Possible damage


1977 honda xr75, i decided to take the airbox off now that i have a k&n air filter that bolts up to my carb, i looked at my old filter, and it was half gone, dirty, and old, falling apart. what kind of damage has happened here? anything i should worry about? runs mostly fine.


just curious, did you post here a couple of months ago about wanting to have this bike rebuilt?

you’ve probably burned out the rest of the paper from the old filter already. here is a good example of why you need to check filters once a year or so! dont you wish the previous owner did?!


yes i have posted here before. and i did check once a year, this is the first year ive had it running!


ok, but is there any damage?


Likely less that the K&N will cause. I doubt if you are gong to notice any damage either way.

The missing filter means anything in the air stream or anything lubricated by the engine oil could be worn more than it would have otherwise.

The K&N filters have a habit of damaging MAF’s if you have one, unless you are careful and skilled with the oiling of them.

There have been test both good and bad relating to their ability to filter properly.


i think from your original post, you replaced the old air filter with a new K$N correct?

the OLD filter was the one torn up right?

was it a paper frame, with lighter almost see through paper construction?

if it was all paper, you just burnt the old filter up, and spit it out. do some oil changes, and it’ll be good enough.


yes my old filter was tore up, what did this do to my engine?


oh, i see what you guys were saying, no i know none of the filter got in the engine, what happened from all the dirt getting in my engine?


Joseph, this is an old dirt bike with a carb and points ignition. There are no sensors or computer equipment on this thing.

The K&N filter will do no damage. Chances are, if you notice no problems now, the old filter didn’t do anymore when it crumbled.


go look on “can i have a moment of your time” please, it shows you the filter