I need some experience .

[beerjet]

I swapped an old pump out with a newer , fresher one . The old one was a very old style JC that sounded like it had a bent shaft and it now has a newer JG and I assumed the old pump had an A imp. The fresh one has an aluminum A . I put it in a 21' hallett with a very stock 454 . The motor now revs up past 5k (according to the 35y/o tach) with no problem which it didnt before. It feels like it lost some MPH though . I'm gonna mess with some wedges to see if it frees up a bit.
The only conclusion I can come to is that the old impellor was an AA. What do you guys think would cause these results .
-beerjet-

[Jetaholic]

That's what I would think if your RPMs went up.
Try swapping the impeller with the one in your old jet.

[beerjet]

That's what I would think if your RPMs went up.
Try swapping the impeller with the one in your old jet.
I would really hate to take a fresh pump apart since that would involve some down time .
-beerjet-

[Jetaholic]

Or since you know that your new one has an A, take your old one apart and see if it is in fact an AA. It should be stamped on the impeller somewhere.

[beerjet]

Or since you know that your new one has an A, take your old one apart and see if it is in fact an AA. It should be stamped on the impeller somewhere.
There in lyes the problem . It doesn't say anything. I tryed to measure it but the phockin shaft is in the way to get an accurate measurement.
-beerjet-

[Jetaholic]

I tryed to measure it but the phockin shaft is in the way to get an accurate measurement.
-beerjet-
Uh...that sounds like a personal problem dude. :crossx:

[flatassbroke]

What impeller should I be running in my 77 Tahiti ski boat? The 455 never lacks for power or seems like its overloaded, is there a more agressive impeller I could be running? I dont know what is in it now, is it possible to see through the inspection hole?

[sleekcrafter]

Check the tach, would be the first step. The fact you upgaded pumps means nothing, the newly installed pump could be loose, out of tollerance, and the impeller could be worn. You need a few more pieces to the puzzle to get your answer, and yes the impeller could be an A, but it's not likely you pull more then 5k on a stock motor. good luck

[flat broke]

As stated above, you're pissing in the wind on this one. You need to measure the old impeller (I don't see how the shaft would be in the way of a set of calipers), measure the new impeller in the new pump, the verify the clearances in the new pump. The pump being "fresh" shouldn't mean that it will cost you anyting to check these things. Pull the bowl and check the clearances.
Assuming your tach is resonably accurate, I'd bet that the "A" that is supposedly in the fresh pump is either loose or undersized. A stock 330hp 454 won't pull 5k on a tight "A" impeller that is loading well.
Chris

[beerjet]

my "new" pump came out of my other boat which does have more HP and worked perfectly and only has a season on it with little use . I really dont care how much RPM it pulled . I'm more concerned with the fact that is slower. It's not a hot rod anyways but I lost MPH and that's my concern.
-beerjet-

[Duane HTP]

You can spend a week asking questions here and you won't get the right answers because nobody knows what you have.
You would be better off spending your time taking the damn pump apart, look inside and find out what is going on. Then we can help you.
Not trying to be a smart-ass, just trying to make a point!!!!

[beerjet]

So . Let me get this straight . Somewhere between a perfectly functioning y/o pump with an A impellor is removed and then installed in a boat that had an at least 35 y/o pump with a bent shaft . Something has gone wrong to where disassembly is required to the newer pump. :confused: I am in no way the smartest guy in the world but that dont seem right . I am also not a pro. So what the hell do I know .
-beerjet-

[flat broke]

