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Beta Evo/rev 3 Air Box Mod

Featured Replies

Hi There

I am having trouble with water getting in my Evo airbox are not able to drian or get it out properly.

I read in another post on TC there is a mod which involves insalling a valve on the botton that will allow the water to drain out.

It does briefly dercribe the mod on page 4 here http://www.trialscentral.com/forums/index....mp;id=6943...it

Can anyone shed anymore detail on this altertation as I dont want to butcher the airbox? eg type of valve to use, size of hole to drill etc etc

Again your help as always is apprecited.

have a look at beta preparation list for ssdt I think it's still on main page

I had a rev 3 with a valve fitted in the air box. In 2 years I used it once and virtually nothing came out.

When do you get the water in? Is it after washing or riding?

I have always found the airbox on the beta to be one of the best for not getting water in. And I have ridden in some pretty deep water!!

Easiest method for getting water out of airboxes is a bit of sponge on a stick! Forget the valve.

  • Author

Chewy:- I linked the same guide in my post. I was hopefully looking for a little bit more detail.

Timp:- Think its when im washing it. I have covered to vents to the rear of the rear mudguard but it still gets in somehow?

Think I may still have to cosider the valve mod but need to know a bit more detail prior to attempting it. As to take mudguard off and do the stick/sponge thing all the time would work but be a bit of a pain.

Cheers

Hi mate im on my second evo and after every wash water gets in, its just something ive learned to live with, its only once week and i clean filter at the same time. do seal airbox as it says to do for scottish though and then nowt gets in while riding.

hi, i have an evo 2010. i have just done the mod myself and find that it helps alot. you can buy the rubber valve diret from beta( john lampkins shop at silsden). it is easy to do. simply drill hole a tiny bit smaller than valve and push it in. easy as that. also try the blue spongey stuff they sell that goes over airbox, described on ssdt prep guide. for both(valve and blue stuff) its about a tenner, cheap as chips for a mod that works.

Edited by jcam

great benifit if you ever drop the thing in water.. i saw one drop into 6 foot of water last year and it was running again in 10 minutes. without the valve it would have meant turning it upside down etc etc..

the mods as easy as jcam says, whats the blue spongy stuff??? have read sssd prep cant see any thing about it ,whats it for.

did mod on rev 3 only used it once, but must say the air box on evo , is a lot more vunerable than rev 3, am going to do it to evo.

i used a tubeless tyre valve , removed centre , with rubber washer each side ,

just found this oldpost from tc, for rev3 but same thing

If you ride a lot of deep water I would recommend fitting a drain pipe to the air box (just in case!)

Buy a valve stem (rear wheel).

Drill a hole at the front and bottom of the airbox (same diameter as the threaded stem).

Poke a straightened out wire coat hanger down into the airbox and out through the drilled hole.

Thread the valve stem over the wire and wiggle it down until it pops out of the hole you just drilled.

Fit the nut and then cut the threaded stem down to about half the original size (don't throw the offcut away).

Unthread the nut to clear off any sharp burrs.

Refit the nut and tighten it all up (no need to seal it but I suppose it wouldn't hurt to use some silicone)

Fit a length of clear piping to the threaded stem.

Thread it towards the front of the bike and down towards the back of the gear lever and let it hang in the sump guard area.

Fit the threaded offcut into the end of the pipe and replace the dust cap.

After each submarine expedition, simply glance at the clear pipe to see if an water has been collected. Remove the dust cap to drain and then refit

Edited by tilertrialler

i had an 09 evo and i bought the stickers from saunders which were a good job on my 10 evo there isnt the prob with the vents in the rear guard

I pressure wash my bike every week and i just clean the filter afterward but there is never any water in the airbox, i dont recommend doing the airbox mod if you're just doing normal trials, if your doing the ssdt then yes I would

  • Author

Thats great peops, just the detail I was looking for!!

Surley its not going to hurt to undertake this mod, just to be sure?

Many Thanks

Be aware that the shape of a tubeless valve on its underside will not allow all the water out of your airbox. A small amount will stay in. The mod is really only for draining the air box as a quick fix. For the bike to run well all the time you need ALL the water out. Most riders clean or at least check their filter every ride and then check the airbox for water. Easy!!

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