Air Filter Clamp

Nasher · 24-06-2018, 09:46 PM

I've had my 1997 M900 almost 4yrs now.

One of the mods it's had in it's past was the airbox being removed and replaced with two huge K&N filters, which look cool and make a nice induction noise, but in reality might not be the best set up for carburation.

The bike is fitted with a Dynojet Stage 2 kit, but interestingly Dynojet don't recommend separate filters, just modifying the standard airbox lid.

The bike runs well enough, but can be a little rough at low revs, and can hunt a bit at part throttle.

I've wanted to try a standard airbox and filter for a while, and purchased one of Ebay well over a year ago.
When it arrived and I'd cleaned it up I realised the lid was in great shape, and it seemed a shame to cut it.

So I hatched a plan to make up a fixture from Aluminium that used the standard over centre clamps.

I finally got a couple of hours to myself yesterday afternoon, and decided to leave the 900SS Mongrel build alone and do something for the monster.

I folded a 12x6mm rectangular bar of Aluminium into a rectangle the same size as the K&N filter that came with the airbox, and having lost access to TIG welding gear recently I fastened the ends with a small piece of angle and some pop rivets. As this is only a prototype at this stage I'm happy with that, but will weld a later version, and one for my 900SS Mongrel if it works well.

The slots for the clamps I cut 3mm deep in my Milling machine with a 2.5mm wide end cutter, then I dropped the outside edge 1.5mm and chamfered the edge by hand with a small file.

It appears to clamp the filter really well, all I need to do now is find some time to fit it to the bike and give it a good test ride to see if it runs better than with the Separate filters.

img

Nasher

Nasher · 24-06-2018, 09:53 PM

Should of added that I'll probably add a small sheet of 1.5 or 2mm Aluminium to the front edge to help deflect any rain away from the filter.

Jez900ie · 24-06-2018, 09:53 PM

Looking good!

Flip · 24-06-2018, 10:33 PM

That does look really good Nasher but out of interest where do the carb breather pipes terminate?

I/m talking about the ones that usually go into the little angular 'boxes' normally fitted to the triangle in the front of the frame.

I only ask as you mention the bike hunting a bit at part throttle and if the boxes are removed and the pipes remain in an airflow (which obviously increases at faster part throttle cruising speeds) they can cause the slides to rise and fall on a steady throttle producing a kind of pulsing feeling as you ride.

350TSS · 25-06-2018, 01:07 AM

Lovely looking job

Nasher · 25-06-2018, 06:55 AM

Quote:

Originally Posted by Flip

That does look really good Nasher but out of interest where do the carb breather pipes terminate?

I/m talking about the ones that usually go into the little angular 'boxes' normally fitted to the triangle in the front of the frame.

I only ask as you mention the bike hunting a bit at part throttle and if the boxes are removed and the pipes remain in an airflow (which obviously increases at faster part throttle cruising speeds) they can cause the slides to rise and fall on a steady throttle producing a kind of pulsing feeling as you ride.

Well spotted Flip.

The breather boxes were also removed before I owned it, and the pipes are now cut off short.

Soon after I got the bike I posted a thread on here as I extended them downwards to under the engine, but experienced all sorts of running issues, including the float bowls emptying on the motorway. http://www.ukmonster.co.uk/monster/s...ad.php?t=53566

I've tried several options now, and each one gives causes some sort of issue.

I have actually brought some boxes, but am reluctant to fit them as I don't like the look of them.

Nasher.

Mr Gazza · 25-06-2018, 05:20 PM

I always respect someone who can think a problem through and make something with the resources available.. Smashing job, simple and perfect.

If you want an ultra lightweight version.
Double glazed sealed units use spacer bar which is actually thin walled alloy box section. 12x6 is available and I'm sure a sealed unit maker would give you offcuts of the lengths needed for a clamp like that, A whole length would only be about 50p anyway.
It can be mitred leaving the outer wall intact to form a square, or four lengths joined with the corner connectors for the sealed units.
The top could be gently punched to form the hollows for the clips.

Used to use no end of spacer bar in model aeroplanes.. Strong and light..

Flip · 25-06-2018, 07:44 PM

Quote:

Originally Posted by Nasher

Well spotted Flip.

The breather boxes were also removed before I owned it, and the pipes are now cut off short.

Soon after I got the bike I posted a thread on here as I extended them downwards to under the engine, but experienced all sorts of running issues, including the float bowls emptying on the motorway. http://www.ukmonster.co.uk/monster/s...ad.php?t=53566

I've tried several options now, and each one gives causes some sort of issue.

