1999 Mariner 9.9 to 15 conversion?

[lock1nout]

correction

it is a 1991

how simple is this conversion for this motor? just a carb swap or carb + exhaust?

 

[MH Hawker]

Re: 1999 Mariner 9.9 to 15 conversion?

It depends on several things, I did mine over this last winter with very good results, but mine is a 96 and if I remember right around 1995 their is a break of on how their made on parts and so on , perhaps some of the experts will kick in. On mine it was a carb swap. And that reminds me I need to hunt up that thread and post some results.

 

[lock1nout]

Re: 1999 Mariner 9.9 to 15 conversion?

do you mean that it is typically not possible to convert AFTER 95 or before 95 models?

 

[Faztbullet]

Re: 1999 Mariner 9.9 to 15 conversion?

It can be done but you will need to change exhaust tube(bigger) and carb and to see full benefits have exhaust ports raised .100

 

[ondarvr]

Re: 1999 Mariner 9.9 to 15 conversion?

You gave two different years for your motor, you said it was a 99 and then later a 91.

91 no

99 yes

 

[aneal000]

Re: 1999 Mariner 9.9 to 15 conversion?

I have a 1998 Mercury 9.9 that I would love to do the conversion to a 15. I've searched the parts manuals and it does look like the carbs are different:

9.9 - WMC-47A
15 - WMC-49A

The main jet is different, .048(9.9) and .072(15) as well. I've heard some people say it's just the main jet, but based on the parts diagram the butterfly is a different part number for the two motors so I would suspect the bore of the carbs are different as well. Everything else looks like it is the same on the two carbs.

But when I get to the exhaust "tube" I'm lost. Does this need to be changed on my motor? I see where they have a Design I and Design II - and a parts bulletin that I can't find anywhere. The Design I shows different diameter exhaust tubes 1" i.d. for 9.9 and 1 1/8" i.d. for 15. Design II doesn't show any differences for the motors. Design I are also no longer available. Any way to find this parts bulletin #94-3? Or to know if I need to do anything here on mine?

 

[Star]

Re: 1999 Mariner 9.9 to 15 conversion?

It isn't just jets, the venturi and the butterfly are larger. Good Luck!

 

[ondarvr]

Re: 1999 Mariner 9.9 to 15 conversion?

Jets are NEVER the only difference. The reason the jets are different is because of other changes made to the motor to create more HP, changing the jetting is only done to make it run correctly with those other changes.