Yamaha 115tlrs 2 stroke fuel to cylinder problem

yftcaptdan

Cadet
Joined
Oct 27, 2010
Messages
8
I have a 01 115 tlrs 2 stroke I just got. When it was tested during buying the engine started right up. 130 compression across the board as well. Once I got it home and tried to start, it was hard to start and wouldn't idle. I had to give continuous gas to keep going and it had that bogging sound. I figured dirty carbs so I proceeded to clean the carbs. I did find many clogged jets and almost a jelly in the bottom bowl. I also cleaned out the fuel filter and checked the fuel pump for any ethanol crystals. I also drained all the gas since it looked cloudy and brown. I put fresh gas in and installed a fuel water separator. Now it seems there is some kind of back pressure and gas will not get to the cylinders. I pumped the primer and could tell the carbs had fuel in them but the bulb felt odd like it had air pushing back on it. It didnt feel fuel hard. i would unhook and hear a pop of air escaping. I sprayed ether into the cylinders the motor fired but would die as soon as the ether was gone. What could be holding the fuel back from entering the cylinders? Some kind of vapor lock in the vac line? Any thoughts are much appreciated. thanks.
 

Natty Light

Petty Officer 2nd Class
Joined
Jun 11, 2012
Messages
120
Re: Yamaha 115tlrs 2 stroke fuel to cylinder problem

Is your fuel line on backwards? There should be an arrow on the bulb pointing in the direction it should flow.
 

multimech

Petty Officer 1st Class
Joined
Apr 26, 2012
Messages
386
Re: Yamaha 115tlrs 2 stroke fuel to cylinder problem

Agree with Natty as to the fuel primer bulb.

However, your problem is not getting fuel to the cylinders, it is getting fuel to the carbs. Take the fuel lines off the carbs and squeeze the primer bulb. If you have fuel coming out of the fuel lines to the carbs, then your problem is in the carbs. Needles not going off their seats. Float levels wrong.

Check this ONLY after you have determined that the primer bulb is on correctly.
 

yftcaptdan

Cadet
Joined
Oct 27, 2010
Messages
8
Re: Yamaha 115tlrs 2 stroke fuel to cylinder problem

The fuel line on wrong? I'm not an idiot.
In fact I did find the problem on my own and the motor is running great now. There was a clogged AIR jet on 2 carburetors. It is always the carbs right?!! I thought I cleaned them well but apparently I missed this spot. On top of the carbs is a large brass screw that shows a compartment with 4 holes into the throttle body and as well as the air needle screw. I had to use a piece of copper wire to clean and an impact screwdriver just to loosen that huge screw. I had fuel in all the carbs before but the clogged air jets kept fuel from leaving and entering the cylinders. It also affected the feel of the primer bulb. I knew before I turned the key after the second cleaning that something was different after the ball got fuel hard. I appreciate the help even if it was not helpful.
 

boscoe99

Lieutenant Commander
Joined
Aug 22, 2013
Messages
1,785
Re: Yamaha 115tlrs 2 stroke fuel to cylinder problem

The fuel line on wrong? I'm not an idiot.
In fact I did find the problem on my own and the motor is running great now. There was a clogged AIR jet on 2 carburetors. It is always the carbs right?!! I thought I cleaned them well but apparently I missed this spot. On top of the carbs is a large brass screw that shows a compartment with 4 holes into the throttle body and as well as the air needle screw. I had to use a piece of copper wire to clean and an impact screwdriver just to loosen that huge screw. I had fuel in all the carbs before but the clogged air jets kept fuel from leaving and entering the cylinders. It also affected the feel of the primer bulb. I knew before I turned the key after the second cleaning that something was different after the ball got fuel hard. I appreciate the help even if it was not helpful.

Thank you for being an azzhole even though you are an azzhole.

Maybe only an idiot would clean carburetors and over look part of the job.

You may find most of your problems by looking in the bathroom mirror.
 

Natty Light

Petty Officer 2nd Class
Joined
Jun 11, 2012
Messages
120
Re: Yamaha 115tlrs 2 stroke fuel to cylinder problem

Glad you found the issue. Please make sure the key is in the ignition before attempting to crank your now running outboard
 
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