Tach and prop issues

[hwsiii]

Re: Tach and prop issues

You are very right.


H

 

[further]

Re: Tach and prop issues

would it affect rpm's?

 

[hwsiii]

Re: Tach and prop issues

Yes, but normally not a tremendous amount.


H

 

[sho3boater]

Re: Tach and prop issues

Last weekend with my 16' I ran 5200-5300rpm on the tach with the 19P, I didn't gps it though. But I did look at the motor and it says 4600-5500rpm range, rated 85HP at 5,000rpm. So if my tach is right maybe 5200-5400 is as high as I should run it. I keep forgetting to take the clamp on tach. It will pull about 100rpm more with synthetic lube in the LU but I ran out this year. I don't know what the weight of this 16' is to compare with yours, also if you have weight in the boat or wet foam that will slow it down. I still have some foam to take out/replace.

 

[cribber]

Re: Tach and prop issues

"Weird thing is the stock tach read 4400 rpm at WOT and the tiny tach read close to 7000 rpm at WOT."

I may have missed it but is your tach set for the right number of cylinders? That looks like it's two cylinders off on the tach settings.

 

[sho3boater]

Re: Tach and prop issues

Tiny tach has the be the right one, some ignitions fire the plug at BDC also then you have double the signal (2 per revolution instead of one). Also they can pick up on a wire nearby and read more than one plug wire. Have to get it right then they work nice. I usually figure a motor will stall around 600rpm so I test them there, or a good idle is around 1K.

 

[further]

Re: Tach and prop issues

yes, tiny tach is working now. i had it wound around the center plug wire and it should be the lower wire. works good now.