97 GTX Bogging Down

[hoof-arted]

ust purchased a 97 GTX which needed some overdue maintenance. I corrected most of the smaller issues except one. When I take off from a stop it revs up great and gets up to a top speed of ~50 fairly quickly. After about 10 seconds it starts to lose RPM's a drops to about 6k, fluctuating from 5.5k to 6.5k. If I stop or slow down it will rev back up to 7k fairly quickly and then begin to lose RPM's again.

Here is what I have done so far, I installed new rave valves, cleaned the fuel filters, tried switching the fuel selector from on to reserve, changed the plugs, replaced the water regulator, disconnected the red wire from the rectifier and added some seafoam to the fuel tank. I am in the process of changing the grey fuel lines but so far I have not seen any indication of plugging of the lines. Any idea what I can look at next?

 

[wutagoalie]

Being a 97, id change the original fuel lines. most important, clean the carbs, you may find that your low speed or high speed adjustment screws are slightly off or plugged!

 

[midwestgsx]

sounds alot like the problems on mine, from what i've heard its usually either the fuel lines, carbs need to be gone through, or the fuel selector on/off valve is bad