Looking to replace 4 cylinder to 6 cylinder

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mfd2698

Seaman Apprentice
Joined
Aug 2, 2006
Messages
39
Is there anything I need to replace besides the engine such as pumps, outdrive or can I just drop a 6 in and go?

Thanks
 
A

arrkerr

Petty Officer 2nd Class
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May 7, 2009
Messages
105
Re: Looking to replace 4 cylinder to 6 cylinder

From which 4 to which 6? I would guess that if the boat had a 6-cyl option, you could drop in one of those 6s. The big problem is mounting it. I'm not sure if, for example, a Merc 3.0 mounts in the same way as the same year Merc 4.3 (anyone know?). Being enough room is another problem, but I think most engine compartments are big enough.

I also think that the 6cyls usually had power steering, which is optional on a 4cyl. Not sure how much that really matters though.
 
M

mfd2698

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Aug 2, 2006
Messages
39
Re: Looking to replace 4 cylinder to 6 cylinder

The boat had a 6cyld option but the original owner did not want to spend the extra 1500 for it or wait an extra week to get it. The engine compartment looks like it has enough room but I am worried about how much it is going cost. if it is just the engine I can pick one up for realitivly cheap. It is the extras that worry me.
 
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mfd2698

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Messages
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Re: Looking to replace 4 cylinder to 6 cylinder

By the way, it is a chevy engine with a Yamaha outdrive.
 
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fishrdan

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Re: Looking to replace 4 cylinder to 6 cylinder

You're missing 1 important piece of info, what year & mfg? Are you trying to go from a 4cyl to an I6 or V6, and are the years compatible? The outdrive has a different ratio between the 2 engines too.

If you can get a complete drive train from a donor boat I'd say it's a possibility, but if you just have the bare V6 engine it's going to be expensive hunting everything down you will need, drive, manifolds, Ypipe, mounts, etc, etc...

I think it would be better to find a 6cyl boat than to try and do a 6cyl swap, but anything is possible.
 
M

mfd2698

Seaman Apprentice
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Aug 2, 2006
Messages
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Re: Looking to replace 4 cylinder to 6 cylinder

fishrdan said:
You're missing 1 important piece of info, what year & mfg? Are you trying to go from a 4cyl to an I6 or V6, and are the years compatible? The outdrive has a different ratio between the 2 engines too.

If you can get a complete drive train from a donor boat I'd say it's a possibility, but if you just have the bare V6 engine it's going to be expensive hunting everything down you will need, drive, manifolds, Ypipe, mounts, etc, etc...

I think it would be better to find a 6cyl boat than to try and do a 6cyl swap, but anything is possible.
Click to expand...

I thought it would be to expensive. Like I said before this is my first I/O, I am used to outboards, take one of and put another on.
 
Don S

Don S

Honorary Moderator Emeritus
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Aug 31, 2004
Messages
62,321
Re: Looking to replace 4 cylinder to 6 cylinder

mfd2698 said:
By the way, it is a chevy engine with a Yamaha outdrive.
Click to expand...

Don't even waste you time and money on a conversion. Yamaha IO's were only used for a few years in the late 80's early 90's and other than CaptKen that visits these forums, not many parts or service is even available.
You are also out of the relm of outboards. Even they aren't throw away anymore.
 
M

mfd2698

Seaman Apprentice
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Aug 2, 2006
Messages
39
Re: Looking to replace 4 cylinder to 6 cylinder

Nobody is getting rid of the older outboards anymore due to the cost of buying new. I was thinking about replacing the yamaha with a merc outdrive but again, cost is becoming a major issue now a days. I am looking for a economical way out which I have not found yet.
 
Bondo

Bondo

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70,526
Re: Looking to replace 4 cylinder to 6 cylinder

mfd2698 said:
Nobody is getting rid of the older outboards anymore due to the cost of buying new. I was thinking about replacing the yamaha with a merc outdrive but again, cost is becoming a major issue now a days. I am looking for a economical way out which I have not found yet.
Click to expand...

Ayuh,... Here's the Best answer, Right here,...
If you can get a complete drive train from a donor boat I'd say it's a possibility,
Click to expand...
 
B

betayv

Senior Chief Petty Officer
Joined
May 13, 2008
Messages
706
Re: Looking to replace 4 cylinder to 6 cylinder

if you are going to change the outdrive look for the transom assembly on ebay you probably found a nice one and for a good price, I found one for a 6 cyl from a 2006 boat the complete transom and outdrive for 1000$ great deal my engine is a v8 so I cant use it.
 
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