Convert a Mariner 9.9 into a 15?

[KenLodato]

Hello everyone,

Thanks for taking the time to read my thread. I recently fixed my 9.9, and would like to go a little faster with my 14ft tracker jon boat and I was curious as to what exact 15hp parts would be compatible with my 9.9? It is a Mariner 9.9ML 682C 361494. Any feedback and suggestions would be much appreciated. Thanks and happy holidays everyone!

I was also considering trading my mariner 5hp and 9.9 for a 15hp + on craigslist http://miami.craigslist.org/brw/boa/3504709682.html but I'd much rather keep both the motors and possibly convert the 9.9 to a 15hp.

 

[MH Hawker]

Re: Convert a Mariner 9.9 into a 15?

I am in the process of doing the exact same thing to a 1996 mariner 2 stroke 9.9, While I can only speak about my particular motor it seams to be a very simple conversion. What I did was to sit down one evening and go over both motors part by part and compare part numbers, exhaust chambers, mid sections, motor block, piston and rings, intake and reed valves and carburetor. in my case their was only one different part number. The main jet in the carburetor. And in my case I ordered a brand new carburetor just to make it a simple swap out job. The boat is winterized right now but will see how it works in the spring.

I went the new carburetor route because the total of a complete rebuild on my old crab including a fuel pump and enricher is about 25.00 less than a brand new one.

 

[Faztbullet]

Re: Convert a Mariner 9.9 into a 15?

The main jet in the carburetor. And in my case I ordered a brand new carburetor just to make it a simple swap out job

On your model the carb is different as the venturi and throttle plate are larger along with jet, just hope you didnt buy another 9.9 carb

I was curious as to what exact 15hp parts would be compatible with my 9.9?

Yours is a Yamaha badged engine and only difference is reed stop gap/carb jet and some models timing. The 9.9 reed stop is set at 2.9-3.1mm and the 15 sets at 3.9-4.1mm, set timing at 25?+/-1? . The hard parts to find are the main nozzle and jets...

 

[KenLodato]

Re: Convert a Mariner 9.9 into a 15?

What I did was to sit down one evening and go over both motors part by part and compare part numbers, exhaust chambers, mid sections, motor block, piston and rings, intake and reed valves and carburetor. in my case their was only one different part number. The main jet in the carburetor.

I don't know what motor I would be looking at compatibility for? Unless the motor I found below would suit, it does say it is in the 6e7 series in which I have. If this is the correct motor, I will compare part numbers this evening to identify what i need.

Yours is a Yamaha badged engine and only difference is reed stop gap/carb jet and some models timing. The 9.9 reed stop is set at 2.9-3.1mm and the 15 sets at 3.9-4.1mm, set timing at 25?+/-1? . The hard parts to find are the main nozzle and jets...

1986 15ELJ Yamaha Outboard **Its not letting me post a Boats DOT NET link for some reason, so add the boats DOT NET link in front of the rest of this link and it will bring you to yamaha 15 model /parts/search/Yamaha/Outboard/1986/15ELJ/AIR CLEANER-CARBURETOR (9 - 9 - 15H)/parts.html

Do you think this is compatible with my mariner 9.9? I am seeing they offer both 9.9 and 15 carbs on these later Yamaha models. If so, I see they have the value and carb available. Any thoughts or advice would be greatly appreciated!

 

[MH Hawker]

Re: Convert a Mariner 9.9 into a 15?

Fazebullet

I realize this is also one of the things that pop up ever so often and on a lot of the OMC motors it is as simple as a carb change but not necessarily on a merc/mariner, and not to muddy up kens thread but this is what I have been looking into my self.

I ordered a 15 hp carb just in case their was some other differences I wasn't seeing and to have a new fuel pump and enricher that's all part of the carb.

my motor is a Canadian made 1996 mariner ser 0G119661

the 15 hp carb is a........13929726T5
the 9.9 carb is a...........13928846A17

 

[Faztbullet]

Re: Convert a Mariner 9.9 into a 15?

