'94 75HP Yamaha 2-Stroke Outboard

[jabig3low]

Hey everyone!
Ok.. My buddy gave me a boat with said engine on it. I have replaced/rebuilt everything in it. New fuel tank, fuel hoses, fuel pump, rebuilt all carbs, fuel filter etc.. Initially it started and would shut off after the fuel from the bulbs ran out. I diagnosed that as the fuel pickup from the tank, replaced it, and now... it doesn't crank at all..

Additionally, there is fuel dumping out of the carbs (without it running). I just took the carbs off to check the carbs for gunk or the float sticking. Everything looked good, but I'm still getting fuel coming out of the carbs..

PLEASE HELP!!!

 

[boscoe99]

Fuel out of the carburetors is indicative of a float valve not sealing.

If you jumper battery power to the starter motor relay will the motor crank?

 

[boscoe99]

There is no 1994 75 Yamaha.

Do you have a C75TLRS perhaps?

I know adding those extra letters are a killer but they are needed.

 

[jabig3low]

There is no 1994 75 Yamaha.

Do you have a C75TLRS perhaps?

I know adding those extra letters are a killer but they are needed.

Yes, that's it. The guy at the boat shop told me '94, so that's what I went with

 

[jabig3low]

Fuel out of the carburetors is indicative of a float valve not sealing.

If you jumper battery power to the starter motor relay will the motor crank?

Yes. The starter is good. It started and ran (until fuel ran out of the bulbs) prior to the gas tank change.

 

[boscoe99]

In your first post you said it won't crank. Now you are saying that it will crank. (I think).

When you turn the key to the start position what actually is happening? 1. Nothing, 2. the motor cranks but won't start, 3. the motor cranks and starts but won't run or 4 ???

 

[jabig3low]

In your first post you said it won't crank. Now you are saying that it will crank. (I think).

When you turn the key to the start position what actually is happening? 1. Nothing, 2. the motor cranks but won't start, 3. the motor cranks and starts but won't run or 4 ???

Thank you for your help.

In the beginning it started and ran until the fuel in the carb bulbs ran out. Now it's your #2.

I just took the carbs back off and checked the float valves. They are all free of debris and when I put air to the fuel line they are all giving me some resistance like they should.

 

[boscoe99]

Use the primer ball to fill the carburetors back up. The motor should now start. And run. Presumption being the carburetors are no longer leaking gasoline.

If the motor runs and then dies from lack of gasoline then the fuel pump may not be doing its job. Or perhaps there is a flow restriction between the motor and the tank.

 

[jabig3low]

Use the primer ball to fill the carburetors back up. The motor should now start. And run. Presumption being the carburetors are no longer leaking gasoline.

If the motor runs and then dies from lack of gasoline then the fuel pump may not be doing its job. Or perhaps there is a flow restriction between the motor and the tank.

So I just started it today a d after about 1 minute there was gas pouring out of the carbs again.

 

[jabig3low]

Use the primer ball to fill the carburetors back up. The motor should now start. And run. Presumption being the carburetors are no longer leaking gasoline.

If the motor runs and then dies from lack of gasoline then the fuel pump may not be doing its job. Or perhaps there is a flow restriction between the motor and the tank.

So I just started it today and after about 1 minute of it running there was gas pouring out of the carbs again. It then died from flooding I assume.

 

[99yam40]

You will need to find out where that gas is coming out.
is it out of the vents on the carbs?
if so the float is not closing off the flow thru the needle and seat, which causes the bowl to over fill and come out the vents