If I use an FCR-Foam Air Filter Sock, will it be okay to use it in the rain?

If I use an FCR-Foam Air Filter Sock, will it be okay to use it in the rain?

This is about the Foam Air Filter Sock for the CBX1000. I remember writing an article before asking, "Is it okay to ride without an air filter even in the rain?"
I'll write my conclusion first.
As long as you apply filter oil, it's fine.

↓This is a previous article↓
In the case of a racing carburetor such as FCR, can it be run in the rain with a Velocity Stack specification? Should I do it?

As I wrote in the link above, I don't like to ride in the rain.
This is a story about what happens when it suddenly rains.
This article may be about the rainy season, but
I recently had to deal with filters, so I'm writing this on a whim.
Motorcycle air filters are:
① Air cleaner box (standard type)
② Air filterless (Velocity Stack only)
③ Power filter (wire mesh wrapped around filter paper)
④ Sponge filter (sponge)
This time, I'm mainly talking about sponge filter ④.
[It's fine if you apply filter oil.]
I said above, but that doesn't mean it's absolutely fine.
At least, I don't understand the point of riding in the rain with an FCR or something like that.
*Races and the like are excluded.
This story is based on the assumption that filter oil is applied.
In the case of my CBX1000, I don't use power filter ③,
so this article doesn't apply to it, but it's roughly the same.
I'm writing this assuming that it's a Foam Air Filter Sock.
So, let's get started!

The term Foam Air Filter Sock

I should state this up front, but the Foam Air Filter Sock mentioned in this blog post
refers to air filters made by RAMAIR.
When my other blog posts write RAMAIR, in their case they are referring to Foam Air Filter Sock.
It can also refer to engine intake systems, such as ram air intakes.
Thank you for your understanding.

You can tell by cleaning the filter

If you try cleaning the Foam Air Filter Sock, you will see that
when it is sufficiently soaked with filter oil, it will repel water.
At this point, it is safe to drive in the rain.
Of course, there is a limit to the waterproofing effect as filter oil will drip along with the rain.
As long as it is not in a position where it will come into direct contact with large amounts of water, I think it will generally be fine.
This is a story from an irresponsible blog written by someone else.
The best thing to do is to try cleaning a Foam Air Filter Sock that has been applied with filter oil.
You will be able to judge for yourself how much water it is safe to come into contact with.

Is an oil filter necessary?

In the past, there have been times when I was unable to apply filter oil.
I believe that applying filter oil is essential.
1. Fire prevention
2. Improved filter durability
3. Dustproofing
It is essential for the above three reasons. Waterproofing in the rain is not included in the reasons, as the bike is not designed to be ridden in the rain.
The disadvantages in terms of performance will be described in the next section.

Disadvantages of installing an air filter

To be honest, it's hard to tell from the numbers whether installing an air filter changes the air-fuel ratio or reduces performance. It's hard to tell clearly.
There was a clear increase in power when changing from an air cleaner to a power filter.

This is when a Foam Air Filter Sock is used.
It may not show up prominently in the air-fuel ratio figures, but it may have an effect on the Velocity Stack flow speed and the efficiency of air intake.
Commonly speaking, it's definitely better to have no obstructions.
If installing an air filter doesn't reduce performance, then most racing motorcycles would also be running with air filters installed.

Disadvantages of durability without an air filter

I haven't proven it, but I can't say that it's healthy for the engine.
If the idea that it's fine as long as only large debris doesn't get into the engine was correct, then the manufacturer wouldn't have fitted an air cleaner box but a simpler filter when shipping the bike.
At least if you have a mechanic who can disassemble an engine with ease, there's no problem with driving it at full speed without an air filter.
If you're mainly using it on the street, with the occasional want to go full speed, it's a good idea to at least have some kind of filter fitted.
Wire mesh filters apparently allow sand and other particles to get through the mesh.
They're not recommended for use on the street.

The fatal weakness of the Foam Air Filter Sock

There is a slight risk of fire.
Fires are caused by gasoline blowing back from the carburetor.
It can be dangerous if the filter oil has dried and the sponge is saturated with a lot of gasoline.
Backfiring can be disastrous.
Filter oil does not burn, but gasoline is very flammable.
Regular maintenance of the filter is essential.
In particular, be sure to reapply filter oil frequently.

A few points to note about filter oil

The problem is that filter oil gets on the sponge when you touch it.
Some people dislike it because it's sticky.
I don't mind it that much, but I don't like touching other things with filter oil on my hands. You should use gloves when doing maintenance.
Also, oil may get on your trousers or other items while driving.
You may need to accept that it's just the way it is, or take some kind of individual measure, such as installing a guard to prevent oil from getting on them. If you don't mind it, then don't worry about it, it's not a problem.

FCR beginners – put on a filter if possible.

When going air filterless, you need to operate it with firm conviction.
If you cannot judge the safety of the engine, install a filter.
Some people say that it is okay because there have been no problems with air filterless so far.
Some people say that Foam Air Filter Sock is likely to cause fires.
If you only think about the factors of uncertainty, you will not be able to do anything.
However, please make a choice that is kind to your motorcycle.
If you are worried about fire after installing Foam Air Filter Sock, install an air cleaner box and use a standard carburetor. While installing racing parts has the advantage of improving performance, it also has some disadvantages. I apply filter oil and use a Foam Air Filter Sock. Fires can occur even without a filter.
I have not verified which specifications are more likely to cause fires,
but at least if the tuning is properly decided, the risk of fires such as backfires will be reduced.
If there is a burning smell around the carburetor or if you hear even a slight explosion while driving, stop the motorcycle immediately. In some cases, you may be able to do something before the fire spreads.

If I use an FCR – Foam Air Filter Sock, will it be okay to use it in the rain?【summary】

Since this is a summary, I will state the conclusion again.
- As long as you apply filter oil, it will generally be fine.
- You should feel for yourself how safe it is when you clean the air filter.

That was the column.
I occasionally see riders who use sponge-type filters such as Foam Air Filter Sock
who choose not to apply filter oil.
It is generally better to apply filter oil.
What surprised me the most was that the durability of the filters varies greatly.
With motorcycles, there are areas where each person's preferences and ways of thinking can differ.
So I have written about a variety of things, including Foam Air Filter Sock.
Now, I hope you all enjoy maintaining your motorcycle in the winter.
See you again!

CBX1000 Photo Gallery

Here are some photos from previous posts, including the Foam Air Filter Sock.