So . Let me get this straight . Somewhere between a perfectly functioning y/o pump with an A impellor is removed and then installed in a boat that had an at least 35 y/o pump with a bent shaft . Something has gone wrong to where disassembly is required to the newer pump. :confused: I am in no way the smartest guy in the world but that dont seem right . I am also not a pro. So what the hell do I know .
-beerjet-
This is exactly the reason so many people have stopped posting in this specific forum. You came in with a question, multiple people, one of which is a person who makes his living helping people just like you, advised that you should first take stock of what you actually have. At that point the answer may become self evident, or at least you would have enough hard data to get better responses here. Instead, you (the guy who's asking for input) question the professional advice that you got for free because you'd rather talk around the problem on the internet than go turn the wrench and find out what you actually have. Like Duane, I'm not trying to be a dick, though I'm sure I'm coming off as one. But the fact of the matter is that until you know what you have inside the pump in the way of clearances and impeller sizes, anything anyone says in answer to your question is just speculation.
Now as for why the boat was faster before with the old pump, there are a couple of possibilities:
The "new" pump is loose.
The "new" pump has a smaller impeller than advertised.
The "new" pump isn't sealed properly at the handhole or suction housing gasket and is sucking air allowing it to spin up, but effectively moving less water.
The "old" pump had some blueprinting work done that was allowing it to operate more efficiently.
Those are all posibilities, the first two can be physically verified, so that's where I'd start.
Now as far as you statement about not caring about RPM, in a jetboat RPM is a very telling bit of info, that when compared with a measurement of work (in the case of these boats a GPS'd speed would be good) can give you a good indication of the overall efficiency of a pump. Especially in a situation like this where the drag reference point(hull) is a constant and you are swapping pumps into/out of the boat. You've taken a pump out of a small boat and dropped it in that big Hallett (I'm making an assumption here). So if the pump was a little loose, or the impeller was smaller than advertised, or the pump is sucking air, it will be far more noticeable when trying to move a heavy boat as opposed to a smaller one. With this many variables in play, it is easy to see why you want as much solid/verified information as possible. That is why people are telling you to check the actual size of the impellers, as well as their respective clearances in their pumps.
Again, I'm not trying to be an A$$hole, but you actually have to get in and nail some of this stuff down before anyone can give you a response worth a damn.
Chris

[DUECE'SDAD]

This is exactly the reason so many people have stopped posting in this specific forum. You came in with a question, multiple people, one of which is a person who makes his living helping people just like you, advised that you should first take stock of what you actually have. At that point the answer may become self evident, or at least you would have enough hard data to get better responses here. Instead, you (the guy who's asking for input) question the professional advice that you got for free because you'd rather talk around the problem on the internet than go turn the wrench and find out what you actually have. Like Duane, I'm not trying to be a dick, though I'm sure I'm coming off as one. But the fact of the matter is that until you know what you have inside the pump in the way of clearances and impeller sizes, anything anyone says in answer to your question is just speculation.
Chris
Very well put man, not tacky at all but truth indeed .

[beerjet]

I want to first say that I dont work at a machine shop or claim to be a machinist of any kind and dont have a facility readily available so calipers are out of the question . I ask these apperently stupid questions so that I can learn something and not just be some check book boater . I dont remember the thread starting with "You better give me all the correct info or else" either . I do appreciate everything everyone says to try and help me with my problem . I'm not a pro and I dont know everything and unfortunatly I require a little schooling on certain things.
I dont have a problem with sending off a pump to be redone to the proper specs since today at 7:23pm I was enlightened by one of the people I was actually hoping would chime in said to. Just because he said so doesnt mean I understand why either so pardon me for being a dumbshit.
Anyways , no offense was taken . I was just lookin to see if this had happened to anyone and what there experience was . Since the old pump is already apart , I'll have the ss imp. checked for size and replaced in the JG pump correctly .
-beerjet-

[Jetaholic]

I want to first say that I dont work at a machine shop or claim to be a machinist of any kind and dont have a facility readily available so calipers are out of the question . I ask these apperently stupid questions so that I can learn something and not just be some check book boater . I dont remember the thread starting with "You better give me all the correct info or else" either . I do appreciate everything everyone says to try and help me with my problem . I'm not a pro and I dont know everything and unfortunatly I require a little schooling on certain things.
I dont have a problem with sending off a pump to be redone to the proper specs since today at 7:23pm I was enlightened by one of the people I was actually hoping would chime in said to. Just because he said so doesnt mean I understand why either so pardon me for being a dumbshit.
Anyways , no offense was taken . I was just lookin to see if this had happened to anyone and what there experience was . Since the old pump is already apart , I'll have the ss imp. checked for size and replaced in the JG pump correctly .
-beerjet-
Hey Omar...just a few questions for ya (OK so the answers are for me but...lol):
1) Which boat did the "new" pump come out of(Make, Model, Size)?
2) Which boat did the "new" pump get installed into(Make, Model, Size)?
3) What motor is in the boat that the "new" pump came out of?
4) What motor is in the boat that the "new" pump got installed into?
5) What was the RPM/Speed ratio on the boat that the "new" pump originally came out of?
6) What is the RPM/Speed ratio on the boat that the "new" pump is now installed on with the new pump?
7) What was the RPM/Speed ratio on the boat that the "new" pump is now nstalled on with the original pump?
8) What is the complete model number of the original pump?
9) What is the complete model number of the "new" pump?
10) Have either of these pumps had ANY rework of any kind? If so, which ones and what was the work done?
Jon

