1987 Johnson 150 GT fuel restriction alarm??

[MMarshall88]

I got a 87 astroglass boat with a 87 Johnson 150 GT that's having the alarm go off. I know it's not the overheat alarm. It has new water pump and head temp on them. I noticed last year my boat would run fine wide open. Then at times the alarm would come on and after a minute or 2 , the engine would start to bogg down. I would look at the primer bulb and it would be sucked in like someone was squeezing it all the tight. I changed every hose going from the tank to the pump. Changed fuel filter and primer bulb. Also checked the valve on the tank to make sure that ball wasn't hung and someone had already taken it out. I also took out the gas tank and drained the tank to make sure there was no debree in there and to make sure the line wasn't clogged as well. I also checked the vent line and all seemed fine. Took it out On the lake for the first time today since last year and it rode fine until we started to head back to the dock from a fishing hole and the alarm came back on. It was a constant beep. Went to check the primer bulb it partially squeezed together and it was like someone was sucking the air out of the it on the other end. It wouldn't release. so I'm not sure what's going on and what it could be. I hope it isn't something leading to the VRO pump going bad. But the pump sucking the bulb down would tell me it still has pressure. I also read something about a vacuum pulse there too. If anyone has any idea what it could be without having to take to a dealer and pay a ton of money. Or if anyone else has any suggestions. Thanks.

 

[Bosunsmate]

Might be the valve in the bulb sticking. Have you replaced the bulb? Install with arrow in direction of motor

 

[henleyhale]

Had an issue like this on my 83 rude, no alarm on it, but the fuel hose in the tank was collapsing and i chucked a dang 40 dollar hose and bulb in it for no reason, i had some good take hose in my garage from god knows what

 

[MMarshall88]

You think this could be the problem then ? May have to take that hose back out and check it.

 

[MMarshall88]

Might be the valve in the bulb sticking. Have you replaced the bulb? Install with arrow in direction of motor

Yep. Just installed new Johnson bulb and Johnson fuel filter.

 

[Bosunsmate]

Yep. Just installed new Johnson bulb and Johnson fuel filter.

Ok then its got to be something from the tank to there.
You said you think the air vent lines ok. Have you tried running with the cap off or loose

 

[emdsapmgr]

When the vacuum switch sets of a constant alarm, you've got really high fuel suction problems. Check the anti-siphon valve on the tank. If you get any debris inside the tank, it can get sucked up into the ball valve and cause the ball to stick. I noticed that on my V6 when running WOT. It was a few hundred rpm short. Found sand inside valve, causing the ball to stick. Took the anti-siphon valve out just for that reason. Problem solved. I found a bandaid stuck up a fuel pickup tube inside a built-in fuel tank for a Mercruiser. Go figure that one... On some cheap hose bulbs, they need to be oriented so that the arrow points in a generally upward direction. If the bulb lays downhill in the splashwell of the boat, the valves can stick, causing high fuel suction, sucking the bulb flat. Always possible that the vent hose to the fuel tank is plugged/restricted.

 

[jakedaawg]

I am gonna assume you replaced the hose and bulb with the 3/8" model and have the arrow on the bulb pointing towards the motor. Try running on a portable tank. That will tell you where your problem is.

 

[MMarshall88]

I took the line off that goes into the tank. It has the anti siphon valve on top. There is no ball in there so the gas should flow through that fine. I checked the line that runs down into the tank. It's a thick plastic hose. I checked it to make sure it wasnt worn out or could be collasping. I tried to squeeze it together but it's so thick and hard that I don't see anyway that the pressure could make it collapse. The hose does have a screen on the bottom of it to keep trash from sucking through the line. I didn't see anything in the tank. I also took off the vent hose and blew through it and it was clear.

And yes I did change all the hoses out with the 3/8 hose and the 3/8 Johnson primer bulb and 3/8 fuel filter. It's weird cause the trip I made yesterday with the boat , we made a 8 minute drive to a spot on the lake and it rode fine. We decided to go to another spot on the lake. That was a 10 minute drive. About the time we got to the spot the alarm started going off. so it does it sparatically at times. I don't seem to understand it

 

[MMarshall88]

The bulb does have the arrow pointing towards the motor. So that should be ok. And it does lay in the splash well. And it looks to be laying downhill some. Maybe I should rearrange it so it lays flat. It's really weird that I can't find the problem. It has to be something simple. When the alarm goes off and the motor Boggs down starving for fuel, when I try to squeeze the bulb, it's stuck together. I can work with it for a few seconds and get it to realese. If the alarm is still going off, whenever I get the bulb to realese and I squeeze it a few times to send fuel to the motor , the alarm will go off. So it has to be something related to these lines and fuel tank. I don't know what else to do besides rearrange the bulb. After that I may have to look into changing the fuel pump or another one or rebuild it or look into replacing it with a newer lower pressure aftermarket fuel pump. I've heard of people replacing it like that. They just have to find the right one that will pump the right fuel to the motor.

