1997 SLT 700 FUEL Delivery problem?

[awdunn]

".....Thought it might be lean because of a fuel delivery restriction, so I put fuel in a glass jar and hooked it up and it did the same thing, so I don't think it's a leak in the fuel tank sender or fuel/water separator. "

-- So, probably not a problem caused by the fuel system - but by something else [evidenced by same issue when run off a jar of premix.]
So... resolution? I have same problem with 96 SL 700 - either bogs and quits, or runs away, using either boat fuel system or jar of premix... [out of water, not tested in water.]
-- Any runaway is always a lean condition ... so always caused by an air leak somewhere??
-- 96 SL/SLT does not have reed box gaskets - gaskets are moulded into each side of reed box flange. They appear ok.. but has anyone solved a leak issue by adding a gasket?
-- Leak testing crankcase appears laborous and maybe cost prohibitive, considering value of this boat.
-- I can see where an internal check valve could cause a lean condition at idle [air siphons backwards thru main jet into low speed jets] but mine appear ok. [3rd party rebubild kit, ugh.]
-- Suggestions? Ideas?

[sdlvx]

Curious if you ever got these issues resolved?

It's very common for the fuel water separator to be kind of clogged and cause just enough restriction to go a little lean. Clean it very often, a few times a summer at least.

[WKUalum]

Ok, well that's one problem that shouldn't be there, thank you. It was a very wet mist/large drops that I could see coming out. I assume liquid in there could block the pulse pump pulsing and make it not pump fuel.

I would assume the engine would be running rich then lean as it couldn't pump fuel any more? When I first got it started it fired out a ton of black oil then cleared up. I guessed most of the old fuel in the crank was gone then, I'll try draining it after the reeds are out.

Thanks

Curious if you ever got these issues resolved?

[K447]

It is possible there is water inside the engine. Not a good thing, but possible.

Investigation is advised.

[Wordupward]

Ok, well that's one problem that shouldn't be there, thank you. It was a very wet mist/large drops that I could see coming out. I assume liquid in there could block the pulse pump pulsing and make it not pump fuel.

I would assume the engine would be running rich then lean as it couldn't pump fuel any more? When I first got it started it fired out a ton of black oil then cleared up. I guessed most of the old fuel in the crank was gone then, I'll try draining it after the reeds are out.

Thanks

[K447]

There should not be much if any liquid inside the crankcase. Liquid spurting out of the pulse fitting is not what you want.

Sometimes there is a small amount of 2-stroke oil puddled in the crankcase, but typically not more than maybe a teaspoon or two, at most.

There should never be liquid gasoline in the crankcase, more than maybe a condensed droplet or two.

I suggest you inspect whether there is pooled liquid in the engine, if so, suction it out through the intake after removing the reeds.

The old-school method is to remove all the spark plugs and crank the engine, which should blow liquid out the plug hole. If it really is gasoline in the engine, the fuel fume plume poses a real fire hazard. Especially with the spark plug wire ends firing away.

The pulse hose should never have liquid inside, nor should the fuel pump pulse side.

[Wordupward]

Also, I pulled the pulse line off and cranked the motor to at least see if it had some pressure and some fuel was spraying out of the nipple on the bottom of the case. Is that normal? I assumed a little would be in there because it's tapped into the crank.

[Wordupward]

No, the reeds were not inspected, I wasn't sure it that could cause this, I'll inspect those.

Compression isn't great 97pto 105 mag

Pulse hose is new, I changed it, feels good and hooked up to pump on carb.

I know it needs at least a top end soon, but I was making sure I didn't start there when it could be a fuel pressure problem, or make sure I had all the parts if I needed to do the bottom end at the same time.

[K447]

Did you remove and inspect the intake reeds?

Cylinder compression check?

The fuel pump depends on the pressure pulses from the crankcase.

Pulse hose is not floppy flexible or aged stiff?

All fuel hoses and pulse hose are connected to the correct places?

[Wordupward]

Recently bought a 1997 SLT 700 that wasn't running. Previous owner said it was having fuel problems, he hooked up an electric pump to solve the problem (horrible I know) and flooded the crankcase. So I rebuilt the carb, added a new gasket and diaphragm to the pulse pump, replaced the pulse pump line, replaced the fuel line and return line, and finally got it started. Took it to the water and it ran for 4 or 5 minutes sometimes it would rev and run away then died.
The previous guy added a clear fuel pump and I could tell it wasn't pumping any fuel through it as it cranked on the starter. Took it back home, tried to start it on the trailer and it started, but if you added throttle, it would rev and not stop (lean runaway?). Thought it might be lean because of a fuel delivery restriction, so I put fuel in a glass jar and hooked it up and it did the same thing, so I don't think it's a leak in the fuel tank sender or fuel/water separator.
Thinking I need to do a crankcase leak test to see if it's leaning the engine and possibly making the pulse pump not work because of lack of pulse in the PTO cylinder crank.

Does anyone have any tips on blocking off the intake and exhaust ports? I assume I pressurize it through the pulse pump fitting? Easiest way to pressurize it to about 10psi? Bike pump schrader fitting somehow?