carb trouble

I need some help here, I had trouble with my 525exc poping under decel, so i got my dealer to adjust the carb, he said that he played with the fuel air mix screw. It stoped alot of the problem but it still pops a bit, BUT it is using alot of fuel i mean on a hole take of fuel i only got just over 80km (around 48mph) My mates have ktms and there getting around 100km (60mph)or more. what is the problem? can u help me please! :)

Have faith, pardner. You are not alone. The KTM 4-strokes are notorious for their jetting maladies. I think if you browse this forum, you'll find more information than you need about jetting the -520s. As far as range goes, I have an '01 400 EXC and I never plan on going further than 50 statute miles between fillups. I've never really tested what sort of mileage it gets, but I figure a minimum of about 20 miles per gallon - perhaps a little more depeding on how aggresive you are with the throttle. I imagine the 520 gets a little less. This is not normally a problem in races but I can understand your concern with a street bike. Browse the jetting forums and perhaps the MXC gas tank will help a bit. Riding in the mountains of Colorado - elevation ranging from 8,500 to 12,500 feet - I got 89 miles out of a full tank before running dry in the middle of a stream. Good luck, mate!

Don't know anything about the new carb on the 525, but I have an '01 520 MXC that I modified the duration and timing of the Acel. Pump (external on the FCR39, but I think internal on the new carb). The stock duration of the squirt was 3.5 seconds and I cut it down to 1.5 seconds by limiting the travel of the plunger rod. I then timed it to start the squirt at about 1/8 throttle which helped low end response alot. I also ride in Colorado at 5000' to 10,000' abvove sea level so everthing comes too rich here. It also improved my gas mileage (about 25-28 MPG)

Also went to Keihens website and contacted them by email. They are a good group and willing to help. They told me they jet the bikes with the A.P.disabled first and then determine how to tune the A.P. with a dyno and oxygen sensors - wished they lived next door to me so I could use their stuff!

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now