hmm....

I installed an in line fuel filter and I am out riding and it is misfiring some at higher speeds ? And when off the throttle it backfires some ?
Also we came back to camp and i noticed the exhaust has black residue inside of it ?
I was wondering if it is running too rich ?? Thanks...
 
YZ450.
I am thinking of just replacing the fuel line that I installed the filter on with another line and see if it will go back to normal and say screw it to the filter....I just tried to do (what I thought was) the right thing and install the filter...idk
 
The black part indicates anything BUT lean. it is really possible to have a lean condition at one rpm range and or throttle setting and rich on another. The old rule is to go back to your previous "setting". So for a quick check you can put a fuel line back on without the filter in it. If you still have the miss you can then remove the carburetor and see if you have let some little piece get from the filter and line reinstallation which is keeping your float needle from working right. SET THE FLOAT while you are in there. FYI you are probably NEVER going to find a time when your rig runs RICHER than when you back off the throttle, in gear, at speed. Anyone who thinks otherwise hasn't spent anytime with a meter and O2 sensor. We can get to that part later.
 
There may well be more than one issue. What kind of fuel filter did you install? Some of the little sintered metal ones will flow enough except for full throttle when they don't flow enough. If it's a paper of fine screen this is not usually an issue.
 
There may well be more than one issue. What kind of fuel filter did you install? Some of the little sintered metal ones will flow enough except for full throttle when they don't flow enough. If it's a paper of fine screen this is not usually an issue.
Fuel Filters- 14.jpeg
 
Did you face the big end towards the fuel source? (If you did it could be the problem)I use filters on steel tanks and fiber glass. Plastic not so much. The one you are using there I have broken twice and had the hardest time getting enough line to ride home the first time.
 
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