Tonti: Air Filter

[Groover]

Has anyone used one of these air filters? And if so, does it make a difference in performance and/or worth the extra cost?

K&N Part# MG-0200


Also, when I first got my bike the rubber air box collector was cracked all over the place with big gaps and it seemed the bike was more lively than when I put the new rubber air box in.

This is the rubber air box collector boot (Part #17114350)


Now, I wonder... should I drill a few holes in the plastic air filter housing? was thinking maybe three holes inline at the bottom o o o.

This is the air filter housing (Part #17114050):


Finally... is there a trick to get the factory air housing assembly in and out? The way I do it is to remove it all in as one unit from the left side of the bike, twisting and turning, but it doesn't seem like a natural way of doing it (a lot of forcing).

In regards to the filter, I know there are some other options out there, but this time around I still want to keep the factory design in place. Maybe next year or so I'll change it all up!

[mtiberio]

K&N filters (and I'm running one on my Eldo), are no panacea. Clean a used one and hold it up to the light, you will see pin holes in the filter, pin holes that can let through dirt. When first oiled, they can choke a motor and cause it to run too rich. Once the excess oil gets sucked thru, and you get them to a stable configuration, that are fine. I like quiet bikes, and using the stock air box is a good way to maintain that. The paper elements can't be that expensive, perhaps you want to continue using them. That particular air box is one of the most sadistic pieces of italian engineering known to man. It was the factories way of giving the us epa the finger. It was the first epa/smog mandated guzzi aitr box (AFAIK).  If you have a way of removing it without smashing it, that that is the correct way. I assume you pull the left carb?

I'd leave it stock, with a stock paper element, but with a minor mod to prevent oil pumped out the breather box from entering the intake. To do that you put a hose on the output of the breather box (sometimes you have to cut off the "T" to make a single exit). Run that hose out the bottom of the boot (you slightly enlarge the drain hole). Do this and you will not leave a smoke screen after you chop the throttle after a long hard run on the highway...

[Groover]

Great reply, thanks you. I had to look up the meaning of "panacea", but I got it now! I will definitely stick with the original filter then. The oil issue you mentioned... isn't that what that drain nipple is for (shown on the rubber collector)? If that's not it, I may need a little more details on that mod.

In regards to the removal of the assembly, yes I do remove the left carb.

Thanks again for the detailed reply.

[mtiberio]

yes, you show a picture of the rubber boot and its oil drain, but not the breather box that sits inside. there were two version of the breather box, one with a simple metal tube that vented oil into the filtered air side of the air filter and then later they brazed/welded a "T" onto the end of that breather (same effect however, oil into the intake). the problem with the breather is it is a bit small in interior volume (they had to fit it inside the air box). so it tends to pump a bit of oil. when the oil comes out the tube, it is supposed to get sucked into the motor and burned (clean, epa style) which can result in a smoke screen behind the bike, carboned valves, pistons, etc. any oil not sucked and burned will pool on the bottom of the rubber boot and make its way out the drain as you suggest. What I'm suggesting is you run a tube from the box outlet directly to and out the drain so the motor doesn't burn this oil and you can drip it onto the ground.

[mtiberio]

what you see here is the early version without the T attached, but you see where you would attach a hose if you wanted to positively route expelled oil of out the air box.

[Groover]

Ok, got it now. Pipe that so it goes straight out the nipple instead of pooling up in the rubber to then maybe drain on its own (which I noticed it doesn't very well as a bunch of oil just dripped when I removed the air box assembly).

Thanks for the follow-up with image.