Yamaha TRX850 Enthusiasts Forum

Well, you're all about to find out how cheap I am!

I have ordered some parts for the TRX, including a new airfilter, & I plan to gut the old one, remove the paper filter & put some filter foam in there. I'll put the frame back together with bolts.

I reckon it should free up a bit of airflow, which shouldn't be a problem, & will become washable, rather than throw away.

Can anyone foresee any problems with this?

prob by the time you purchase the other filter and then the filter foam to mod the old one you could just go out and buy a K & N filter and have a washable filter for the same price anyways.. I made my own filter too modelled on the RAMAIR twinsock filter to fit over the stacks on my FCR's and it's working fine after bout 5,000km's and 6mths so far ( 20mm thick filter foam)

I might add you will also notice a difference with the K & N filter down low they breathe a lot better.. First mod I made when I first purchased my TRX all them yrs ago.. good investment...

Fair enough, I thought it might be worth a try if the foam was cheap enough, better than throwing the old filter out!

Ok, so I did this, I have been running it for a month or so, in the next few day, I will swap over to the original & see what the differences are, stay tuned!

If you search the threads MV you`ll find members who`ve gone to great trouble modifying standard airbox`s I believe Phuk was one such.
Kedo even market round push in`extra` filter elements for folk who go down this route,cutting holes in the front of the airbox housing.
Gains CAN be found but the better/less time consuming option is to junk the airbox altogether using K&N or Ramair filters. Best of all though get some big ole squirters for her(Keihin FCR41`s),you`ll be amazed at the extra ponies you`ll find you`re riding.

Mincehead wrote:Best of all though get some big ole squirters for her(Keihin FCR41`s),you`ll be amazed at the extra ponies you`ll find you`re riding.

This is v. true, even with a standard-ish airbox still fitted and if you do the TPS mod you'll find one or two more, allegedly.

Mincehead wrote:If you search the threads MV you`ll find members who`ve gone to great trouble modifying standard airbox`s I believe Phuk was one such.
Kedo even market round push in`extra` filter elements for folk who go down this route,cutting holes in the front of the airbox housing.
Gains CAN be found but the better/less time consuming option is to junk the airbox altogether using K&N or Ramair filters. Best of all though get some big ole squirters for her(Keihin FCR41`s),you`ll be amazed at the extra ponies you`ll find you`re riding.

Yep - I spent time and money trying to sort out the standard airbox / carbs. Gains are negligable.

Because Yamaha (and the other major players) spend millions of yen/euro/dollars to get a reasonable compromise between airflow and passing noise tests - then Joe Amateur comes along with a piece of memory foam and thinks they can do better - very, very occasionally Joe Amateur gets it right but more ofter gets it wrong......................do you really want to feck your cylinder bores/pistons and have even more oil burning issues?

It was more a cost thing, rather than performance per se, $25 for enough air filter foam to make 4 x reusuable filters, vs $50 each for disposable Yamaha filters. Performance wise, as long as they weren't any worse, I would be happy.

dandywarhol wrote:do you really want to feck your cylinder bores/pistons and have even more oil burning issues?

You're meaning more air = less filtering, more crap in the engine, or is there more to it?

Thats what I mean MV - when you consider the engine is gulping in roughly 30,000 litres of air for every litre of fuel - that's a helluva lot of crap to potentially suck in.........

I thought it would be more along the lines of 14.7 litres air/per litre of fuel...

Anyway, I'll take out the filter this weekend & see how dirty is is, then swap the original in & see what the differences are.

14.7 to 1 by MASS, 30,000 :1 by volume...............next time you hear the induction roar on full throttle do you think you're putting in fuel at 14.7 times ratio?

Ah, I see! The induction roar is very hard to hear over my Leo Vince slip ons