I finally got a Teleflex tach installed in my 16' aluminum starcraft with 40hp 2 stroke Yamaha model 1989 6H4 L 558276 - 40etlf. I found in the Yamaha shop manual where they mention setting the tach to 6 poles for this particular engine. At warm idle I am showing around 600 rpm and at WOT I am going 30 mph at 2600 rpm. This seems way too low given my prop 11.25 x 14. I know I am over propped based on the michigan wheel website, but dropping down to a 11.75 x 12 prop like they suggest will not give me a 2000 rpm increase. I am still haunted my Ray Neudecker comments that I need a converter box for the tach to operate properly. I found no mention of it in the shop manual and have been searching the web for a few weeks. Am I ok with the electronics and should I start switching props, or am I still missing something with the electronics? Does Auto Zone rent tachs that would work with my motor? Would checking the tach at idle be sufficient to calibrate/ verify it?
Thanks in advance!
Chris
Thanks in advance!
Chris