1989 Mercury 9.9 carb size vs. smaller engines

[Bluestream]

I just bought a 1989 Merc 9.9. I also have a 88 Mariner 9.9. I noticed the Mercury has a smaller carb throat size compared to my Mariner. It also shows signs that the carb was taken off at some point. Unless there was a model change between 88 and 89, someone has put on a smaller carb. Externally they look the same.

The Mariner has 3437 & 170 stamped in the carb. The Merc has 3478 with 18B stamped below. Do these numbers hold any clue as to what application the carb was from?

 

[flyingscott]

Put up the serial #s of the motors.

 

[Bluestream]

Put up the serial #s of the motors.

How would that be of any help?

 

[Bluestream]

Put up the serial #s of the motors.

Merc A747585 Mariner A735003 Both Canadian production motors.

 

[flyingscott]

I wanted the serial #s to make sure the mariner was not a yamaha built motor. Somebody probably tried to convert the 9.9 mariner into a 15 hp with a carb swap. The problem with that will be that year 9.9 can't be converted into a 15 hp because the 9.9/15 hp have different blocks that year. That year 9.9 was built on the 6/8 hp block all I can say is take them out and run them and see if the carb works okay on the mariner. It may work it may not. I would bet the smaller carb is the correct one.

 

[gm280]

You could do some research on the web to see exactly what carb blody part number each uses and compare to what you have. That would at least let you know if it the orginial carb or not. There are a lot of marine part break downs and exploded views to see such parts and their part numbers. JMHO

 

[Bluestream]

Flyingscott...The mariner has the original carb on it I've owned it since new ...the Merc has the Smaller carb. Does anyone know if they went to a smaller carb for 89?

 

[ondarvr]

Like gm280 said, look it up on a parts diagram, that's why the serial numbers were needed.

 

[hardwater fisherman]

I saw a site that states the 6,8 and 9.9 hp all used the 18B among others. So maybe it is the size of the jet that determines the hp?

 

[ondarvr]

It is NEVER the size of the jets in carb that determine the HP.

 

[hardwater fisherman]

That is why I added the question mark. I guess I should of said the the 6,8 and 9.9hp may have used the same carb.

 

[Bluestream]

You could do some research on the web to see exactly what carb blody part number each uses and compare to what you have. That would at least let you know if it the orginial carb or not. There are a lot of marine part break downs and exploded views to see such parts and their part numbers. JMHO

I have scoured the web, and have not found a site the gives carb numbers other than part numbers. The numbers I see stamped on the carb are not part numbers

 

[gm280]

I have scoured the web, and have not found a site the gives carb numbers other than part numbers. The numbers I see stamped on the carb are not part numbers

The manufacturing numbers are not necessarily the part numbers the engine company uses as replacement part numbers. You would need to know the real manufacture of the carb to be able to cross it over with those numbers on the part. But if you searched the break down or exploded views and those part number match from one HP size to another, then it is the same carb body. But then you need to see all the other parts and compare as well. JMHO

 

[flyingscott]

IMHO you have a 6 or 8 hp motor with a 9.9 hood. Wouldn't be the first time someone changed the sticker/hood to get more money for the motor. Or somebody put the smaller carb on the motor as a replacement.

 

[Bluestream]

IMHO you have a 6 or 8 hp motor with a 9.9 hood. Wouldn't be the first time someone changed the sticker/hood to get more money for the motor. Or somebody put the smaller carb on the motor as a replacement.

You may be right, I will see if the dealer can match up the serial number and give more info. The guy I bought it from said he bought it new, so it would be a intentional scam if it were not a 9.9

 

[Bluestream]

Called local dealer and they confirmed it is a 9.9. He told me the 6, 8 and 9.9 all use a different carb. I was told the part number for the 6HP carb starts with 95, the 8HP 92, and the 9,9 starts with an 88. My carb shows no part numbers, so this is of no help. I'm right back to square one.

 

[ondarvr]

Check the jets in the carb and match them up with each HP parts list.

 

[flyingscott]

Put up a pic of the motors

 

[Bluestream]

Put up a pic of the motors

Not sure what that would accomplish, but I will post pics of the two carbs...

 

[Bluestream]

Check the jets in the carb and match them up with each HP parts list.

Excellent Idea, I will do that on Sunday