All the WD40 does is make a temperary seal Just like useing soapy water . and yes the rpms should go up if there is a leak. Once The motor is at Oper. Temp. Shut it down let it cool The retighten the whole system (intake & exhaust) And then you should be good to go. Hope this helps. }[oooooo]
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NovaMan/Twisted6/Larry