VF750F 1983 Sudden Performance drop

Hello everyone,

I am a automotive technician so you could probably imagine the troubles I am having starting to work on bikes lol. I have a 1983 VF750F with the V45 I believe. I had her running and well at that she was as quick as a 1986 VFR750. After a good little run one day I notice a performance drop throughout the mid and high range. No misfire but while the RPM lower sometimes a pop but still runs fairly quick just not as spectacular. I have replaced plugs and wires as a preemptive strike against the problem as well as removed the fuel pump and gravity fed the carbs and ran sea- foam through the carbs.... Sounds to m like a fuel filter (EXCEPT it doesn't have one besides the petcock and the seat screens. So as far as I know the fuel is good. Not sure about spark it is blue-and a little orange. Does not smoke and smells rich. Idles good as well and choke works on all four cylinders, diaphragms seem to move well as well. I am at a total loss.... I'd really appreciate some experienced insight on one of these bikes. I dont get the same performance as I originally had it just dissapeared like a magic trick.

Thanks
-Steve

 

Sorry one more thing to add. Runs well not under load.....