That was likely your issue, if your meaning the HSN housing that holds/pinches down on the banjo fitting where the fuel line connects. If that's not tight, it sucks air, a lot.
Yeah, it's worse on some than others. The savage is pretty bad for it since the pipe is fully suspended in air and flops around when jumping. Usually not so bad on buggies/truggies as the pipe usually rests on the chassis. I got tired of the coupler/gaskets going bad quickly on my savage and...
Also check the gasket for the header. THat gets beat up pretty good over time and a lot of pipe pressure can be lost right as it exits the engine which can cause poor tuning.
Whenever I need a refresher, I go over these:
Paris Tuning PDF - my site
Which is about once a year as I don't drive...
I think the SH28 uses an internal OWB. So it's always saturated with fuel. However, if you put a truck away without running the engine until it's dry, the fuel that sits in the crank case evaporates and leaves a heavy oil on the OWB needle bearings, then they don't move freely and grab/release...