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V85TT Air Box Lid Mod

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Below is what we recommend doing to the stock air box lid for those installing our GTM Fuel Kit.

Stock air box lid show below, with two small pieces of tape removed to expose the two rectangular slots in the OEM Guzzi lid.

257954C7-5CB7-4587-8637-0B4081FCB7BF.jpeg

The stock lid and filter showed (our fine Southwest talcum powder) dust leakage patterns inside the lid.

0F47AA2C-A6C3-4D3D-B998-512938BE9915.jpeg

You can remove the lid entirely over the filter as we did in the dyno thread, or poke it full of holes however you’d like. Start by removing the snorkels. We cut/extended the slots, and added two more as shown. Then a 2” hole (could be 3~4 1” holes too) in the upper portion. Next one we do will be on the top facing upwards. Shown with a superior fitting K&N Filter.

42DF1A7A-7D41-4FC3-A03F-2F9C3CB50AEE.jpeg
F0D238FA-C36D-4D7A-8001-B5272D242750.jpeg
 
Interesting that dust apparently got past the paper filter. I have a BMW F650 (single cylinder) that drew enough vacuum to pull the paper filter part way into the air box and allow unfiltered air into the intake when it was almost new. Fortunately, I found it before riding in dust so there was no apparent damage. I cleaned the interior of the air box and installed a K&N filter. The performance difference was amazing with no other changes. The K&N has much more filter area than the OEM paper and a better sealing surface so there has been no sign of dust getting past the filter since it was installed.

After my experience with the BMW and seeing Todd's photos, I am probably going to get a K&N for the V85TT soon. I am guessing I can run the K&N with everything else stock as long as I don't cut extra openings in the air box.
 
GerryAZ said:
Interesting that dust apparently got past the paper filter. I have a BMW F650 (single cylinder) that drew enough vacuum to pull the paper filter part way into the air box and allow unfiltered air into the intake when it was almost new. Fortunately, I found it before riding in dust so there was no apparent damage. I cleaned the interior of the air box and installed a K&N filter. The performance difference was amazing with no other changes. The K&N has much more filter area than the OEM paper and a better sealing surface so there has been no sign of dust getting past the filter since it was installed.
After my experience with the BMW and seeing Todd's photos, I am probably going to get a K&N for the V85TT soon. I am guessing I can run the K&N with everything else stock as long as I don't cut extra openings in the air box.
Click to expand...
For sure, quite a shock to me. Thanks for your post and experience Gerry. Funny, there's more OEM-only folks (especially in the BMW world it seems) that think it's paper filter or die. Good to see someone else who benefited from oiled gauze filters. When I dirt-track raced as a kid, I saw (and cleaned up after) most of the filter styles. Paper was OK, but very restrictive as to flow on the dyno. Foam was worthless, even when oiled properly IME. Oiled gauze was tops, and a pre-charger sock even better for silty or heavy wet dirt.
I've been enjoying the benefits of these for decades.
I sell both the K&N and DNA filters on the online STORE tab above, and I try to be competitive pricing wise (outside of Amazon). BMC was very good as to sizing and silicone rubber fit/seal, but they've been increasingly more difficult to get, so K&N it is. DNA is the next in line, as I really like what they did with the deep V7 filter I sell on the Store as well.
Fueling is a different story. Like every Guzzi I've fueled over the last 20+ years now, they really come alive when allowed to ingest some fuel, even bone stock. Add air, and the data is very different. So up to you on running it. ;)
 
Is item below in your store the correct K&N for my 2021 V85TT? I have had very good service from K&N filters on many vehicles over the years so I will buy a genuine K&N for my new bike. I will consider fueling modifications if a programmer becomes available for the ECU in my Centenario, but have never needed to make changes on fuel injected vehicles. I generally had to adjust carburetors on other vehicles to compensate for the improved air flow and filtration. I learned soon after installing K&N filters in my R1150RS and F650 to not talk about K&N at BMW gatherings or on user forums. I also found foam filters to be less than ideal on the dirt bikes I rode growing up on a farm.

gtmotocycles.com

K&N Filter - Griso - NTX - Cal 1400 - V85TT

K&N Filter for your Griso, Stelvio NTX, California 1400 or V85TT This filter offers a SUPERIOR fit compared to the OEM element, providing no leakage around the edges of the lid like the stock filter does. Washable, reusable High-Flow Air Filters™ feature a state-of-the-art design of layered...
gtmotocycles.com gtmotocycles.com
 
GerryAZ said:
Is item below in your store the correct K&N for my 2021 V85TT?
Click to expand...
That is correct...

gtmotocycles.com

K&N Filter - Griso - NTX - Cal 1400 - V85TT

K&N Filter for your Griso, Stelvio NTX, California 1400 or V85TT This filter offers a SUPERIOR fit compared to the OEM element, providing no leakage around the edges of the lid like the stock filter does. Washable, reusable High-Flow Air Filters™ feature a state-of-the-art design of layered...
gtmotocycles.com gtmotocycles.com

It's noted twice in the description and shown in a model search.
You haven't lived unless you've twisted the grip on a fuel-corrected bike. All I'll add as 25+ years of doing it has exhausted me in talking about it.
 
Reminds what I used to do to air box's back when motocross bikes were air cooled. You might want to add a pre-filter call outwears; outerwears.com - they make pre-filters for K&N. Or you could do what we did back in the day and just wrap your filter in a
panty hose.
 
After confirming that 2021 takes the same filter as earlier years, I just placed an order for a K&N filter from the GTM store. I will be checking for distortion/leaks in the air box lid and also watch for future fueling modifications that are compatible with the 2021 engine management system.
 
