Warning on std air box and K&N filter
Posted: Thu Jan 17, 2019 11:42 am
Motivated once again I went into the man cave to finally fit the TDMR40’s I have for the white TRX.
Removed the air box and took off the std CV carbies and the first thing that was apparent is the inlet rubbers. Shot to pieces so into the spares and put on a new pair of genuine rubbers.
Looking into the inlets I was amazed at what I found. I knew the inlet valves had been replaced recently but who ever did the service needs a clip over the ears.
Inlet ports had was partially covered with tiny black balls of a gritty feeling material.
Rod to the rescue and informed me from the photo, has the bike had a foam filter fitted. When they degrade and mix with oil /fumes from the breather you get this same outcome.
But it’s the original airbox and K&N Filter fitted.
So I went back to look at the airbox and found the culprit. The foam fitted around the airbox to seal it under the tank was degrading and falling apart especially under the inlet horn.
Opened the airbox to find how this was getting past the K&N filter.
There are 4 tangs that sit against the air filter to hold it hard against the box to help seat it.
Great for the std plastic framed std air filter but with a flexible K&N rubber frame the centre 2 actual sit the other side and allow air to sneak in under the removable air box horn section that allows you to access the air filter.
So if you have a std trx , check the foam surrounding your airbox. If degrading remove it all. If you have a K&N filter fitted find a way ( maybe a drop of sealant to hold the filter hard against the box in the centre before fitting the horn or lid.
Removed the air box and took off the std CV carbies and the first thing that was apparent is the inlet rubbers. Shot to pieces so into the spares and put on a new pair of genuine rubbers.
Looking into the inlets I was amazed at what I found. I knew the inlet valves had been replaced recently but who ever did the service needs a clip over the ears.
Inlet ports had was partially covered with tiny black balls of a gritty feeling material.
Rod to the rescue and informed me from the photo, has the bike had a foam filter fitted. When they degrade and mix with oil /fumes from the breather you get this same outcome.
But it’s the original airbox and K&N Filter fitted.
So I went back to look at the airbox and found the culprit. The foam fitted around the airbox to seal it under the tank was degrading and falling apart especially under the inlet horn.
Opened the airbox to find how this was getting past the K&N filter.
There are 4 tangs that sit against the air filter to hold it hard against the box to help seat it.
Great for the std plastic framed std air filter but with a flexible K&N rubber frame the centre 2 actual sit the other side and allow air to sneak in under the removable air box horn section that allows you to access the air filter.
So if you have a std trx , check the foam surrounding your airbox. If degrading remove it all. If you have a K&N filter fitted find a way ( maybe a drop of sealant to hold the filter hard against the box in the centre before fitting the horn or lid.