I have a 1999 Javelin R 19 w/ a 1999 Johnson 150. It has a 3 blade SS 14 ¼ x 22 prop. It will run 60 mph WOT but the tack only reads 3400 rpm. Doesn’t that seem off? I am thinking the tack is off but I wanted to get an opinion from you guys. Do you think that sounds right with that boat, motor and prop combo?

I am working on putting an external tack on it and see what that shows.

Also what is normal water pressure for that motor at high rpm? My gauge shows 20ish.

Thanks,

Cy