2004 yamaha 4 stroke outboard

[jan joyce]

cannot get the 4 carbs to synch. The #4 is new and runs higher than other 3. What should we do? Thank you.

[pstephens46]

How about a model number? We could guess but with 4 carbs you probably wouldn't be happy.....

[TownsendsFJR1300]

What were the results from the PRIOR THREAD?:

http://www.yamahaoutboardparts.com/f...d-th28809.html


BTW, it'll help to keep THIS issue on ONE THREAD so folks can follow what's been done or NOT..

[jan joyce]

jan joyce

Model number on 2004 50 hp 4 stroke yamaha is T50TLRC. Thank you.

[rodbolt17]

like I said.
a 4 channel manometer and the service manual.
I have done so many that I no longer need the manual on that model.
I do use my tech mate.
basically you use the idle screw on #4 to obtain 1100 RPM.
then you adjust the other 3 shutter screws to obtain the same vacuum as #4. all while keeping the idle speed at 1100.
could it be done with a single channel manometer(vacuum guage) possibly but would most likely take all day.

[rodbolt17]

if you look on the intake manifold you will see a 10mm hex bolt with a copper washer.
that is the test port.
you can use 6x1mm brake bleeder fittings with orings.

[jan joyce]

jan joyce

Thank you. We will do this. I appreciate your help.

[jan joyce]

2004 yamaha 4 stroke carb sync

Thank you for the information. We did this, but #4 is still missing. Is there an inherent problem with #4 carbs on a Yamaha 2004 4stroke 50 hp motor?
The #4 carb is new and the other 3 work fine. Thanks again.

[boscoe99]

If the motor acts the same both with an old carburetor and a new carburetor I might be looking elsewhere for the problem.

There is nothing inherently wrong with the number four carburetor.

[jan joyce]

2004 50 hp 4 stroke yamaha #4 carb

What other areas might be connected with this problem? Thank you again for all your help.

[boscoe99]

What is the motor doing? In the first post you mention getting the carburetors synch'd but say that number four is running higher. Don't know what that really means. In a later post you say that number four is missing.

All carburetors could be properly synch'd yet still one or more may have a miss.

Missing could be spark related, fuel related, compression related, intake leak related...

[99yam40]

And the fact that you (OP)have not said if you even had the proper test equipment to do what you were told to do,
My guess is you do not even have a service manual, which makes me think you do not have the proper equipment either

[jan joyce]

2004 4 stroke yamaha carb problems

Yes, we do have the entire service manual. We have synched the carbs. We have new plugs, a new #4 carb, have new gas line, checked and no vacuum leaks, did compression check 2 times and all even at 150psi,swapped coils 3 times, did value adjustment check, checked gas and put in all new gas, fuel pressure running 4 psi.

The other 3 carbs are fine. It is the number misses both at idle and revving up the motor.

Can you give us some ideas of what it could be such as a sticky value, etc.? and what other things we can do.

Also, can you tell us the what the psi for the fuel pump should be?

It is a 2004 Yamaha 50 hp 4 stroke. Thank you.

[99yam40]

Have you checked spark on all plugs?
have you measured voltages to plugs?
how about to the coils?
why do you focus on the carb?

[jan joyce]

Yes. We put in all new spark plugs. Have a manometer and all checked out.
Not sure if measured voltage to plugs?

No reason to concentrate on cylinder (carb). Just this is where the symptom occurs. That is why we need your help to determine other possibilities.

Presently, the 4th cylinder is misfiring. Thank you.

Swapped coils 3 times and yes, there is a spark on all plugs. Motor is model no. T50TLRC