Power Issue?

[EazzeO]

Hi all,
I bought a new to me boat last year. Its a 14 foot bowrider that came with a johnson 70 hp vro. Well the motor was shot so i sold it for parts and bought an 80 hp merc. It was close to the end of the season by the time i got the motor on it and was only able to take it out once.

Durring my outing I had a buddy with me (big boy) and the boat would not plane out. As soon as he went to the bow it planed out but still not right away. I was wondering if there could be a problem with the motor or is it just because the bow is so light. Also could it still be under powered? When i bought it the cap plate was missing and i figured that 10 more horses wouldnt make much of a difference. My first boat was a 14 foot with a 50 merc and it took right off.

Where should i start?
Thanks to everyone.
Cheers

 

[milehighboater]

Re: Power Issue?

I have a 17.5 foot with a 75 merc and I have no problem getting on plane. I am normally running at 6000+ ft above sea level too. I think my hull weight is around 1000 lbs and the boat does around 35 mph at 5100 RPM. Back in Missouri I was getting just above 40 mph. I don't know where to start but I think there may be a few kinks that need to be worked out.

 

[turbinedoctor]

Re: Power Issue?

What is the weight of your boat? What prop are you using? What rpm's is the motor turning? There are several question that need to be answered before we can start pointing fingers.

I have a 20' center console with a 90 and it will carry 4 adults at about 29 mph. I would think an 80 should be plenty for your boat.

Durwood

 

[EazzeO]

Re: Power Issue?

Hey
I would say the boats about 1000 pounds and im not sure of what prop is on it. How do i find out what prop it is? Also like I said it was the end of the season and i didnt get the tach in the dash yet but weather depending im going to get her out this weekend. What would help max rpm or where it doesnt plane out.
Thanks to all.

 

[turbinedoctor]

Re: Power Issue?

If you could get what the max rpm's you are reaching it would help troubleshoot. The prop pitch should be stamped into the hub of the prop somewhere, ie..17, 21 or something like that. The diameter can be measured by measuring from the center of the prop shaft to the outer edge of one of the blades and then double it. If you measure from center of the shaft to outer edge and get 7 then double that you will get 14 which is the diameter. That is if you have a 3 blade prop, if its a four blade prop then measure from tip to tip of oppsite blades.

Also lets us know if you have a 3 or 4 blade prop. That make a difference too.


Durwood