General maintenance for a '02 Silverwing 400

Hey everyone,

Recently, my Silverwing's starter motor failed. Had a workshop mechanic opened it up and replaced the carbon brush holder that was long gone. The o-rings crumbled so I had that changed too. The past 7 owners probably never replaced any parts in the past 18 years because it was COVERED in black gunk.


The old starter motor brush that came out of my Silverwing.


What a new starter motor brush looks like


Anyway, I checked the air cleaner that's located on the right side and noticed it's covered in a layer of... black gunk as well? I'm currently doing 5.94L/100km (that's 39.6mpg) after dumping a full bottle of STP Complete Fuel System Cleaner into the tank.

Should I see any improve to fuel consumption if I changed to a new air cleaner? 39.6mpg is ridiculously low given the quotes I'm seeing on the forum. Appreciate any inputs, thanks!

Yes, you will see an improvement in fuel economy.

The best fuel economy is between 60-80kph (at least for 600 Silverwings) and a steady hand on the throttle. But, as I understand it, Singapore is a densely crowded city so there’d be little chance of cruising at ~65 kph for very long. Stop & Go traffic will not improve fuel economy.

Please let us know how you get on with this.

Cosmic_Jumper wrote:

Yes, you will see an improvement in fuel economy.

The best fuel economy is between 60-80kph (at least for 600 Silverwings) and a steady hand on the throttle. But, as I understand it, Singapore is a  densely crowded city so there’d be little chance of cruising at ~65 kph for very long. Stop & Go traffic will not improve fuel economy.

Please let us know how you get on with this.

Yeah there's not much chance to cruise for long periods of time in Singapore. Maximum of 15-20 minutes on the highway and it's back to idling at the traffic lights.

Am considering to get a cheap aftermarket one for about $20 to save on cost. Will update when I get around to replacing (hopefully with photos!)

Okay so I managed to find a guy who was selling a lightly used air cleaner (genuine Honda part), presumably with about 70-100km on it for about $30 (USD$22). Not a bad deal considering that I would had paid 3-4x the price if I bought off the Honda parts site.

Immediately set off dismantling my Swing to replace the air cleaner and lo and behold..


The old air cleaner choked up with a bunch of black gunk.

I knew the air cleaner on my Swing was covered in black gunk when I peeped it through the cover, but I wasn't expecting it to be this bad. LOL.

Anyway, here's a comparison shot of the lightly used air cleaner that I bought with the old one.


The difference is immense.


Air cleaner change took me slightly over an hour to get it done. Overall, I learnt a great deal replacing my own air cleaner; am definitely a step closer to fully understanding my Swing.

Given that spares are so expensive for your location you might want to attempt to thoroughly clean that old air filter. And once adequately dry spritz it with a mist of light oil.

Or remove the old paper element, saving the frame and metal mesh and replace the paper element with foam filter material. I recall seeing posts here about doing that but I’m unable to find them. So do check YouTube for that.

Cosmic_Jumper wrote:

Given that spares are so expensive for your location you might want to attempt to thoroughly clean that old air filter. And once adequately dry spritz it with a mist of light oil.

Or remove the old paper element, saving the frame and metal mesh and replace the paper element with foam filter material. I recall seeing posts here about doing that but I’m unable to find them. So do check YouTube for that.

Sorry if I sound stupid, but may I know what sort of light oil is suitable for application after deep cleaning the old air filter?

dovahkiin wrote:

Sorry if I sound stupid, but may I know what sort of light oil is suitable for application after deep cleaning the old air filter?

At the moment that “light oil” escapes me. However K&N aftermarket filter kits do come with a light oil which is spritzed on their paper filter elements after cleaning and drying. So maybe just mist on WD-40 —some kind of light oil which will attract and trap dust and dirt yet still allow air to pass.

Lots of good info on YouTube.

Even though in not a fan of washing paper air filters, a lot of people do, warm water and generous amount regular dish soap or plastic safe degreaser, allow to fully dry out in the sun, overnight ?? like CJ mentioned a coat of wd40 will work fine, again let it air out for 1/2 hour or so to evaporate the volatile chemicals. The oil will help repell moisture and trap dust.

