I have connected my existing tachometer "SIG" terminal on the command bridge using 16AWG to the "W" terminal were the black & blue Beta Tachometer is also connected on my 65 amp Alternator. Would like to know if this is the correct way to connect my 2nd Tachometer and should this wire have a fuse? Also will I have trouble calibrating this tachometer as it was originally connected to the alternator on a 302 Ford gas engine.
Zoe
-- Edited by Zoe on Tuesday 7th of May 2013 01:48:01 AM
The Tachometer has 4 switch settings, tried all four today and they all gave me higher RPM readings than the Beta Tachometer, I guess this means I need to change the Tachometer for one with lower settings?
Zoe
-- Edited by Zoe on Tuesday 7th of May 2013 04:06:09 PM
The W terminal will run 2 tachometers. Normally one would use 2 tachs that are the same. I dont know what issues (if any) you will encounter with 2 different types on instrument. I am certain that the 2nd unit will need to be calibrated to the engine and I suggest that you use a photo tach to get this calibration as accurate as possible.
Could not calibrate the old tachometer so replaced it with one for diesel showing lower RPM which is now working the same as the Beta tachometer.
Took her out for engine trials yesterday, everything works fine apart from she gets held on the propeller at 2000 RPM.
So this is what Ihave Beta 60 with 1:1 transmission,prop 13x 9 three blade, the boat is similar to a 26 Tolly, Ihad to stay with the excising 13 prop because of clearance .
A couple of years back when I was looking in to all this you did a prop calc for me which came out at 13x 8 three blade. Given the fact that she gets held on the prop at 2000 RPM what pitch would you recommend?
Judging from the information you have supplied above, I would have a prop shop take 2" of pitch out of your propeller to make it 13x7. This should bring you closer to what you want.
Thanks for the input Stanley at 2000 RPM she is doing 9 knots & trying to get up so shes pushing a lot of water, at 1800 RPM she purrs along at about 7 knots, usually cruise between 6-7 knots. Are there any issues with running the Beta for the rest of the season and not going over 1800 RPM, hauling her out and changing the prop pitch later when she is home for the winter.
You really should do something about this especially if you ever push it over 1800. The severe overloading may have a detrimental effect on the engine and it will definetely have an effect on the engine cooling. Remember that the raw water pump is an important part of the engine cooling system and the lower RPM also slows down the raw water flow through the heat exchanger which therefore limits its cooling ability.
A follow up on last season we hauled the boat and had a prop specialist reduce the prop to 12 x 7 this increased the top RPM to 2500 and @ 2100 RPM we cruise at hull speed. Is this now close enough to the engine max RPM output or should I talk to my prop guy and reduce the pitch some more?
