I put backing on my BC reel but why does my main line go on uneven? I never had a problem before?

Is the worm gear functioning properly? 

If the backing went on level, something must have changed when you spooled the main line. What type knot did you use to attach the main line? See if the knot dug in or created a lump on the spool. Did you run the line through your fingers putting tension on the line? If so, you may have been unknowingly pulling against the level wind. If the level wind is suspect, apply light finger pressure against the line guide in the opposite direction it is moving as you reel. Feel for rough spots or hesitation, especially at the ends when the guide changes directions.

If the backing went on level, something must have changed when you spooled the main line. What type knot did you use to attach the main line? See if the knot dug in or created a lump on the spool. Did you run the line through your fingers putting tension on the line? If so, you may have been unknowingly pulling against the level wind. If the level wind is suspect, apply light finger pressure against the line guide in the opposite direction it is moving as you reel. Feel for rough spots or hesitation, especially at the ends when the guide changes directions.

I did the UnI to Uni knot. I was putting pretty much tension on the main line to get it to lay tight in the spool! I will try to take it off onto another BC and start over! Would it cast ok like it is?

I agree with Delaware Valley Tackle, check the worm gear, especially at both ends.  I've had some cheaper bc's in the past that would basically hiccup when the level wind would hit the end of the worm gear and start back the other direction.  If I had tension on the line that wasn't directed at the center of the spool, then it would pull back on the level wind and make it stick for a few handle turns causing uneven line lay like you mention.

If it is the worm gear not working properly, check to see if all the screws holding the sideplates to the frame are tight.  Occasionally that would happen if I had just serviced a reel and not tightened everything up or they just worked loose allowing more play for the worm gear which would bind the level wind up.  Again this was on cheap (<$60) bc's, so I don't know how common that might be in higher quality reels because of better construction. 

Good luck finding the cause and getting back on the water quickly.

I have had this happen several times using my Berkley spooning station. When I take the rig fishing the line evens out. Blows my mind as to why and how.

I put backing on my BC reel but why does my main line go on uneven? I never had a problem before?

How are you spooling the line onto the reel? If your holding your rod while spooling, it must be held straight. Holding the rod too the left or the right will cause the line to favor the left or the right.

If your using a spooling station, the spool must be attached to the spooling station exactly in the middle so when you attach your reel to the station the line goes on straight on and not to the left or right which will cause the problem your having. Check it out. Hopefully that is the problem and something mechanical. Good luck.

I put backing on my BC reel but why does my main line go on uneven? I never had a problem before?

How are you spooling the line onto the reel? If your holding your rod while spooling, it must be held straight. Holding the rod too the left or the right will cause the line to favor the left or the right.

If your using a spooling station, the spool must be attached to the spooling station exactly in the middle so when you attach your reel to the station the line goes on straight on and not to the left or right which will cause the problem your having. Check it out. Hopefully that is the problem and something mechanical. Good luck.

Yes I was using the spooling station and I thought I had the reel and line lined up wright! It is not real bad just alittle more on one side than the other!  :-/

Thanks for the info guys I have learned something from this post! So it was the knot or too much tension on  the main line! Thanks Again