always had allot of prop slip what is the deal

[badbowtie]

I have a 1985 welcraft 210 elite that I just repowered this year with a rebuilt motor from rapido marine I replaced the out drive last year with a sei drive. It has a mercruiser 350 they told me it is 285hp It has the 1.47 drive alpha drive . I am running a 14.25x21P alum prop and I have a hustler 14.25x21p and it is worse the other prop not sure on make. I have so much prop slip it is crazy. At 5,000 rpm I am only going 42mph. At 4,000rpm I am going 30mph This is all using a gps and tach has been tested against two other tachs. I have no idea why I have so much prop slip or what to try with out buying abunch of props.

 

[John_S]

Re: always had allot of prop slip what is the deal

I have a 1985 welcraft 210 elite that I just repowered this year with a rebuilt motor from rapido marine I replaced the out drive last year with a sei drive. It has a mercruiser 350 they told me it is 285hp It has the 1.47 drive alpha drive . I am running a 14.25x21P alum prop and I have a hustler 14.25x21p and it is worse the other prop not sure on make. I have so much prop slip it is crazy. At 5,000 rpm I am only going 42mph. At 4,000rpm I am going 30mph This is all using a gps and tach has been tested against two other tachs. I have no idea why I have so much prop slip or what to try with out buying abunch of props.

Did you verify the sei drive has the 1.47 ratio by turning the engine over by hand 3 revolutions, which should equal 2 revolutions of the prop. Otherwise, start looking for other possible issues such as over-weight boat (water logged foam), etc.

 

[badbowtie]

Re: always had allot of prop slip what is the deal

I have not spun the motor to check it but have had the problem before when I had the the alpha 1.50 drive before it went out. I have no foam I have had all the floors out and replaced all them.

 

[John_S]

Re: always had allot of prop slip what is the deal

I have not spun the motor to check it but have had the problem before when I had the the alpha 1.50 drive before it went out. I have no foam I have had all the floors out and replaced all them.

OK, It looks like a rather typical v hull in your pic. How much does this boat weigh?

 

[badbowtie]

Re: always had allot of prop slip what is the deal

I would say between 3500-4000

 

[John_S]

Re: always had allot of prop slip what is the deal

I would say between 3500-4000

I don't know, untie the anchor, unstrap, the trailer??? I assume you have already been through Don's performance checklist.

While I suspect you will benefit from a stearn lifting prop, vs that Hustler, not that it would make up for all that slip.

 

[badbowtie]

Re: always had allot of prop slip what is the deal

I had the same problem with the same props last year different motor I replaced motor and all other parts carb and ignition and still same problem. I have found two more exact same boats and years and motor combos for sale and one guy has emailed me back saying he has a 19p stainless on his boat and it runs 54mph and the other guy has not answered. I would say maybe I am just flexing/slipping the prop that bad maybe I hate to just start buying them.
It comes out the water quick and easy with out really even using the trim tabs.
I also think I have a old 19P alum prop that just has some small nicks in around the edges that I have never even used came with the a box of junk the guy had 6 years ago.

 

[John_S]

Re: always had allot of prop slip what is the deal

I had the same problem with the same props last year different motor I replaced motor and all other parts carb and ignition and still same problem. I have found two more exact same boats and years and motor combos for sale and one guy has emailed me back saying he has a 19p stainless on his boat and it runs 54mph and the other guy has not answered. I would say maybe I am just flexing/slipping the prop that bad maybe I hate to just start buying them.
It comes out the water quick and easy with out really even using the trim tabs.
I also think I have a old 19P alum prop that just has some small nicks in around the edges that I have never even used came with the a box of junk the guy had 6 years ago.

The speed posted by the other seller would lead me to something else is going on. Did he provide the make/type and diameter?

Are you getting the full range of trim? Once on plane, you should be able to retract tabs and trim up for more speed. Are the tabs mounted too low and always causing drag? check mfg recommendations.

I'd run the 14.25 x 21, assuming it is a standard type prop, while you continue testing. The hustler doesn't provide much lift and is cupped and acts like more pitch.

You are getting plenty of rpms, its like you are dragging something along with you. The hull nice straight and clean?, with no growth build up (didn't look like it in pic), no dips, hooks, or damage?

 

[badbowtie]

Re: always had allot of prop slip what is the deal

The trim tabs are coming all the way up like should and I can trim the out drive up and pick up a couple more mph also. Bottom of boat is straight and does not have growth or anything like that going on. I am going to call the other guy that has the same boat for sale and see what info he can give me.

One of the boats same year and model that i have said he is running a quicksilver 19 pitch stainless steel prop and it runs 54mph at 4600rpm. I do know my timing is up some from the factory since I had to to even make it rev up past 3600. Maybe I am just over propped.

 

[John_S]

Re: always had allot of prop slip what is the deal

The trim tabs are coming all the way up like should and I can trim the out drive up and pick up a couple more mph also. Bottom of boat is straight and does not have growth or anything like that going on. I am going to call the other guy that has the same boat for sale and see what info he can give me.

One of the boats same year and model that i have said he is running a quicksilver 19 pitch stainless steel prop and it runs 54mph at 4600rpm. I do know my timing is up some from the factory since I had to to even make it rev up past 3600. Maybe I am just over propped.

You said you were hitting 5K rpms, so that wouldn't be a sign of over propped. Unless you were ventilating, never would hit that.


It you are going to test another prop, try to borrow a 4 blade, 14.25-14.5 dia, 19-20" pitch or a 15" dia 3 blade in 19-20" pitch. I think those will help, but something else is going on, but I'm running out of ideas.