03 40hp yamaha starting problem

[Piz]

Hi,

I've got an 03 40hp yamaha I'm having trouble with. The boat has been sitting for almost a year, the carbs clogged up last year and I've just got around to working on it.

I rebuilt/cleaned the carbs - all new gaskets, float/pin/seat and also replaced the jets. Also got rid of all the old gas, cleaned out the fuel lines and fuel filter in the motor - the gas lines in the motor were changed out about 2 years ago and they are not hard/brittle. Changed the fuel filter between the tank/motor.

When I put the carbs back on the motor started right up, ran for a couple minutes and cut. Now I can't get it to start back up, it acts like it is not getting fuel.

When i pump the ball to get it hard I am noticing that on the top and bottom carb when I pump the ball I get gas overflowing out of the top vents - Is this indicating that the new float pin is sticking or not sealing?

I've also played around with the red switch on the middle carb, trying to crank it with that in different positions - got it to start up once with it in the up position, but it died again after about a minute like it was not getting fuel again, then got it to start with the red switch in the middle(normal) position and got it to start after several attempts, but same result.

Another note about this motor, if it matters. It used to be oil injected, but that has been disabled and it just runs a premix.

Any tips would be appreciated

 

[99yam40]

Re: 03 40hp yamaha starting problem

on my C40TLRX 1999 the red switch rotated in the counter clockwise position is in normal , middle position is open, and full clockwise is off.
Are you sure about yours?

Fuel pump could be bad (not pumping)and any trash that was in the pump and lines when you put the cleaned carbs back on maybe what has caused floats to not close off the needle and seats and is flooding the motor.


Did you follow the link and sync steps in the service manual after installing the carbs?
Needs to be done every time

 

[Piz]

Re: 03 40hp yamaha starting problem

Thanks for the reply 99

I took the carbs back off to see why the pins were not sealing. ended up having to bend the little tab on the float just a hair as the pin would not make a good seal even with me holding the float all the way up. After that I put them back on and she started right up and is idling like a champ on the hose. Crossing my fingers that it runs as good when I get a chance to test it on the water.

I did not do the link and sync and I don't have a manual. If you happen to know how to do it for a 2003 40TLRB please let me know. Not sure if I need to though, I didnt really mess with any linkage other than popping the one off the 3 carbs and it went back on just the same.

Thanks

 

[Piz]

Re: 03 40hp yamaha starting problem

You're right about the red switch too, thanks.

 

[99yam40]

Re: 03 40hp yamaha starting problem

I recommend picking up a Yamaha service manual for your motor if you plan on working on it your self

Here is a thread where Rodbolt gave me some info on link and sync, hope it helps you http://forums.iboats.com/showthread.php?t=366637