keep the smoke from escaping, as soon as the smoke starts to leak out they stop working — how hard can that be)

Glad you have sorted it. Maybe you can add to the sum total of Guzzi knowledge if you do remember/ deduce what it was that did the trick!
All the best,