H34 and Fuel return

[splax]

Silly me ! You can put that reflective tape on the drive pulley on the engine. The prop shaft would not give you a true reading because of the transmission. You shine a light and an instrument picks up the reflections from the tape.
There are different ways to do things. Some are better than others, Sometimes the situation or the availability of equipment determines the method.
I have been out of the testing field for a while...

 

[splax]

I hope that you find the mechanics stethoscope useful. Please post how things go.

 

[PGIJon]

Thanks and will do!

 

[Steverhnm]

You can also get an "RPM Stroboscope" app for your phone. use that name for the search. The app has instructions, etc. Not a proffessional instrument, but good enough for setting RPMs on your boat motor. Save you from yelling back and forth - what are the RPMs NOW!!! haha...

 

[PGIJon]

Thanks Stever... Just loaded Strobily Free. I went into advance mode to set it to display RPM's. I'll have to youtube some disco (since Neal Young doesn't work) in order to ensure its accuracy.

 

[Steverhnm]

I got mine from grappetite. Paid the 1.99. What a deal.

 

[PGIJon]

Well... I received the stethoscope and while it worked well, I could here all sort of rockers rocking, fuel and coolant swirling around, I am not sure I am able to pin down the knocking..... I am also hard of hearing... maybe if it gets worse, I won't hear the knocking at all and all will be well.... yeah right!

I'm going to try and use stereo microphones and look at the sound waves recorded and see if I can pin point it that way.