I have by lid off now and dust appears to be leaking in from the two holes right above the throttle body. I quickly wiped them off and out before I took this picture but notice the dust still remaining further in. IMO whatever hoses or fittings attach on the other side of those holes are allowing dusty air to leak in on the filtered side.

 
Those four bolts secure the air box to the throttle body. I think the residue you see is from dust getting past the sealing surfaces of the air filter.
 
Thanks yes I want to add grease to where it mates and at the large O-ring in my image. Might even replace it with a slightly thicker O-ring.
 
The yellow frame shows the area where the plastic of part 2B007979 should have been thicker. The material is so thin that it even deforms. A seal to the filter can be interrupted here.

I have used a BMC filter now which seem to fit and seal better.

If you closely look a this image of the K&N filter:
gtmotocycles.com

K&N Filter - Griso - NTX - Cal 1400 - V85TT

K&N Filter for your Griso, Stelvio NTX, California 1400 or V85TT This filter offers a SUPERIOR fit compared to the OEM element, providing no leakage around the edges of the lid like the stock filter does. Washable, reusable High-Flow Air Filters™ feature a state-of-the-art design of layered...
gtmotocycles.com gtmotocycles.com
it seems that there is a groove which could solve this problem with the sealing.
Could somebody investigate who has a K&N filter?

airbox.jpg20230623_155458.jpgkn.jpg
 
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I serviced my air cleaner and I found a potential problem with the air cleaner, the 5 screw clamp that holds the air cleaner to the removable housing needs reworking, the screw holes are too tight! (The screws should slide through these holes so the clamp pulls up tight against the filter) they don’t and there is a possibility that dust will leak between the filter where it meets the housing.
This should be checked before traveling on the dirt.
 
I just got my 2022 V85 June 8th 2024, used with 2600 miles on it. The owner bought it last year and road it a mix of street and gravel/forest roads; though don't know how many. I already have 5300 miles on it now, mostly street riding. I have taken it on gravel roads and a month ago I did some of the MABDR with a friend. With that said, most of my riding is paved roads.

A few weeks ago I learned of the unfortunate news that the airbox sucks, which has me concerned. I checked mine tonight and sure enough there was some dust. Not a ton, but dust has made it through the airbox seam. I cleaned both halves of the airbox out with glass cleaner and alcohol, and lightly wiped out the intake velocity stack. There was a light amount of dust in the inlet and around the butterfly valve. There was no oil in the airbox.

What are the chances I've done any mild or moderate damage to the engine?

I have read that the V85TT can use some oil. in the almost 3000 miles I've point on the bike, I've put about 12 ounces of oil in it. I keep it around the halfway point of the sight glass, as it seems to settle there like others have noticed. I'm hoping this amount can be considered somewhat normal for an air cooled v-twin. I live in Virginia so I've ridden it in some hot weather the past couple of months, so I don't know if that can play a roll. The bike runs and rides great. I had asked how the original owner how he broke it in. He said he took it easy, but I rode it hard as soon as I got it to get the pistons and cylinders under pressure.

My plans for the airbox:

1) I have a new Australian Uni Filter, oiled foam filter ready to go in. The Uni Filter has a much thicker seal and weighs about 5 times as much as the oem filter. It's a substantial filter.

2) I used black gorilla tape to seal up the slots in the removable half of the airbox.

3) I have Bel-Ray waterproof grease I'm going to use as filter sealant. I'm also going to cut strips of some paper shop towel lightly coated with the grease, folded in half, and used as a gasket material between the two airbox halves. There is no seal at the moment. My wife also thought that the thin foam pad used in toolbox or kitchen drawers could be cut to match the airbox, and be used as a gasket. Not a bad idea.

4) I'm doing my next oil change ASAP. Not that it matters and I'm not trying to start an oil controversy, but I plan on using Maxima Maxum4 Extra 10w60 with the factory oil filter. I figure if there is some dirt in the oil/engine, an oil change is better sooner than later.

So, what are the chances I've did any real damage to the engine?

What do you think of my ideas to hopefully solve or mitigate the dust intake issue?

Thanks
 
I just looked at the parts sheet for the V85, and there seems to be a seal for the two halves of the airbox. My airbox does not have this seal and I'm wondering if others are missing it also. There is nothing between the tongue-and-groove of the two airbox halves. If this is the case, I wonder if this is why people have unfiltered air making it's way into the engine.

Here's the part number for the seal: AP8120615

Screenshot_20240827_220053_Drive.jpgScreenshot_20240827_220118_Drive.jpg
 
It is a thin seal that seats deep in the groove so it is not obvious. It actually comes as a long piece that you cut to length and glue the ends together. There are two locations where that gasket material is used (see item 1in two locations in the exploded parts views). The unfiltered air gets past the sealing surface of the factory paper filter, not past the gaskets identified as item 1. K&N filters (and other some other aftermarket brands) have better sealing surfaces.
 
GerryAZ said:
It is a thin seal that seats deep in the groove so it is not obvious. It actually comes as a long piece that you cut to length and glue the ends together. There are two locations where that gasket material is used (see item 1in two locations in the exploded parts views). The unfiltered air gets past the sealing surface of the factory paper filter, not past the gaskets identified as item 1. K&N filters (and other some other aftermarket brands) have better sealing surfaces.
Click to expand...
I see the seal now. It was hard to notice and feel. I had read and watched videos that the oem filter didn't seal well, but then also thought there wasn't a seal where the two halves met. I'll still dab some waterproof grease along the tongue-and-groove to ensure a good seal. The seal for the Uni Filter seems to be much larger than the OEM filter, but I don't know how it compares to K&N or other options. Maybe I'll post some pictures of them side by side for comparison.
 
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