HOOK??

[slated36]

I had a post on earlier about a 69' Canam.
Well, i took her out for a spin today and noticed that as soon as i got the RPM's up to
5000 that it would start to porpoise. The water was glass a true speed freak could not pray for a better day to be on the water in a death trap. So i would back off and try to ease into it and slowly bring the tail up and the RPM's, same thing. Tail all the way down and it would not do it but then again it would only run 4500. So i have gone back through the posts of the past for this problem and i keep reading about looking for "hook" i am not familiar with this term therefore i have no idea what to look for on the boat. by the way it is a 1969 Canam, 20 foooter, and 454 BBC. so any info is appreciated.
Thank You,
Slate

[squirt]

It's not too hard to check for hook. take a straight edge about 6' long and put it up against the bottom of your hull starting at the transom. You might have something to worry about if you have more than 1/8 inch of gap under the straight edge you either have hook or rocker. Hook will show gap foward the transom and rocker will show gap at transom. I'm not sure what you mean about lowering the tail unless you mean rooster tail. If you run a straight edge and find no problems then you might look into your center of gravity ( too much weight forward or aft.)

[BigDaddy]

Originally posted by slated36:
I had a post on earlier about a 69' Canam.
Well, i took her out for a spin today and noticed that as soon as i got the RPM's up to
5000 that it would start to porpoise. The water was glass a true speed freak could not pray for a better day to be on the water in a death trap. So i would back off and try to ease into it and slowly bring the tail up and the RPM's, same thing. Tail all the way down and it would not do it but then again it would only run 4500. So i have gone back through the posts of the past for this problem and i keep reading about looking for "hook" i am not familiar with this term therefore i have no idea what to look for on the boat. by the way it is a 1969 Canam, 20 foooter, and 454 BBC. so any info is appreciated.
Thank You,
Slate
Hey slate it sounds like you have trim tabs the way you posted your question so if you do it sounds like this is were I would start to look if you do have them but what Squirt Said is another problem you may have as well but you need to just look and try best way to solve it sounds like a weight problem as well hope this helps.
BigDaDDy

[HBjet]

Chet, you might want to offer some advice since you've been removing your hook....And we all would like to know how it's comming.
HBjet

[slated36]

No trim tabs, when i mentioned tail meant rooster. I ended up not buying the boat because as i talked with the owner today when i returned it to him he had mentioned of hull work that had been done. The people who did it were good i am sure but i also did not like the way they utilized the space in the passsenger area.