YSB8 Oil Pressure Problem.

[jneely]

I have replaced the oil pressure guage on my YSB8 engine, but from time to time I get no oil pressure. The guage works on an oil line from the engine. A mechanic has told me there is probably gunk somewhere in the system. We have ruled out the line to the guage as a culprit. Any suggestions out there as to where things might be clogging up and how to unclog things? Thanks for all replies.