2006 115 fuel starved!

[Starling00]

Have a 2006 115 that is struggling to stay running unless someone is pumping the bulb. Carbs are clean, fuel pump has been replaced, all fuel lines in have been replaced and the tank pressure is fine. When the motor has fuel pumping into it, it runs like a top.

I'm a novice at this, so go easy on me - but what am I missing??

[Joe Reeves]

You say that the fuel pump has been replaced BUT the engine will only run if someone constantly pumps the fuel primer bulb.

If this is correct, either the new fuel pump is faulty or the pressure stroke of the piston coming down doesn't exist.

Remove the spark plugs OR simply remove the plug wires from the spark plugs... you DO NOT want that engine to start while you're checking it out!

Remove the pressure hose that leads to the crankcase temporarily. Crank the engine over to observe the pressure being forced out of that hose. It should be quite a blast.

If you haven't already removed the spark plugs, do so and take a compression reading of all individual cylinders. What are those psi readings of all four cylinders?

[tcnoithat8]

Have a 2006 115 that is struggling to stay running unless someone is pumping the bulb. Carbs are clean, fuel pump has been replaced, all fuel lines in have been replaced and the tank pressure is fine. When the motor has fuel pumping into it, it runs like a top. I'm a novice at this, so go easy on me - but what am I missing??

BÃ*i viết rất chi tiết, hy vá»�ng ná»™i dung của nó chân thá»±c vÃ* sâu sắc hÆ¡n nữa, mình kết bạn vá»›i bạn nhé.

[Starling00]

Joe will be testing compression tomorrow. Quick couple of questions. I'm also replacing the vst gasket - anything to be mindful of? Second, lot of black gunk oozing out of the exhaust inside the pump and the lower unit. What is that stuff, where is it coming from?

[Joe Reeves]

You have a year 2000 engine... I retired in 1991. What is a "VST"?

Black gunk is the soot lining the long exhaust housing being washed down by unburnt fuel.

What do the cylinder numbered spark plug electrodes look like? Standing in back of the engine, facing the spark plugs, the cylinders are numbered as follows:

2....1
4....3

[Starling00]

Joe - had a guy with a lot of motor experience listen today, he said the compression is fine. Pulled the plugs, he said they looked too wet. You familiar with this issue? The motor is a 2006. Vst is apparently where mixing of fuel/oil happens.

[Starling00]

vapor fuel assembly gasket

Found a minor split in the gasket of the vapor fuel pump. Membrane looked fine, the tear in the gasket was very clean and small but assume big enough to cause a problem.