I did do a foam filter mod on my original filter and used for a month, while I sourced new oem style, no problems, cut out old paper and used 2 layers Uni-filter foam sheets fine 60ppi and coarse 30ppi on outside layer, I used their propietary/specific oil, etc. The thing is I had all materials on hand for use in my smaller scooters, is probably cheaper/easier to source a replacement aftermarket oem type like Hiflo filter, etc.

zrx212 wrote:

Even though in not a fan of washing paper air filters, a lot of people do, warm water and generous amount regular dish soap or plastic safe degreaser, allow to fully dry out in the sun, overnight ?? like CJ mentioned a coat of wd40 will work fine, again let it air out for 1/2 hour or so to evaporate the volatile chemicals. The oil will help repell moisture and trap dust.

I did do a foam filter mod on my original filter and used for a month, while I sourced new oem style, no problems, cut out old paper and used 2 layers Uni-filter foam sheets fine 60ppi and coarse 30ppi on outside layer, I used their propietary/specific oil, etc. The thing is I had all materials on hand for use in my smaller scooters, is probably cheaper/easier to source a replacement aftermarket oem type like Hiflo filter, etc.

Thanks for the reference picture and advice. This will come in handy when I want to save cost in the near future


Also, I've figured the problem with my poor fuel consumption.

My Swing 400 has a T-Mode button and I've been turning it on every time I go out for a ride. Did it because there was a substantial increase in performance (and I was loving every bit of it).

What I did not realize, was that with added performance comes increased fuel consumption.



These were my mileage and price paid for petrol (in Singapore dollars) as well as my calculated fuel consumption. 29th May is the latest one where I did not turn on T-Mode.

Comparing fuel consumption of 25th May's to 29th May's:

25th May - 33.67mpg (6.99L/100km)
29th May - 50.91mpg (4.61L/100km)

Shall be using my Swing's T-Mode button sparingly now!

I wish I knew how that T-Mode switch worked. Even though I recall seeing a pin-out diagram for the JDM 400 T-Mode ECM many years ago nothing there suggested a “how to”.

The K&N air filters are a cotton element (not paper) that use a special oil. The cleaning kit (sold separately) will clean and re-oil the filter for many years. It takes me 45 min to an hour to remove the filter on the Silver Wing so at replacement time it got a K&N that doesn't need service for 30K miles or longer. I have used them for YEARS in motorcycles/ cars or trucks. The drawback is of course price... But if you plan to keep the scoot for a long time it will save $$$. Sometimes you can find them on eBay used and clean it and it is like new.

Honda is notorious for HIDING the air filter LOL. My Goldwing 1800 filter was buried and took 2-3 hours to change IF you knew what you were doing. It also got a K&N. Now the Forza is a breath of fresh air as it is very easy to remove and clean or replace...the engineers must have screwed up on it!!!

The advantages or disadvantages, of using K&N filters, have been well documented over the years, the thing is, scooters air filters get very dirty, both my scooters air filters were virtually clogged at relatively low mileages 5-10k miles, possibly due to where they draw air from, area in top of rear wheel. IMO extended change intervals are not a good idea, because no matter type of filter, it would get just as dirty !!, your engine won't breathe right and really impacts fuel economy. FIY, no, I don't drive any dirt roads, etc.

Wich brings me to my personal drawback on K&N air filters, on top of the 30-45min. replacement time, you have to wash/dry/oil filter, maybe an overnight process? Not to say the Hazmat dangers nowdays and/or gear you should wear when doing so, waste of water, etc. !!. Or you can just install a new paper filter, ride scooter immediately and/or go on with life. I can almost buy 3 Hiflo air filters for similar price of one K&N. Not worth the hassle IMO.

Cosmic_Jumper wrote:

I wish I knew how that T-Mode switch worked. Even though I recall seeing a pin-out diagram for the JDM 400 T-Mode ECM many years ago nothing there suggested a “how to”.

Hello Cosmic Jumper,

Maybe I sound stupid now, but what is a T-mode switch? 
Where would that switch be in the SW?
And what does the switch do for the SW?
How does the switch work?

Keep in mind that I'm living in Europe and maybe that the T-mode switch is not available for European SW's.

Thank you in advance for your effort

" Maybe I sound stupid now, but what is a T-mode switch? "

The only stup** question, is the one that's never asked!!

In any case the T-mode switch, it basically changes the mode of the ECM/ECU/PGM-FI box for more power/acceleration, it was a feature available on some other market models besides the US, some old discussions can be found here on a search, very little found on a general google search. Supposedly on the SW-T400/600 GT circa 2010 ??

Aahhhh that might be why I've never seen the switch
My SW is a FJS400D from 2008

Thnx for your answer

Have a great evening

Ok, after seeing those pictures I really fee the need to check my air filter… how do I get at it?

If you do a search you'll find 'Air Filter Pictorial'. It's all there