Tri Moto 175 Question

[Chuck403]

Recently, I bought a '82 Tri Moto 175. It ran great the first couple of days, but then it started bogging out at high rev's.

It still starts awesome (First pull), idles great, and soesn't miss a beat till the high rev's then it just falls on it's face. IT doesn't do this all the time, but just about all the time.

Looking at diagrams of the bike, I have seen it has a fuel pump with what I am assuming is a vacuum line running from the intake to the pump. Would that line with a small crack in it be giving me my problems? fuel pump dying? or a piece of crud in the carb that is getting sucked up and blocking gas flow off at higher revs?

If any of you have experienced this before, I'd appreciate some advise and hopefully save me from having to tear the carb apart....

Oh, gas is clean and fresh, no water in it.