Drak
New Member
This is what i took out of my Rc390 One stock KTM air intake. Witch i will note is one of the worst air intake systems i have ever seen. Pulling air from the back of the bike all the way to the front. And replaced it with a K&N Rc 9630. I used a 2.25 to 2.5 reducer to go from the intake to the pipe. The pipe has a 45 degree bend to go over the rear shock and connects directly to the filter. then i had to get some 7/16 rubber hose to connect the old hoses to my new intake. after all this i took it out for a test run. It was amazing. i could drive in 6th gear at 3k RPM with no problem. it would fly through all the gears with ease. then i found a problem. driving up the side of a mountain instead of sifting down i decided to open it up full throttle just to find half way up the bike runs out of steam. so i shift down to find that that gear also dos'nt want to pull it. so i go down another and another. so i stop on the side of the hill to find nothing wrong with the bike. so i take off again and make 6th before i reach the top with no problem. so i did some test and every time i reach full throttle after a few seconds the bike would shut down. Not die but lose a lot of power. so i fount out the problem. my stock exhaust wasn't letting out enough air and it was killing my ponies. it was an interesting problem never had it before. Question though. Am i the only person to take out the stock system, and why wound someone want to pay 50 dollars to put in that little chocked air filter when 70 dollars will replace the whole thing?