[beerjet]

Hey Omar...just a few questions for ya (OK so the answers are for me but...lol):
1) Which boat did the "new" pump come out of(Make, Model, Size)?
-18' saguaro
2) Which boat did the "new" pump get installed into(Make, Model, Size)?
-Hallett210
3) What motor is in the boat that the "new" pump came out of?
-As far as I know it's a 454 , iron heads , mech. cam. HP?
4) What motor is in the boat that the "new" pump got installed into?
-Very mild 454
5) What was the RPM/Speed ratio on the boat that the "new" pump originally came out of?
-RPM"S were 5000 , low 70's (I dont have GPS)
6) What is the RPM/Speed ratio on the boat that the "new" pump is now installed on with the new pump?
-It stops pullin around 4500 .
7) What was the RPM/Speed ratio on the boat that the "new" pump is now nstalled on with the original pump?
-Same but it feels noticably slower. (again I dont have a GPS)
8) What is the complete model number of the original pump?
-JC-A-H-SS
9) What is the complete model number of the "new" pump?
-JG-A-A
10) Have either of these pumps had ANY rework of any kind? If so, which ones and what was the work done?
-As far as I know the old one has had the edges on the imp. and the bowl cleaned up as well as the new one . I'll send ya some pics as soon as I get the "new" one apart.
Jon
-beerjet-

[flat broke]

This is classic.
The boat "feels" slower.. but no measured speeds to indidcate such. The boat feels slower because it's bigger. It's kinda like going 60 in a shifter cart vs going 60 in a cadillac. Welcome to owning a daycruiser. I'm not baggin on ya cause I own one too. :) The pump probably spun a little better in the Saguaro because of a little more HP and possibly a different loader setup that was blocking a little water. When you moved that pump over to the Hallet, you put it behind a softer engine, and more importantly made it try and move a whole hell of a lot more weight. The boats might not be that far off in top speed, but the Hallet is going to feel slower because it wont plane out as fast, and wont have that pull that a lighter boat will. Also, you're surrounded by more boat and probably don't "feel" as much of the water. It's similar to doing 100 in a 26' Cat and doing 80 in an 18' jetboat. If there wasn't a GPS to tell you otherwise, 9 times outta 10 you'd swear the jetboat was going faster if the two werent running side by side.
Some friendly advice, don't worry about speed too much with the cruiser in general, unless you have a specific speed goal you want to achieve. In which case, get yourself a GPS and get a baseline with the same information you provided here and you'll have tons of suggestions on how to get to where you want to be.
We weren't bangin on ya for information to be hardasses, just to have a good base of information to make an informed recommendation. Just enjoy the boat and don't worry so much about what you feel. Let the numbers tell you what you need/want to know.
Chris

[beerjet]

Yeah , I know I have to get GPS for some hard numbers. My "fresh" pump is gonna get redone anyways for a ss impellor and the bowl on it is another thread in it's self. The rock grate is has , has got to go too. It's just with several trips in the hallett , I wasn't expecting any kind of gain with the pump swap . I definately wasn't expecting it to feel noticeably slower.
-beerjet-

[Brooski]

Some great answers. One thing Omar, when you ask a question on here, you won't get half azz answers. You will get replies from people with alot of knowledge and experience, that are eager to help out increasing the knowledge of fellow boaters. But, they will not speculate or answer when they don't have all the pieces of the puzzle. I have received awesome advice on here, thus resulting in my boat performing much better than I ever expected. Chris really has nailed it, there are so many variables involved. Both pumps were more than likely specifically set up for each boat, and might be less efficient when changed to a different size and weight boat. I compare it to choosing a camshaft without regard for engine size, compression, or load. Good luck. If your not racing or worried about top speed, just sit back, enjoy the ride, and have a beer. :cool: