Yamaha 2003 40hp 2 stroke wont start

kozz22

Recruit
Joined
Jun 14, 2010
Messages
2
Engine will only start briefly if I spray carb cleaner in carbs .

Here is what Ive tried so far.
1. cleaned tank
2. put ethenol free gas in it
3. changed fuel H20 seporator
4. cleaned fuel filter
5. had carbs cleaned
6. My next step was to open up the carbs myself to see what type of work this shade tree carb cleaner did. 2 out of 3 of the main jets I could not open. I knew about 1 from the previous service. It was running fine untill the motor was not ran for about 3 months, hence here I am!
7. With the carbs off I cranked the engine to see what type of fuel stream there was. It did not come out hard or plentyiful.

My question now is
1. How much gas should be pumping out? I bought a new fuel pump but do not want to install unless I am sure.
2. What else should I try?
3. Do I have the carbs rebuilt?

I have another issue with this motor but we will save that for post smooth operation. thanks
 

JB

Honorary Moderator Emeritus
Joined
Mar 25, 2001
Messages
45,907
Re: Yamaha 2003 40hp 2 stroke wont start

First, find out what's wrong. Then fix it. Throwing parts and money at it is a waste.

Go to the Engine FAQs Forum and do "Outboard won't start". Let us know the outcome.
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Yamaha 2003 40hp 2 stroke wont start

replace the pump,its a maint item about every 3 years.
clean the carbs.
make sure the fuel tank and lines are spotless.
make sure the quick connect is working and the rubber oring intact.
by artificially ading a fuel to make it run we know your fuel system is defective.
tst compression first to make sure you havent done any mechanical damage with you spray can.
 

kozz22

Recruit
Joined
Jun 14, 2010
Messages
2
Re: Yamaha 2003 40hp 2 stroke wont start

Finally got it running. To get it to idle smothly via the remote I had to screw the adjustment all the way down. I am talking about the adjustment on the middle carb.

Runs great under way. Now the "HOWEVER", When at idle, in neutral, it will shreik and gives a kick with a cough. There is no real patern with it but will stop doing it if I increas the idle. What do you think?
Michael
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Yamaha 2003 40hp 2 stroke wont start

I think you still have dirty carbs or a rankshaft seal leaking.
 
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