Join Date: Jun 2016
Location: Jacksboro, Texas
Question about K&N air filter on KLR 650
Skip to last paragraph for pertinent question if you don't want to read the details.
I have a 2011 KLR 650 that I have been chasing a run problem for a couple of months. I have had the carb off and went thru it. I even replaced the slide-diaphragm assembly recently.
The bike has a DG muffler. The carb has a 150 DJ jet and adjustable slide. The snorkel is removed from the air box and no extra holes are drilled. Note: I had a thousand miles with that setup with no run problems. When it runs, it is great.
It doesn't have bad gas. I have drained the tank. Petcock is working (note: this is an over fuel condition). All the obvious has been checked - I think.
The bike has less than 20k on the clock. The carb looks good inside and out.
It also has a K&N air filter that you are supposed to use with the stage 3 carb mod (I am currently closer to stage 2 because I have moved the slide down and am not running the 155 jet as they recommend). I am trying to lean things down some.
Recently, I can run about 60 miles and the bike will start spitting and running extremely rich. The first time it happened, I pulled the carb, and a couple of washers on top of the slide needle had slipped to the side and the diaphragm spring assembly didn't set properly. Problem solved! I thought. I cleaned the K&N air filter, but I didn't really think much of it, it was dirty though.
Ran an Adventure bike toy run in Dec. It was extremely wet, no dust. The bike ran pretty good.
I get out for a ride in late January. The bike starts missing and sputtering again a few miles into the ride. I head back, pull the carb and find nothing, but I put a new slide in it (thinking there might be a diaphragm problem), check everything. I find nothing out of the ordinary. I also installed one of the mixture screws that extends below the carb, just because.
I head out for a ride, no change, the bike runs like crap. Head back, pull the plastic again (thinking about changing to wing nuts lol). Pull the plug, it is gas fouled, not oil fouled. Change plug, check air filter, clean K&N air filter and put it back (note: very few miles since last clean). Bike runs pretty good again.
Today, I finally head out for a lengthy ride with a bud, bike was running great. There are lots of lime gravel roads in the area I live in. We were about 50 miles into the ride, and guess, what?
My bike starts stuttering again. You can see the black smoke from it flooding. I run it back to town at about 20-30 mph with no power.
I get to my shop, begin removing the plastic to install another carburetor I bought to see if it will cure the problem. I also decide to remove the air filter because my brain connects the last few experiences. It is coated with flour like dust. You can't see thru it.
I never have been a big fan of K&N, but this is odd to me. I can't believe I am the only one that rides dusty roads with a K&N filter. When I say dusty, my bike was clean before starting the ride, the rear wheel is coated in powder and the inside of the air box had significant accumulation. And, I might add, that I am not sure the foam filter will offer any different performance, but it does seem to have more surface area.
I should mention that the 1000 miles I put on with the bike after re-jet, muffler change and addition of K&N filter was last year. We had lots of rain that spring, the roads were not kicking up the dust like they are now.
I am switching back to the oem foam filter and going to test it this week.
All this to say, or ask, has anyone else had problems with K&N air filter clogging quickly? **** Here is my question****
Sorry for the book. But, I wanted all the details posted up front.
BTW, my wire harness looks good. Just in case someone asks.