Comments on: Change your Moto Guzzi California air filter

By: Dimi Pana

Dimi Pana — Sun, 29 Aug 2021 15:39:13 +0000

Hello, and thanks for making all this very helpful info available. I own a 2001 MG California Special (some call it Bassa ?!) with the original orange color (hence I call my Cali the “school bus”) lol!

I just managed yesterday to install the air filter by myself, the tank was about 1/2 full so at some point I needed my son’s help to hold the tank from tipping sideways, as I supported it at 45 degrees with a dowel wedged in the seat mechanism while the other (sharpened) edge was in the hole where the hex screws goes that holds the tank down.

All went fine (started the bike and it runs fine) but I have two questions and will not take the bike out for a long drive unless I confirm the following:

First, the old filter was a UFI and I bought the new filter from MG Cycles. They looked identical BUT the new filter was a pita to install. It kept sliding back and out of position as I was placing the upper part of the air filter over it and when I finally managed to do that the back bolts installed fine but the front one no matter how snug it left a small (about 1/8″) gap between upper and lower air filter housings, I could see the blue air filter gasket. I wiggled the cover and pressed in place, as best as I could without breaking anything, perhaps I narrowed the gap down to 1/16″ or maybe 3/32″ but it did not want to close all the way down. So I decided to …tape the gap all round the left, front and right side of the air filter assembly with …aluminum air duct tape. It doesn’t look that bad, but I am wonder why the gap?!

Second, I was working fast (not a good habit) and I am not sure of this: On the front of the tank, slightly to the right side there is an aluminum part that screws on the underside of the fuel tank. It has a thicker hose going to it from the bottom left side (which I did not remove during the air filter change) but it also has a nipple protruding to the upper front right with a much smaller diameter. Well, I do not remember removing a hose from that smaller nipple, and during reassembly I could not see any loose hose …waiting to be connected somewhere.

All the other connections (e.g. main fuel line, fuel supply “petcock” and low fuel gauge electrical plugs, the tank overflow hose, and a breather(?) hose vertical under the middle of tank) all were accounted for and back where each belongs.

Like I said bike starts, revs up, and idles fine but I am skeptical taking it out on a long ride unless I confirm that that small nipple coming from that aluminum part is NOT connected to anything?!

Thank you for your help!

By: Wolfram

Wolfram — Tue, 25 Aug 2015 11:12:16 +0000

Hi,
what might have happened is: the K&N permit more air through, and this doesn’t fit the map used by the injection system, causing the bike to run too lean. this might even out, if the “learn blocks” in the calibration permit enough deviation from the factory settings for the fuel injection to recalibrate itself using the oxygen sensor, if youve got one. thats why Harley says “injection need recalibrating”.

had a similar effect when doing this to an old MG, needed resetting the carbs. old times, then…

cheers
Wolfram

By: mike tiberio

mike tiberio — Wed, 11 Mar 2015 16:36:15 +0000

poor running after the initial install of a K&N air filter is not uncommon, especially if you over oil the unit. Take the bike out for a good flog to get the excess oil sucked out of the filter and burned up thru the motor, and your bike will be back to running fine. There are other reasons why I don’t like to use K&Ns, like the holes they develop over time that let unfiltered air through, but that is another story.

By: Randy Hooker

Randy Hooker — Tue, 09 Sep 2014 00:16:30 +0000

Hi John,
Thanks for all the great tips and insights.
Today I am on the Washingston State Olympic peninsula to do a 500 mile loop. Prior to this run I wanted to change the CalVin air filter.
I bought a K&N for a premium price and installed it two days ago. The bike immediately had trouble idling and stumbled terribly at 2K RPM.
So I assumed improper install, tore it down and reinstalled.
Same problem.
So I did it again. I am persistent.
Still bad.
Then I assumed it was a bad tank of gas after the filter change as I had dried it up prior to the install.
So I siphoned the tank and refilled. No good.
So I pulled the plugs to see if they were the culprit.
Perfect. But for 5 bucks I went ahead and replaced them.
No resolution..
So I fished the old filter out of the recycle bin and reinstalled it.
IMMEDIATELY all problems solved. Runs like a sewing machine.
I am convinced by this experience that the K&N, which uses an oil coating on the cotton fiber filter, actually restricts airflow compared to the UFI. Not a good thing!! Guess we should all stock up on UFIs

By: Bob Hadden

Bob Hadden — Tue, 09 Aug 2011 03:06:26 +0000

At around 9,000 miles my fuel line came off of the fuel pump on a road trip. Luckily for me I was able to contact Ace in St. Joe Missouri. He knew exactly what had happened(I didn’t) and drove 200+ miles to get me. At his shop we took the gas tank off and since we had the airbox exposed Ace suggested “tricking it out” with a KNN. He sawed off the snorkels and used a hole saw to let in more air to the box with 3 or 4 strategically placed holes. He also rerouted the fuel filter for easier access and replaced the “melted- by-gasohol” fuel line with submersible fuel hose. I immediately noticed improved mid-range with a nice induction sound (kind of like a 4-barrel kicking in) when I opened up the throttle. I have since replaced the catalytic converter (we can still do these things in Wyoming) with a Euro-spec cross-over I got from Ace and that beautiful Guzzi sound and mid-range got even sweeter (without being much louder) and no reprogramming was necessary. Call Ace Cycle in St Joseph Mo. He’ll hook you up.

By: Daniel Raidt

Daniel Raidt — Sun, 06 Mar 2011 16:18:47 +0000

You do not have to take the tank off to accomplish this, I just installed a K&N on my Cal Vin, Don’t disparage if the cover just doesn’t fall into place as the gasket on the K&N is slightly thicker but will compress when all the bolts are in place. Thanks for the write up, It gave me the inspiration to do this after having the filter for the past month or so.