optionslvtr

The boat also has bottom paint on it,, how much is that slowing it Down???

Too Stroked

Unless it's an unusually horrible job, probably less than a mile or two an hour.

optionslvtr

This weekend I noticed that the manifold had wet spots around it,,,and about 4 of the bolts were finger loose.. looks like I need a new manifold gasket.. was I loosing a ton of power because of this?? I tightened them down out on the water and drove it back in noticing no difference.. should I also do cap and rotor.. my Rpms I got up to 4900 this weekend but I'm still nowere even near at least 60 m.p.h...... I will also be doing a compression test this week to see were I'm at with that on each cyclinder. I'm no

BBCLiberator

iTrader: (2)

The numbers don't make sense: assuming you have a good prop and are spinning a 23" prop to 4700 rpm that comes out to 60mph almost exactly, assuming a 12% slip and 1.5 ratio number you may be a little higher than that for slip... Are you reading the rpm's off the factory tach? Going to a 25" prop isn't going to do you any good I don't' think. Need to get accurate #'s first...

http://www.rbbi.com/folders/prop/propcalc.htm

BBCLiberator

iTrader: (2)

Agree. something doesn't make sense, even if it's overweight...

optionslvtr

I am reading this off the factory tach,, and the prop is definately a 23 pitch mirage.. what is the slip?

BBCLiberator

iTrader: (2)

Ok, if you have a 23 pitch prop (some people say inch) of you spin it one revolution through something solid it would move 23 inches. Obviously you are in water that moves so it has some "slip". Slip is good as long as it is not to much, you would like less than 15%. By your numbers it shows you have way to much slip or the prop is messed up or something is wrong, that is what I mean when I said the numbers don't make sense.

Many things affect slip, diameter of the prop, # of blades etc.

Reason I asked about the tach is they are notoriously wrong, maybe you are turning less rpm than you think. If the boat was water logged or something you shouldn't be able to turn the same rpm. I'm not saying that couldn't be contributing to the issue either. I would expect a water logged boat to turn less rpm, my boat won't turn the same rpm with 6 people on it as it will with 2 people.


Hope that helps.

FIXX

iTrader: (2)

soyoue running a boat still with gas smell and a loose exhaust manifold..man i sure hope your boat dont expload...

does the prop look to be stock in appearance? is their still cup in the blades? so the rpms went up and the mph did not,,i wqould start looking at the coupler spun,,engine is misaleigned(look at the bottom nuts on the motor mounts to see if they loosened and ??)

optionslvtr

The boat has a brand new coupler I installed a few weeks ago , I spun the original one last year.. everthing is aligned perfect, I used the tool and everthing. As for the prop it does show a lot of age and some nicksanalong with being corroded.. but it is a 23 pitch mirage for sure. The boat has always ran well. Should i think about getting a new prop? I will be doing new cap and rotor, fuel filter, this week. Should I try a new prop?

optionslvtr

I will post some pictures of the boat and prop tommarow,,aslong as I figure out how to.. I am new to this website