inthedirtagain
Petty Officer 1st Class
- Joined
- Aug 10, 2011
- Messages
- 321
Im waiting for my TinyTach to arrive in the mail so that I can confirm my RPMs for this outboard. Under the dash of the 1969 Silverline is a 4-wire tach with 2 of the wires not connected to anything. Any ideas what they are for? I can't see any markings. The original tach does work, but I'm not sure of its accuracy (chasing a pitch problem with new prop). I have read about using a shop tach on the rectifier, but with the Thunderbolt ignition, I don't think my Sears engine analyzer is reading it correctly. I can change between 4/6/8 cylinders, but it still never matches the factory tach. Its reading considerably higher at all settings. Thoughts/advice?
For the record, the tach and outboard are original to the boat. Compression is 130psi x 6, verified throttle advance, but have not verified max timing @ WOT. On this lightweight 16ft deep-V, I was hitting 5200 rpm with a beat up 3-blade 17p prop. I bought a new 16p to try and carry a full load while tubing/skiing with the kids, but its maxing out at about 4400 rpm (speed not checked). Here is a short vid of my boat showing the tach:
https://www.youtube.com/watch?v=iYN7iUsLyqw
For the record, the tach and outboard are original to the boat. Compression is 130psi x 6, verified throttle advance, but have not verified max timing @ WOT. On this lightweight 16ft deep-V, I was hitting 5200 rpm with a beat up 3-blade 17p prop. I bought a new 16p to try and carry a full load while tubing/skiing with the kids, but its maxing out at about 4400 rpm (speed not checked). Here is a short vid of my boat showing the tach:
https://www.youtube.com/watch?v=iYN7iUsLyqw