I have actually brought some boxes, but am reluctant to fit them as I don't like the look of them.

Nasher.

I have removed mine also, in favour of some DP carbon air scoops P&H had laying about a couple of years ago and I offered them £40 for.

I have heard of people using those old 35mm film cases to put the tubes into before tucking them out of sight so they are in undisturbed air.

They seem to suffer the same effect as blowing across the top of a bottle which in turn causes the slide to flutter about so I just got some coarse reticulate foam we had laying around at work and put a little piece in each tube (I also used it for plugging gaps around the engine sump guard on my green laners to stop them getting clogged with mud)- seems to have done the trick on the Monster so far.

25-06-2018, 08:51 PM

Great job that Nasher. Let me know if you go into production with them.
I also need to have a look at what goes into converting the clip-ons at some point.

Nasher · 26-06-2018, 06:39 AM

Flip
Some good info there, thanks, I need to come up with a plan.

Miky
I'll let you know when I've found some more Ali Bar and got some access to a TIG welder again.

The Clip-ons are easy enough, but most will need the coffin type master Cylinders spaced out to clear the clamps. I'll show you what I mean when we meet up again.

Nasher.

Darkness · 26-06-2018, 08:47 AM

Quote:

Originally Posted by Nasher

Should of added that I'll probably add a small sheet of 1.5 or 2mm Aluminium to the front edge to help deflect any rain away from the filter.

Is that a good solution: it could create an air pressure reduction at the air intake?

That’s the opposite of going for a ram-air effect.

Nasher · 26-06-2018, 09:02 AM

It could do, but then so might a cut down lid.

I don't think it gets enough direct airflow to have any real effect, as you'd need a stream of fast flowing air over the lip, where as I think the whole underside of the tank possibly becomes slightly pressurised at speed.

It's another thing for me to play with if required, but I was thinking more about directing rain away from the filter. Although in my experience Oiled filters like K&Ns tend to repel it quite well anyway.

Nasher.

Nasher · 26-06-2018, 09:08 AM

Quote:

Originally Posted by Mr Gazza

If you want an ultra lightweight version.
Double glazed sealed units use spacer bar which is actually thin walled alloy box section. 12x6 is available

Mr G

I'm not sure hollow box would work.
The clips need something to push down on to work, ie 'go over centre', and the slots I've milled have a floor in them.
Or are you suggesting the top is dented to locate the clips?

Mind you, it's a product I've not heard of or used, and it sounds useful for a few other things.
I think I'll need to do a bit of skip diving on an industrial estate one evening.

Nasher

26-06-2018, 08:07 PM

Quote:

Originally Posted by Nasher

Miky
I'll let you know when I've found some more Ali Bar and got some access to a TIG welder again.

The Clip-ons are easy enough, but most will need the coffin type master Cylinders spaced out to clear the clamps. I'll show you what I mean when we meet up again.

Nasher.

An evening next week perhaps?

Mr Gazza · 26-06-2018, 09:50 PM

Quote:

Originally Posted by Nasher

are you suggesting the top is dented to locate the clips?

Yes, punched would be too harsh a description really, just dented would suffice. Maybe using a suitably shaped piece of hardwood as a drift or form.

No need to go bin diving either, the stuff is so cheap it's easy to buy too much.
Just a matter of convincing the glazers that you are not a competing DIY unit maker.
I'd known our unit maker for a long time when it occurred to me that the bar would be ace for strong spars in models, so it was no problem procuring a supply.

It starts at 6x6 and goes up in 2mm increments to (I think) 6x28 and there are other sizes for internal glazing bars...Well worth chatting up your local unit maker to see what they've got.

The perforated edge is what you see inside your sealed units, the quirky edge holds the sealer. The perforated and quirked edge get longer as the sizes go up. (6x6 shown)
The perforations also make for a good bond when gluing to balsawood ect.

