Bike won't idle at needed position.

[ChazAWillis]

In May I got my first bike (83' xs400 Maxim). I have just started trying to fix the bike up a little bit and I have little knowledge of what to do. I have taken the carbs apart and cleaned them. I know that the jets need changed but I am not sure what size to get as I do not know the size of the ones in it.

The PO put different exhaust on it and had air box changed to pods. Would the jets make it die out quick since they are not the right size? I done a bench sync on the carbs and the bike runs fine while riding around. I have turned the idle-mix screw out between 5-6 turns (I know it shouldn't be over 3). If I turn it any higher, it will idle but the bike will get lean and the rpm will hang.

I added a couple pictures of my exhaust and some type of filter? Not sure what it is as I am a noob. I noticed the tube looks cut up and don't know if this has anything to do with it.

I am also wondering if i should cover up the holes in the exhaust as they are suppose to be connected but they are just open.

 

[Lou Ranger]

Hi and welcome. I wish I could be more help regarding some of your issues, however, my Maxim came with all stock jets, air box, and exhausts and I never touched anything.

On another thread, though, I read some recent advice to someone to start with what you've got and after you have taken care of all the stuff that doesn't involve buying new parts on spec, you can then try and zero in on an area which might need a replacement.

To start off, I am almost positive you will want to reestablish the cross-over connection between the two pipes underneath the bike (where you show an open hole) assuming there is a corresponding open hole on the other pipe opposite. Apparently, eliminating this design feature can mess with the correct amount of back pressure etc., and from what I've read, these bikes generally run much better with the correct pressure balance restored

The pic below is what I think the original equipment crossover looked like, however, if your P.O. left you with stubs on both pipes, you should be able to rig up some sort of inexpensive cross-over to at least test to see what difference it makes, then decide if it merits a permanent welded repair.