new 750

just bought a 1982 xj 750 seca

the guy who had it before me took out the airbox and put on pod filters
he also rebuilt the carb
completely tuned wrong got rid of airbox and the plates that go over the jets under the diaphram are missing i cleaned it out and set the screws to 3 turns out and now it wont start
dont know if it was rejetted or not but it ran(not well) when i got it
do i need the plates
will the different filters change where the mixture screws are set

 

accidentaly put tank on on instead of pri it runs now but i still wanna know if anybody can tell me what difference the filters and missing plates will make in setting

 

The missing air jet cover is of no consequence. Yamaha stopped installing them in later models because they weren't needed. Mine has never had them and runs fine. What filter change are you talking about? A change in pod filters should make no appreciable difference. The pods will call for larger jets and maybe even a different needle. The mixture screw settings will depend on the pilot jet size and the condition of the bike so there is no setting that is right by stating a number of turns out. Three is a good starting place. Since this doesn't work try 2 turns and then four. Once running a colotune will fine tune them but the bike must be running to use a colortune.

 

It should have run in the "on" position unless it was out of gas and needed to be in the "res" position. The "pri" stands for Prime and is used to flow fuel into the carbs if they are empty. Such as running out of fuel while riding. It should not be used to run the bike regularly.

 

tank is off the bike and the vacum line is plugged i have it ready for tunning

i dont have a colortune plug so i figured i would turn them out till it bogs coming out of idle but im at about 9 turns out and it still doesnt do it

guess its time to buy a colortune

 

also can somebody tell me how long i need to run the bike before i can pull the plug and tell if the bike is rich or lean from the color of the ceramic

 

It may not bog down with pods. If the pilot jets are too small it can burn all the fuel the pilot jet sends it. The stumble most liely will occur with the screw too far in. This is when the larger mass of air that the pods allow will not pull enough fuel into the intake resulting in a lean mix. IF it runs at 3 turns then I would set them there and ride the bike. A lean mix will cause the bike to stumble just as the throttle opens. Close the throttle ever so slightly and it should run better with a lean condition. If it runs better as you open the throttle ever so slightly then it is rich.