Do they rate top speeds of boats when new?

[_chris_]

I am trying to find out how fast my boat was when new compared to now just to get an idea of horsepower lost and probably some water soaking in my stringers and floor. My boat is the 1972 Glastron V-177 Swinger with the AQ130C 270. Every time I go out I get a different speed, I have taken it out twice this year and the first time I reached 29 MPH at 5,000 RPM and yesterday I reached 27 at 5,000 RPM, I am also wondering if my boat ever broke 30 MPH in its life(I am sure it has at some point). I have tried trimming up my outdrive and it changed nothing.

 

[QC]

Re: Do they rate top speeds of boats when new?

There is some data out there, but probably not anything very good for something that old. The only thing you can really do is maximize what you have and you can compare to similar setups that guys might have here.

 

[_chris_]

Re: Do they rate top speeds of boats when new?

There is some data out there, but probably not anything very good for something that old. The only thing you can really do is maximize what you have and you can compare to similar setups that guys might have here.

Thanks QC, I am gonna take it out a couple more times before I bug anyone for set up issues and I do have another prop that I have not run yet(the PO said it was worse than the one on the boat) but I would like to check it out. Next weekend I am heading up to Big Bear with it but I don't know how the elevation is going to affect my testing.

 

[QC]

Re: Do they rate top speeds of boats when new?

Next weekend I am heading up to Big Bear with it but I don't know how the elevation is going to affect my testing.

My experience was 4 inches of pitch with a 140 I/O. 6500 ft is pretty tough. I would not base any decisions on data I got there unless I was going to run there more than 50% of it's life. Even if you're going once a year you'll need a different prop and carbs probably need to be re-jetted if you go more often than that.

 

[_chris_]

Re: Do they rate top speeds of boats when new?

My experience was 4 inches of pitch with a 140 I/O. 6500 ft is pretty tough. I would not base any decisions on data I got there unless I was going to run there more than 50% of it's life. Even if you're going once a year you'll need a different prop and carbs probably need to be re-jetted if you go more often than that.

Big Bear is where it will spend most of it's time, My brother owns two slips and one is always empty(Out for rent to me for a case of beer a weekend). I grew up there and my whole family lives there still. The only other real lake I go to is Lake Mohave, and Lake Elsinore just for testing things. Does anyone sell kits for rejetting? I have rebuilt and cleaned carbs just never messed with the jets. When you says 4 inches of pitch how do I measure it?