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More HP Out of a 4 Stroke 80

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fikey13

New member
I have a 2002 Yamaha 80HP 4 stroke with a jet lower. It is a 4 cylinder and MAY be, according to one boat mechanics I spoke to, the same basic block as the 90 and 115HP. I am trying to get a little more oomph out of it. Does anyone know if there is a cost effective way to increase the HP or is this just a foolish idea? Thanks.
 
Is hundreds of dollar cost effective?

The 2002 F80 and F100 share a number of common parts. But a few differences. Find out the differences and add up the total for parts.

Could be just jets. Could be carburetors.

Then add labour.
 
Hundreds of dollars WOULD be worth it. Thousands would not. The 20 extra HP would really help. Trying to find someone knowledgeable to give me a definitive answer is the hard part.


boscoe said:
Is hundreds of dollar cost effective?

The 2002 F80 and F100 share a number of common parts. But a few differences. Find out the differences and add up the total for parts.

Could be just jets. Could be carburetors.

Then add labour.
Click to expand...
 
Find a set of 100 HP carburetors on E-bay.----Install and smile from ear to ear.----Why are you running a jet ?-----Shallow water ?
 
Yes. Some parts are very shallow. Do you know as a fact that the only difference is the carbs or is that just a guess? A service tech at the local Yamaha dealer told me he didn't know what was the difference and could be stuff like cams and such. ?? I guess my hope was to find someone who actually KNOWS what the difference is.
 
A service tech at a YAMAHA dealer does not know ?------Send some beer tokens -----or perhaps look on --boats.net-----All the parts / pieces are there and just a click on the part # to see what years / models it fits !!!
 
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fikey13 said:
Yes. Some parts are very shallow. Do you know as a fact that the only difference is the carbs or is that just a guess? A service tech at the local Yamaha dealer told me he didn't know what was the difference and could be stuff like cams and such. ?? I guess my hope was to find someone who actually KNOWS what the difference is.
Click to expand...

It is all layed out in the Yamaha parts catalogs. Available to you at www.yamahaoutboards.com
 
Boscoe,
Hate to appear dumb as a rock, but I clicked on your link and couldn't find anything on the upgrade. I also called Yamaha directly and they said they have no information on upgrading it. I am not saying you are wrong, I just can't find it.
 
You are not dumb. You just don't know what you are doing. Not yet anyway.

Did you not find the parts catalogs for the 2002 F80 and 2002 F100?
 
Once you get to the the parts catalogs, open each similar illustration for each model. F80 to F100.

Using the illustration labeled "Intake", see below what is to be seen. No changes whatsoever between the F80 and the F100.

Now in some illustrations you will find different part numbers. The illustrations labeled as "carburetor 1" for example.

Remove the F80 peculiar part numbers and install the F100 peculiar part numbers.

 
Not only did the service tech at the Yamaha dealer "not know", I called Yamaha directly and they said they didn't have any information on it.
 
fikey13 said:
Not only did the service tech at the Yamaha dealer "not know", I called Yamaha directly and they said they didn't have any information on it.
Click to expand...
Exactly right. I would not expect them to know.

Guys answering the phone at Yamaha are not usually trained to know about such matters.

And if they know I would not expect them to share that information.

Yamaha USA that is.
 
fikey13 said:
Not only did the service tech at the Yamaha dealer "not know", I called Yamaha directly and they said they didn't have any information on it.
Click to expand...
That is because it is illegal to modify an outboard in the states made after 1996. So you will be hard pressed to get an answer from anybody. It is all up to you to do the legwork.
 
Illegality aside, Yamaha US is in the business of distributing motors and spare parts. They are simply not in the business of providing motor modifications and/or engineering services for same.

Same with the other motor makers.
 
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