24-06-2018, 09:46 PM	#1
Nasher Registered User Join Date: Jul 2014 Location: Portsmouth Bike: M900 Posts: 1,510	Air Filter Clamp I've had my 1997 M900 almost 4yrs now. One of the mods it's had in it's past was the airbox being removed and replaced with two huge K&N filters, which look cool and make a nice induction noise, but in reality might not be the best set up for carburation. The bike is fitted with a Dynojet Stage 2 kit, but interestingly Dynojet don't recommend separate filters, just modifying the standard airbox lid. The bike runs well enough, but can be a little rough at low revs, and can hunt a bit at part throttle. I've wanted to try a standard airbox and filter for a while, and purchased one of Ebay well over a year ago. When it arrived and I'd cleaned it up I realised the lid was in great shape, and it seemed a shame to cut it. So I hatched a plan to make up a fixture from Aluminium that used the standard over centre clamps. I finally got a couple of hours to myself yesterday afternoon, and decided to leave the 900SS Mongrel build alone and do something for the monster. I folded a 12x6mm rectangular bar of Aluminium into a rectangle the same size as the K&N filter that came with the airbox, and having lost access to TIG welding gear recently I fastened the ends with a small piece of angle and some pop rivets. As this is only a prototype at this stage I'm happy with that, but will weld a later version, and one for my 900SS Mongrel if it works well. The slots for the clamps I cut 3mm deep in my Milling machine with a 2.5mm wide end cutter, then I dropped the outside edge 1.5mm and chamfered the edge by hand with a small file. It appears to clamp the filter really well, all I need to do now is find some time to fit it to the bike and give it a good test ride to see if it runs better than with the Separate filters. img Nasher __________________ Heaven doesn't want me, and Hell is afraid I'll take over.

24-06-2018, 09:53 PM	#2
Nasher Registered User Join Date: Jul 2014 Location: Portsmouth Bike: M900 Posts: 1,510	Should of added that I'll probably add a small sheet of 1.5 or 2mm Aluminium to the front edge to help deflect any rain away from the filter. __________________ Heaven doesn't want me, and Hell is afraid I'll take over.

24-06-2018, 09:53 PM	#3
Jez900ie Pleasantly surprised! Join Date: Nov 2016 Location: Stoke on Trent Bike: M900ie Posts: 780	Looking good! __________________ Monsters don't hide under the bed, they sleep inside the shed

24-06-2018, 10:33 PM	#4
Flip Registered User Join Date: Mar 2010 Location: Beachtown Bike: M900 Posts: 2,188	That does look really good Nasher but out of interest where do the carb breather pipes terminate? I/m talking about the ones that usually go into the little angular 'boxes' normally fitted to the triangle in the front of the frame. I only ask as you mention the bike hunting a bit at part throttle and if the boxes are removed and the pipes remain in an airflow (which obviously increases at faster part throttle cruising speeds) they can cause the slides to rise and fall on a steady throttle producing a kind of pulsing feeling as you ride. __________________ You're perfect, yes, it's true- But without me you're only you!

25-06-2018, 05:20 PM	#7
Mr Gazza Lord of the Rings Join Date: May 2013 Location: Norwich Bike: M900sie Posts: 5,835	I always respect someone who can think a problem through and make something with the resources available.. Smashing job, simple and perfect. If you want an ultra lightweight version. Double glazed sealed units use spacer bar which is actually thin walled alloy box section. 12x6 is available and I'm sure a sealed unit maker would give you offcuts of the lengths needed for a clamp like that, A whole length would only be about 50p anyway. It can be mitred leaving the outer wall intact to form a square, or four lengths joined with the corner connectors for the sealed units. The top could be gently punched to form the hollows for the clips. Used to use no end of spacer bar in model aeroplanes.. Strong and light.. __________________

25-06-2018, 01:07 AM	#5
350TSS Too much time on my hands member Join Date: Jan 2013 Location: Shipbourne Bike: M900 Posts: 1,420	Lovely looking job

25-06-2018, 08:51 PM	#9
Miky Guest Posts: n/a	Great job that Nasher. Let me know if you go into production with them. I also need to have a look at what goes into converting the clip-ons at some point.

26-06-2018, 06:39 AM	#10
Nasher Registered User Join Date: Jul 2014 Location: Portsmouth Bike: M900 Posts: 1,510	Flip Some good info there, thanks, I need to come up with a plan. Miky I'll let you know when I've found some more Ali Bar and got some access to a TIG welder again. The Clip-ons are easy enough, but most will need the coffin type master Cylinders spaced out to clear the clamps. I'll show you what I mean when we meet up again. Nasher. __________________ Heaven doesn't want me, and Hell is afraid I'll take over.

26-06-2018, 09:02 AM	#12
Nasher Registered User Join Date: Jul 2014 Location: Portsmouth Bike: M900 Posts: 1,510	It could do, but then so might a cut down lid. I don't think it gets enough direct airflow to have any real effect, as you'd need a stream of fast flowing air over the lip, where as I think the whole underside of the tank possibly becomes slightly pressurised at speed. It's another thing for me to play with if required, but I was thinking more about directing rain away from the filter. Although in my experience Oiled filters like K&Ns tend to repel it quite well anyway. Nasher. __________________ Heaven doesn't want me, and Hell is afraid I'll take over.