Hi all,
This is probably a very stupid question . I recently bought some Dual density air filter foam from Rick O, but once i seen it I'm a bit unsure how to fit it. Do i replace the old OE filter with the new stuff which i think might be wrong as the new foam would sit directly on top of the carb stacks. Please help. I would contact Rick for help, but i don't want to be a pain in the arse as i know he is a busy guy.


Cheers
Terry.

pics..

I reckon you chop the old paper out of the old filter, stick this new stuff in and then the job is a fish

that would sound right. make sure to keep the metal mesh on though in the airbox, as its a safety feature against a backfire and flames bursting out your airbox, blowing up your tank and your goolies with em.

this is what im thinking about replacing my filter element with, is it any better than standard performance wise, and will it mean the bike needs to be setup on dyno?

On my MX bike I removed the metal screen and it made quite a difference from what I can remember. I think the screen is more there for litigation purposes than anything, after all the HRC open airbox does not use anything to stop backfiring does it.

That said, the filters I use on the MX bike use a flame retardant foam facing the carbs just in case. I may cut one up and try make a foam filter out of that for the race bike.

Bike_Nut wrote: after all the HRC open airbox does not use anything to stop backfiring does it.

lol, true, but as an added safety feature, it makes since.

Lets face it, our bikes are either worked on by ourselves (the home mechanic), or by a dodgy garage mechanic(plenty of them out there), and there are plenty of situations, regarding the motorcycle engine why flames from the cylinder may return through the carbs to the airbox, eg. dropped valve, top end gone, valve clearances out(so inlets not fully closing) and excess fuel, all can lead to it, etc etc.
yes, it may not happen a lot but it does happen.

with these little factors in mind, all the manufacturers agreed to these measures with their road bikes. as for the HRC race bikes, if the wire mesh method is not used as a safety measure nowadays, i am sure they use something else equally affective. remember they were far less safety conscious in racing in years gone past than they are now

yeh but if the HRC carbs backfire it shoots flame at metal...if the standard one bangs it could light the filter (paper originally) and burn the whole bike

Strange thing tho, cars dont seem to have metal gauze, and they never seem to set filters on fire..........
I just thought it was there to stop the paper deforming when air was been drawn through it.
Cheers
Ian

Im guessing that when it comes to cars their intake paths are a little less direct thus avoiding the flame getting anywhere too far. Then again this probably does not apply to all types.

Hi,
There's an article in MCN this week at the Q & A section regarding air filters. Basically they say the mesh is there to prevent carb back fire, Safety reasons.

Terry.