Do you think this is compatible with my mariner 9.9? I am seeing they offer both 9.9 and 15 carbs on these later Yamaha models. If so, I see they have the value and carb available. Any thoughts or advice would be greatly appreciated!

Looks like it will work...

I realize this is also one of the things that pop up ever so often and on a lot of the OMC motors it is as simple as a carb change but not necessarily on a merc/mariner,

Any time you up hp there is a change in the carb, either the venturi is larger(in your case) or the molded in emulsion tubes and nozzles are different sizes. You are correct on the part numbers of the carb you ordered but you can see that there is a size difference as the throttle shutters and shafts (#2 and #3) are different part numbers.
Mercury Marine 9.9 HP Carb(9.9/15)(USA-S/N-0G112450/BEL-S/N-9831800 & Up) Parts

 

[MH Hawker]

Re: Convert a Mariner 9.9 into a 15?

Yea its never as simple as it looks and why I thought it best to change it all out.

 

[KenLodato]

Re: Convert a Mariner 9.9 into a 15?

Well I just picked up a 1998 yamaha 15HP and it runs like a champ. I did make a mistake due to my excitement. I used my 50:1 gas/oil ratio tank and my 15hp only takes 100:1. do you think this would cause the motor to stall out and run improperly. I got up to plane, everything seemed fine, about 1/2 mile out and it started stalling so i had to doggie paddle back home, lol. I am now running it in a bucket of water with 100:1 and it seems to be running fine, but I wanted to see the pro's opinions before i risk going out fishing. Thanks everyone and happy new year!!

Ken

 

[Maxz695]

Re: Convert a Mariner 9.9 into a 15?

You where running more oil than nessecary and it may have fouled the plugs. Shouldn,t have hurt anything. Give it another try and it should be ok. If in fact it calls for 100:1 ratio

 

[KenLodato]

Re: Convert a Mariner 9.9 into a 15?

Thanks for your feedback, I agree with you, I ran to gas station and added more gas to make it 100:1, at first it was stalling, but once i burned out the old gas/oil, it ran for an hour and half straight without any stalls or signs of problems. I posted in the yamaha section and everyone basically said no it shouldn't of stalled out but only more smoke, but i ran to gas station anyways and seems to be good. I will go fishing tomorrow and see how everything goes.

 

[Maxz695]

Re: Convert a Mariner 9.9 into a 15?

OK Good luck with the run.

 

[KenLodato]

Re: Convert a Mariner 9.9 into a 15?

I went out fishing today, everything seemed fine, went 6 miles out to the ft lauderdale inlet and it gradually slowed down while i was in full throttle, until it completely stalled. So i played with the choke and got it started up, and it's only about 20% of what it was previously going in full throttle.

I have a video, I will have uploaded by tonight, it slows down in full throttle from 20% of the normal speed to 5%, getting even slower so i lay off the throttle then back on and so on. The compression is 120/120 in the cylinders, peeing normal, motor isn't hot and the throttle isn't the issue, as i checked it manually to test if it was stuck or broken, in which it wasn't. Also i found out its not a 1998, its a 1993. I appreciate any feedback or solutions, thanks all.

Ken

 

[Faztbullet]

Re: Convert a Mariner 9.9 into a 15?

Fuel restriction, fuel pump diaphragm, trash broken loose in carb restricting high speed jet or possible electrical issue... my personal bet is going to be in the carb.

 

[KenLodato]

Re: Convert a Mariner 9.9 into a 15?

Thanks for your suggestions, once the rain stops today, I am going to remove the carb to check. The guy I got the motor off said he cleaned the carbs, etc, but i am finding it hard to believe anything he told me now. The fuel pump diaphragm seems to be in good shape. Do you think its possible a spark plug went and i was running on one cylinder? Thanks again for your help.

Here is the video, i am sorry there is no audio, but you can see it going around 20% of normal speed in full throttle, but then it gets even slower. http://www.leadest.com/yamaha.mp4

 

[KenLodato]

Re: Convert a Mariner 9.9 into a 15?

I just looked at the motor now and the spark plugs seem to be getting hot and melting the wire attached to them and im noticing oil coming out of the top one.