Okay so this is a first time issue... I recently got into an accident with my MC40, ended up getting everything fixed from the insurance.

I decided well I might as well replace a slew of parts that were going bad, and end up upgrading a couple that needed to be. The list was: Belt tensioner, Timing chain tensioner, Bypass Valve, Supercharger Intake Tube, and then finish it off with a 15% pulley.

I installed piece by piece and everything was running fine up until I installed the 15% reduction pulley. (Mind you, I would replace one part run it for a couple days see how it ran, and then replace another part and repeat). NOW I have this terrible knocking noise coming from the belt tensioner... and I know what this sounds like are you sure its coming from the tensioner. YES I am 100% positive. I have full compression on all of my cylinders, and the entire block was rebuilt less than 2 years ago. It looks as if the idler pulley between the supercharger and the alternator seems to be off on one end.

The pulley install was smooth, it was pushed fully to the rear just as MINIMANIA instructed, everything was tightened down to 5lbs/ft. and quadruple checked for proper torque measurements. I cat figure out why this is happening now. I will include pictures here shortly.

 

Did you install a shorter belt?

 

Yes I installed the belt included with the kit direct from MINIMania.

 

Wow. I'm dumb. After checking the belt I found there was a type of beetle that decided it was going to attach itself to the idler pulley. It smashed and got stuck. Cleaned it now the knocking is gone.