 

[henleyhale]

If the primer is collapsing, you dont need a new fuel pump, you still have an issue down stream, sounds more like debris, try a portable tank, every boat needs one for some extra run time. I also ran into an issue once of a fuel tank hose made for a 60 hp motor feeding a 150 and that cause a vapor lock at high speeds, im assuming your boat isnt as rag tag as the models i can afford.
Installing a clear fuel filter that is replaceable and removing the screen in the tank is also acceptable, and you can see the gas in it while you run it and see when its starting to starve, this was very helpful to me when i was dealing with a vapor lock. Best of luck, and dont chuck a 140$ vacuum pump on it its working really well. Vacuum pumps leak fuel and suck air in them when they are bad then the motor sounds like trash, but they dont suck a bulb shut

 

[emdsapmgr]

Re-splice the fuel hose bulb to another spot on the fuel line so that it is pointed uphill all the time. Like maybe inside the back seat area. Agree, your fuel pump seems to be working just fine.

 

[MMarshall88]

I just relocated it inside the tank area next to the tank. So it's at a level area when the fuel comes out. It never goes downhill. I will try the boat out again Saturday and see what it does and get back on here with details.
I have some fuel hose out in my garage. I thought about taking off that plastic hose inside the tank and replacing it with some of that fuel hose. The hose that goes into the tank is about 12 inchs long and it's straight as an arrow. I was wondering maybe if that hose was shifting some and maybe sticking to the bottom of the tank not alowing fuel to reach the bulb. I was thinking of making the hose a little longer so that it lays in the bottom of the tank instead of it pointing straight down.

I will also try loosing the fuel cap some as well if it starts doing it to make sure the tank is venting properly

 

[MMarshall88]

Took the boat back out today. It seemed to do worse this time. The first 10 minutes riding, it was fine then after that it never could open up to WOT without the alarm coming on and engine bogging down. At one point I checked the primer bulb, it was sucked all the way flat as is could be. I repositioned the bubble inside the tank area and also tried loosing the gas cap. Still nothing. I left the motor running with the primer bulb sucked in and I loosened the hose from the tank and the bubble opened back up. I even pulled the hose out of the tank and watched the motor suck up the gas through the tube. So I have no idea what's going on. I guess I'm going to have to take it to a mechanic to work on. For some reason I have feeling the fuel pump is failing. I feel like it has enough pressure to suck the air out of the bubble but not enough to suck the fuel out under pressure. If anyone else has any suggestions. The last thing I might try is a spare gas tank in the back. I might run it on that to see if it changes anything.

 

[1983 ercoa 21']

Try a different tank.

 

[MMarshall88]

I'm trying to think of where I can get or borrow a tank to try. I hate to go buy one. They are like 50 bucks for a 10 gallon tank. I'm wondering if I can take a big gas jug and make a temp tank just to run it on up the the lake in

 

[Fed]

Clean out the old tank.

 

[MMarshall88]

Last year I took the tank off. It did look like a yellowish gel material in the bottom of the tank. I drained the tank completely out and put it back together. I thought maybe that fixed it. But guess now. I'm now debating on getting a new hose that fits into the tank. Something they can lay at a 45 degree angle in there or lay on the bottom. My hose now goes straight down into the tank. I hope it's not sticking to the bottom.

 

[emdsapmgr]

Any chance you can borrow a plastic 6 gallon tank from a friend for testing purposes? That yellowish material may be dried fuel gelatin. The residue of gas after the light liquid evaporates and leaves the gel. New fuel won't dissolve it. You have to use a fuel cleaner, like a gumout product to dissolve it. Usually, the only problems that the fuel pickups have is that they loosen up where they attach to the the tank head. They can suck air there and cause problems. Also, they can get pinholes along their length, causing (poor) suction problems: (air in the fuel) .

 

[MMarshall88]

I'll have to ask around to see if I can get one. I noticed though when that bubble goes flat that I can lossen the hose to where it meets the fitting in the tank and the bubble will open back up like It should be. That kinda tells me that it's something from that fitting down into the tank. But like you said, I need to get a test tank and try it. I also found a forum on here from a guy that shows you how to test your fuel pump and vent hoses with some gauges. I may go ahead and do them just to make sure my pump is pulling enough vaccum.