1987-91 merc 8, 9.9, 15 same motor? diff carb?

[dkonrai]

curious the merc late 80's-90's 8, 9.9, 15 hp series motors. if i have a 8, can i just swap out the carb and then have a 15? sorry for the ignorance, but i usually have little white or blue motors.
thanks
dino

 

[Faztbullet]

Re: 1987-91 merc 8, 9.9, 15 same motor? diff carb?

if i have a 8, can i just swap out the carb and then have a 15?

Sorry but no, through some years do share the same displacement the 15 is ported different,tuner is bigger, carb is bigger and some years.

 

[achris]

Re: 1987-91 merc 8, 9.9, 15 same motor? diff carb?

You just found the most amazing little 8hp, 27 years old and never run, now you want to bastardise it.... :facepalm:

 

[wired247]

Re: 1987-91 merc 8, 9.9, 15 same motor? diff carb?

You just found the most amazing little 8hp, 27 years old and never run, now you want to bastardise it.... :facepalm:

Face Palm? Seriously? 8 HP. I'd be pumping nitrous into that thing already.

 

[dkonrai]

Re: 1987-91 merc 8, 9.9, 15 same motor? diff carb?

You just found the most amazing little 8hp, 27 years old and never run, now you want to bastardise it.... :facepalm:

hehehe no, its for a different motor. looking into a 91, basically the same motor? hmmm ohno im starting to collect them little mercs too
i just wondered. the other brand, you just slap on a different carb and go. guess the mercs are different. and why are the carbs so complicated?
dino

 

[achris]

Re: 1987-91 merc 8, 9.9, 15 same motor? diff carb?

hehehe no, its for a different motor. looking into a 91, basically the same motor? hmmm ohno im starting to collect them little mercs too
i just wondered. the other brand, you just slap on a different carb and go. guess the mercs are different. and why are the carbs so complicated?
dino

ok... Sometimes it is just a matter of putting another carb on, but sometimes they also change things like ignition advance, reed openings and porting. I also know that on some of the 15s there is even a different exhaust horn....

As for complicated carbs???? Have no idea what you mean... The carbs are about as simple as they get! The only 'complication' is that the fuel pump is sometimes built into the side of the carb...

Chris.......

 

[dkonrai]

Re: 1987-91 merc 8, 9.9, 15 same motor? diff carb?

ok... Sometimes it is just a matter of putting another carb on, but sometimes they also change things like ignition advance, reed openings and porting. I also know that on some of the 15s there is even a different exhaust horn....

As for complicated carbs???? Have no idea what you mean... The carbs are about as simple as they get! The only 'complication' is that the fuel pump is sometimes built into the side of the carb...

Chris.......

the carb float setting can be challenging to say the least. and yes the carbs have the fuel pump and primer. too much plastic. ever rebuild a omc? tin can with a hole in it
dino

 

[achris]

Re: 1987-91 merc 8, 9.9, 15 same motor? diff carb?

the carb float setting can be challenging to say the least. and yes the carbs have the fuel pump and primer. too much plastic. ever rebuild a omc? tin can with a hole in it
dino

Many...

Merc carb float setting is easier than an OMC... OMC requires a special OMC gauge with different heights for different engines. Lose that gauge and you're screwed. Merc, just set the float level, with a ruler, and the float drop, with a ruler... Just like you would with any other normal carburettor... No need for any special gauges...

Cheers.....

 

[MH Hawker]

Re: 1987-91 merc 8, 9.9, 15 same motor? diff carb?

Several of the 1995 to 2000 just need a carb swap, the others are complicated.

 

[dkonrai]

Re: 1987-91 merc 8, 9.9, 15 same motor? diff carb?

Several of the 1995 to 2000 just need a carb swap, the others are complicated.

how about the 1991? can i just do a carb swap? looking at a 1991
thanks
dino

 

[MH Hawker]

Re: 1987-91 merc 8, 9.9, 15 same motor? diff carb?

About the only way of finding out is to take a parts manual for a 9.9 and a 15 and sit down and compare part numbers for ever piece in the power head and exhaust. A quick reference is the bore and stroke and CC ratings.

 

[dkonrai]

Re: 1987-91 merc 8, 9.9, 15 same motor? diff carb?

About the only way of finding out is to take a parts manual for a 9.9 and a 15 and sit down and compare part numbers for ever piece in the power head and exhaust. A quick reference is the bore and stroke and CC ratings.

thanks, i guess is have some homework i believe the bore/stroke/pistons and crank are the same. will research a bit more.
dino

 

[ondarvr]

Re: 1987-91 merc 8, 9.9, 15 same motor? diff carb?

Just go to the top of the page and look at the stickies, it has the manuals for small mercs. I didn't check it again, but that year 6, 8 and 9.9 are the same displacement with other changes, the 15 has a larger displacement. Nothing you can do about that. In about 94' the 9.9 and 15 became the same displacement.

 

[aneal000]

Re: 1987-91 merc 8, 9.9, 15 same motor? diff carb?

Bringing up an old thread, but I just picked up a 1998 9.9 for an inflatable and would love a touch more power if it is as easy as changing the carb and exhaust. Where can we find manuals on these so I can look up parts?

 

[aneal000]

Re: 1987-91 merc 8, 9.9, 15 same motor? diff carb?

I found them... very nice.

 

[Scott Danforth]

Re: 1987-91 merc 8, 9.9, 15 same motor? diff carb?

you do realize this is an old post