Vanguard 16hp dies under full throttle, fuel pump?

[1happydude]

So I finally tried taking my manco deuce for its first ride with the new 16hp vanguard vtwin.

I am able to drive around but the engine dies when I hold full throttle. I can go full throttle on flat surfaces for about 50ft before it dies. It will die out if I get it rutts or rough trails.

I am not an expert but I am leaning towards a fuel pump issue. I put a new fuel line and filter, with clean gas.

Should the fuel filter have air in it or should it be full of gas? I tried running a fuel line straight to the pump with the same shut off.

Otherwise the engine starts right up and sound's great.

 

[bob58o]

My inline fuel filter is mostly filled with gas I think. There might be some air in it, hard to recall?

Are you using the stock carb? Does it come with a fuel pump or did you add it?

 

[1happydude]

I got the engine off of a pressure washer. It had the fuel pump and tank with it.

I am going to test the fuel pump today to see if I am getting a good flow.

---------- Post added at 01:35 PM ---------- Previous post was at 01:23 PM ----------

The gas tank has a petcock so it's tough to see if the gas is flowing.

 

[chancer]

Speaking of the gas tank. simple check to start, Try running it with the cas cap loose. Maybe the tank vent plugged not allowing gas to flow correctly.

 

[1happydude]

I think it's my idle gas mixture. I will post a video asap to show the issue. I might just bring it to a repair shop.

 

[OzFab]

First things first, post pics of your kart & setup...

 

[bob58o]

I think it's my idle gas mixture. I will post a video asap to show the issue. I might just bring it to a repair shop.

Idle mix will have little to no effect when running at WOT.

My guess is main jet size is wrong or fuel delivery issue like has been mentioned already.

 

[anderkart]

It will die out if I get it rutts or rough trails.

Your engine has a low-oil sensor. It'll kill spark anytime it "thinks" your oil level is too low...

These oil level sensors function perfectly fine on stationary engines like generators or even on riding mowers, but very typically cause the symptoms your experiencing on gokarts where the oil is much more apt to momentarily slosh around inside the crankcase from the G-forces of cornering or riding over rough terrain.

Something super easy you could try as an experiment is to simply unplug your low oil sensor. Then just always double check to make absolutely sure your oil level is always full before riding.

You'll find Briggs low oil sensors pics and info at this link:
http://outdoorpowerinfo.com/repairs/briggs_low_oil_shutdown.asp

PS: I've had serveral karts with pulse fuel pumps, they've all had bubbles in the fuel line between the pump and carb, thats normal

 

[mindymogul]

Is it an electric fuel pump with a vacuum primer or is it a full vacuum one? Usually what'll happen is the lil' diaphragm in the assembly rots out due to modern gas. I have a '92 16hp Vanguard on a '77 MTD 990 that ran gas from back in '95. At WOT, it'll get enough suction to pull the flap into the inlet and clog it. About a $5 fix from any Tru-Value or Agway. Another thing could be the low oil sensor as addressed, or it could be some form of internal tilt safety cut-off. I had a couple Kohler engines that have those.