Air Filter Finding,s

[TrailCub]

One thing I'm curious about though, the parts diagrams show that the air intake "snorkels" have some kind of internal screens but I'm pretty sure my bike doesn't have these. What do they do, exactly?

If you are referring to #7 in this drawing: 

http://www.hbhonda.com/fiche_section_detail.asp?section=121807&category=MOTORCYCLES&make=HONDA&year=1989&fveh=2914

They are inside the airbox itself and are only meant to act as induction noise reducers. There is no harm in removing them and there may be some benefit beyond the increase in induction noise.

Thanks clarkdw, yes, those "mufflers" are exactly what I was wondering about.

Glad to know they don't harm performance, but I'm curious - Do they make much of a difference in the sound?

[xstreamcanadian]

i tossed mine as the foam around them fell apart, and when runnig(not often) my bike sounds sick

[clarkdw]

Glad to know they don't harm performance, but I'm curious - Do they make much of a difference in the sound?

Little louder, to me it sounds nicer without them.

[xstreamcanadian]

oh sorry. sick=good. slang

[schedMas]

As you may have known or looked at any  of my post,s I am looking at replacing the whole air filter to a more compact unit feeing up space for when I cut the bottom out repair the,"ding(see end)"and increase the bottom to get more fuel in..

Been messing about with the original filter/plate and my findings are;

1, Cleaned out paper element and thought I,d lightly oil it with a very light oil....result  Bike would not start and smelled like flooding.

2, Removed the element completely,and used a very dense open cell foam, bike started idled well but would not rev above 9,000 Rpm.

3, Used very closed woven cotton 5 ply thick and layered 4 times, bike revs pulls like a loco but running rich.

4, I have got some Japanese matting,which one layer will go underneath the filter between the rubber trumpet,s and the metal mesh guard on the underside of filter plate and used above encased in the close woven stockinette.

To restrictive and bike may not start, slightly restricted and bike may run but lack punch, to free flowing and runs rich-which maybe overcome by dropping the needle a notch or 2.

The NC 32 engine and carb flow seems to like a certain amount of restriction in the air delivery to operate within its parameters, not uncommon with other engines of any type.

So will update findings on matting and see how it goes, but a bit peeved off, as its very windy here I had the tank on a wheelie bin while I was fiddling about,next thing bang crash wallop, the bin overturned and tank was thrown onto some paving slabs and up against metal rear gate, another ding and lots of scrapes, scrapes G3,d out fairly well but ding had broken flakes of paint off so quick cover with ins tape and blue marker pen and it least looks not to bad, but more planish work once bottom is cut out, Thinking, is it" Friday the 13 th, broke a mirror,seen just one magpie, hurt a black cat etc etc"
such fun. :'

I used a fish aquarium filter element on my bike, been riding with it for 7 months now, no prob on the performance, doing 26km per liter, my bike is a workhorse, doing 55kms daily 6 days a week

[rigwit]

My way is going to get 2 original filter cases, remove bottom rubber intake trumpets, 2 and 3 are higher than 1 and 4, so 2 cases will give me 4 low,  then have a aluminium plate drilled to take trumpets sockets as like the original case bottom, have the plate machined up to take an ITG megaflow filter.          Leaving lots of room for expanding the tanks capacity, as this would be  low then no prob with high weight. Also allowing room to get COLD air to the carbs.

[TrailCub]

rigwit - take lots of pictures!  This sounds like a very interesting experiment

[rigwit]

Update.. so got.

2 filter housings,all screws, rubbers, removed.

Got new 5mm +6mm ss Allen head set screws for head and filter mount bands

The JC 30 filter I was hoping to use is to wide at 149mm ITG build filters to customer's spec so sent a e-mail off nothing back as yet will give it till Tuesday if nothing  will ring them, as I cant proceed until I know ITG can deliver.........

All rubbers and bands been ultrasonic cleaned and old traces of Honda''s glue removed..

[rigwit]

OK about due another update.

had 304s 10mm plate cut turned and bored to fit adapter, back at machinist as bit of a clearance prob so shaving off 4mm.

alloy plates are marked up and ready to go to the water-jet cutters next week

ITG filters never got back to me so once alloy base-plate is done sending them off to ram-air for filters to be made having one base-plate with all 50mm holes in for intake trumpets,and having another cut so 2 base-plates each for2 carbs so once back will have to put some pics up.

[rigwit]

OK got base plates back you will see 2 are full for all carbs and  2 are done for 2 carbs each--still to do is offer up to check clearance and you will notice one big intake trumpet these only have the full radi and i need it to get the finished radius then 7mm strip welded to make a skirt for filter then perforated sides and cover for 2 reasons, 1 for obvious blow back protection and 2, so the filter does not implode under vacuum.

Also the exhaust flange and link adapter before polishing to mirror, had the exhaust on before the change of plane in adapter and it sounded sweet..

[guntherrex]

interested to more results on this