How to determine what pilot jet is for 9.9 HP and wich is for 15 HP?

[andreipou]

Hello,

Carb for my motor has 2 Pilot jets listed:

82600M (#46) and 94561M (#48)

I am not able to fid any indication what is for 9.9 or 15 HP.
I do have original service manual and parts list, but nothing there.

Internet does not say it either.

Please help.

Tnx.

 

[jimmbo]

Well the second # shows up as a NLA jet for a Mercury. Doesn't say which engine, Since there a several types of 9.9, and 15hp. things like a Serial Number can narrow the search.

If you are thinking a Jet change will change a 9.9 into a 15, forget it.

 

[boscoe99]

Hate to bother you but would it be too much trouble for you to tell us the brand/model/year of the motor?

 

[andreipou]

 

[boscoe99]

The larger jet will be used on the larger motor.

For instance, a 1984 Yamaha 9.9 uses a #52 pilot jet. A 1984 Yamaha 15 uses a #56 pilot jet. Would be similar for your 1983 Mariner.

I suspect you will find a 6E8 marking on your carburetor. That is the Yamaha code for a 1983 15CE carburetor.

 

[andreipou]

It is hard to see markings on carb now since I put it back after complete cleanup.

According to the manual this motor comes with 2 types of carb:

1. Uses jets #52 and # 56 (not mine ,uses very long about 3'' jet )
2. Uses jet # 46 and #48 (mine, uses about 1/4'' long jet)

I ordered #48 using same logic as you mentioned (bigger number for bigger motor), but now just trying to confirm that because it was just my guess, no documented proof for that.

I am having problems adjusting carb now , so need to eliminate possibility of using wrong jet.

Tnx.

 

[andreipou]

P.S.: I forgot to mention that engine came with missing pilot jet, that was why I had to go thru the troubles figuring out what the correct one is. I had another thread for that. And this is my first Yamaha, I had 7 OMCs and one Mercury before.

 

[boscoe99]

Yamaha's methodology is to sometimes use one parts catalog for two different models, when those two models share the vast majority of parts. The 9.9 and 15 are one such example.

If you look at the 1984 parts catalog for a Yamaha 9.9 (or a 15) you will see what I am talking about. Yamaha includes note to differentiate when the parts are different. For instance:

 

[andreipou]

So, looks like #48 is correct jet for 15 HP, right?

 

[andreipou]

I do have problem making it run:

I starts instantly with closed choke and runs very fast even with handle turned all the way to slow.
As soon as you try to open choke it just stops.

Any idea?

Thanks.