While working on my PR7, I noticed a few things that i don’t like about it.

One of them – air filter box design! To be more precise – how the inside of it was designed!

Here is what i have noticed:

It has no decent water trap, even if intake sits very high by all standards! However, I think it should have at least a half decent area for water to collect, instead of running down straight to the throttle body.. and here is a picture that indicates that water does get in there, the worst part – all the sand and dust.

ajp pr7 air filter box water trap mod 7 — **Picture:** *dirt inside of the air filter box*

It has two very short tubes attached on both sides for water to collect, but they are way too short and out of sight in my opinion, and whenever they are filled up, the rest – will go straight down again.. By the way, my pr7 came with them missing! And that made me think- if someone who works on bikes day in day out can forget to put them back on, what’s the chance that i’ll remember about them?

When I split the air filter box, I noticed that there are no seals in between the two parts (top and bottom). I’m sure they do make a good seal once bolts and screws are tightened up, but.. i’m not planning to leave it like that!
Not the box – but Air filter cover! It has a very tiny gap for air to pass.. like super tiny! That tiny, that I can’t fit my fingers in! Looks very restrictive too!

Air filter cover micro gap for pr7 2 — **Picture:** *Air filter cover micro gap*

One more thing to mention, I’m not very happy with the crankcase breather leading nowhere.. 1. As soon as the bike is submerged into a deeper water it will suck that water in! 2. Unnecessary pollution.

I’ll talk about my solution to this in my next post.

WATER TRAP

My idea is simple, to create the barrier right in front of the existing one, as i’m sure that the original one is more for rigidity than anything else!

I will use:

5mm thickness plastic sheet that I used for my previous projects.
Dremel tool.
Epoxy resin.
White spirit – as a degreaser.

First thing, I cut a piece of plastic sheet to the size – Just big enough to raise the level, but not big enough to completely close the gap obviously – no higher than the bottom part of the air filter box. Also not wide enough to close the gaps on both sides where top and bottom parts interlocks. (Size around 173mm by 30mm)

Next. To prepare the surface for the epoxy to stick – used a dremel tool. All the smooth surface is nice and rough all around now, same with a part that will be glued in and all degreased with white spirit!

ajp pr7 air filter box water trap mod 3 — **Picture:** *ajp pr7 air filter box water trap mod*

And finally epoxy mixed up, and parts glued together! Beautiful!

Last bit to take care of, is the top part of the air filter box. Because I closed the gap at the bottom, obviously I’ll be restricting air flow, so to compensate for that, I’ll trim a bit of the top using a dremel tool!

Before i’ll put the air filter box together, I’ll do another 3 things. 1. To make sure there is some sort of seal between 2 parts i’ll use a non-setting silicone gasket in between them. 2. Ill coat all inside of the air filter box with fine coat of sticky grease to make sure that all the small particles have something to stick to and won’t get inside the engine (something I do with all air filter boxes). 3. Will make a port to attach crankcase breather box (i’ll talk about it in the next post)

“Hylomar Blue Gasket Marker” – non setting silicone gasket maker – something that I use a lot!

And here it is! Finished, sealed and greased air filter box!

WATER DRAIN TUBES.

I didn’t want to use original water drain tubes /traps, instead – I ordered a couple of meters of silicone tube (10mm ID, 14mm OD), 10mm T-piece hose joiner and 1 x 10mm hose end plug. Also used a few cable ties and a few clamps that I had – 2 for the air filter box, and 1 for the end plug.

Routed on the left side, joined them with a t-piece just above the rocker cover and left the end to hang right above the front sprocket! And that’s the end result! Love it!

AJP PR7 Air filter water drain tubes!QC — AJP PR7 Air filter water drain tubes!

AIR SCOOP, FILTER COVER

This is very easy as it’s actually two parts- cover and the barrier glued together. And it didn’t take a lot to crack the glue to thake that barrier out!

Again, using a dremel tool just trimmed a bit the middle part, leaving a bit more on the sides. And used a bit of the silicone to attach it back in place – something temporary, as i’m not sure if i want it in there at all!