2000 40hp Johnson no fuel flow

[guy48065]

Another spring, another problem preventing me from getting my boat in the lake.

Engine was running just fine when I put it up late fall, but won't start today.
Fuel flow from tank, thru bulb, and thru filter has been verified but the engine will only start on ether. Also there's no fuel spurting from the primer lines.

What is the path of fuel flow from the filter on? The factory service manual doesn't include a diagram of the fuel system.

I'm just baffled what's preventing pressurized fuel from getting to the primer lines (and carbs), either by electric priming or by manual bypass on the solenoid. Something seems to be blocking all flow beyond the filter.

 

[jakedaawg]

The pump is after the filter...

 

[guy48065]

Would the pump prevent primer fuel getting through?

 

[jakedaawg]

Not supposed to. Take a fuel line off a carb, squeeze bulb, does fuel come out?

1st, check to verify that the arrow on the bulb is pointing to the motor.

 

[guy48065]

Nothing new here... Like I said it was running great last season.

I had to reattach the pulse hose 2 years ago. It's getting soft after (then) 17 years. I'm thinking possibly it has developed a leak. BUT the motor should still fire & run on what's already in the carb bowls.

AGAIN--I can't find a fuel system diagram. You know--like is found in EVERY car & truck repair manual ever published. There's 10 pounds of crap stuffed into a 5 pound housing--all painted black--impossible to follow. I'd like to troubleshoot on paper before I start taking it apart again.

 

[jakedaawg]

From the cowl connector there are two lines. One oil, goes directly to pump. One fuel, goes to the filter then to the pump. Coming out of pump is one line to a plastic manifold and a tee. The manifold splits to the two carbs. The tee splits to the primer solenoid. From the solenoid are two small lines going to the behind throttle plates of carbs or to the intake, however you want to describe it. It's just that simple. You do realize the primer solenoid is just a valve? No fuel will come out if either the motor is not spinning or someone is not actually pumping the bulb. Pull a fuel line from the carbs or the large one at the solenoid. Squeeze bulb. Does fuel come out? That's the 1st step. I am not gonna draw a diagram and figure how to post it...

 

[guy48065]

My boat is 200 miles away at my cottage so I was wanting to "work it out on paper" before heading back this weekend. Once I get there it's about 50 miles to any sort of marine supply.

Previously if I pulled a primer line off a carb and pressed in the key I would get a stream of fuel that shot 5 feet. Now not a drop.
I would also expect that once the motor fires off ether it should pull fuel out of the carb bowls whether the pump is functioning or not--until dry. It runs about 2 seconds till the ether is gone.

Unless the bowls are already empty.

 

[guy48065]

I found the parts diagram shows what's connected to what--but the actual hose routing is a mystery. I just have to assume it's correct on my motor (i'm the 3rd owner) and it's perfectly normal to have to remove the starter to gain access to most of them.

 

[guy48065]

Primer hose tips plugged.
Carb bowls full of oil.
Fuel pump pulse hose leak.

Replaced soft hoses with new.
Chased out primer tips with a tag wire.

Fires right up. But I have another problem. I had a slight fuel leak last spring that I couldn't find so I rebuilt the carbs in case the leak was fuel overflow from worn inlet needles. Probably was not needed because the leak is now bad enough that I can see seepage at the nipple connection to the VRO pump inlet. So now I need to take the damn thing all apart again after I get those parts.

I think next springs project is going to be to remove the VRO pump & replace with a standard pump & just pre-mix from that day on. Even though my pump hasn't been a problem, I've now spent so much time under the hood that I've really grown to hate that thing and how hard it is to access the connections, and how cramped it makes everything. What little trust I had for it is gone.