New Boat Purchase

jaybirdnwa

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Apr 9, 2012
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I am looking at buying a 2005 Chaparral ski boat with a 4.3 litre Mercruiser 190 hp inboard/outboard. I have been told that this boat was originally bought with a 3 litre mercruiser in it and was swapped out for a 4.3 litre after 35 hours of use. I am going to meet the guy at the lake tomorrow for a test drive. What do I need to look for?
 

Fun Times

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Re: New Boat Purchase

The first thought that comes to mind is did he switch out the gear ratio in the stern drive or did he try and make it work with a different size propeller.

Typically boats do not seem to perform as well as expected when changing out the propeller vs the gears.

Try Googling the boat with V6 power to see about how fast it should run and get some overall specifications.

Good luck.
 

jaybirdnwa

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Re: New Boat Purchase

The model is a 2005 Chaparral 180 ssi. So I'm not real sure if the new 4.3 litre is compatible with the outdrive or if the outdrive was replaced also but will ask.
 

achris

More fish than mountain goat
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May 19, 2004
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27,468
Re: New Boat Purchase

The drives are the same, just the gears inside have a different tooth count.... So it's quite possible the PO changed the engine and left the original drive, with the original gears, on and just used a bigger prop to control the WOT revs....

Chris........
 

jaybirdnwa

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Apr 9, 2012
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Re: New Boat Purchase

Ok, so I will ask if the gears were replaced at the time of the engine. And if they were not, will this increase the wear and tear on the boat? Is this and expensive fix if I choose to purchase the boat and then change out the gears myself?
 

stonyloam

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Re: New Boat Purchase

The 3.0 with the gen II should have a 2.0 or 1.94 ratio. The 4.3 should have a 1.81 ratio. You should be able to locate the serial number and gear ratio on the upper port side of the outdrive upper housing. If you don't have the correct ratio for the 4.3 you will want to take that into consideration before buying the boat. You wouldn't necessarily change out the gears, you would likely change out the whole driveshaft housing (upper). Either case it won't be cheap.
 
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Bondo

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Re: New Boat Purchase

Ok, so I will ask if the gears were replaced at the time of the engine. And if they were not, will this increase the wear and tear on the boat? Is this and expensive fix if I choose to purchase the boat and then change out the gears myself?

Ayuh,... Welcome Aboard,... You can buy a fresh brand new Upper with the right gear ratio right here at iboats for 'bout $800....

Changin' the Merc gears in yer drive to the Right Merc gears would come to that much or More, parts, 'n labor,...
 

jaybirdnwa

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Apr 9, 2012
Messages
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Re: New Boat Purchase

Thanks for the advice everyone. My wife and I went and looked at the boat and the first thing that I looked for was the gear ratio stamped on the outdrive which it had 1.81 stamped on it. So we bought the boat and are anxious to use it. Thanks Captain for the advice.
 

Fun Times

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Re: New Boat Purchase

Glad to hear it all worked out for you!

Happy safe boating.:)
 

fat fanny

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Feb 9, 2006
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Re: New Boat Purchase

So did the previous owner gab in the motor mounts himself?
 

jaybirdnwa

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Apr 9, 2012
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Re: New Boat Purchase

The boat was taken back to the dealer and it was installed professionally. My kids and I have already been skiing behind it and it runs like a new boat.
 

agallant80

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Oct 25, 2010
Messages
2,328
Re: New Boat Purchase

I have seen the motor swap at the marine a few times. It starts with someone swapping out their 5.0 for a 5.7 then there is a low hour 5.0 on the market so the guy with the 4.3 puts the 5.0 in his boat and the guy with the 3.0 puts the 4.3 in his boat.
 
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