99 johnson 115 outboard losing fuel pressure after sitting

[mschviuz]

The motor cranks easy and idles good but when I get on the throttle it bogs and I have to prime the bulb. Then I get back on the throttle and it runs fine sometimes and other times I have to prime the bulb again( maybe 2-3) times. After I go through this process I can run for hours without any problems until I stop for an extended period of time and then I'm back to where I started. It's losing fuel pressure in the line; the bulb won't be close to being hard. Can someone please help? The local shop tells me the vro needs to be replaced, but I'm not so sure about that since the motor runs good except after sitting

 

[heimskr]

Re: 99 johnson 115 outboard losing fuel pressure after sitting

I had the same problem on my 90 150 and replacing the fuel line on it helped a whole lot!
It still does it on occasion but for the most part it took care of the problem.
The VRO could be getting wore out and have a small leak somewhere in a seal or something too. I know I'm debating on replacing the VRO on mine but so far I can live with the occasional issue.

 

[mschviuz]

Re: 99 johnson 115 outboard losing fuel pressure after sitting

I had the same problem on my 90 150 and replacing the fuel line on it helped a whole lot!
It still does it on occasion but for the most part it took care of the problem.
The VRO could be getting wore out and have a small leak somewhere in a seal or something too. I know I'm debating on replacing the VRO on mine but so far I can live with the occasional issue.

I replaced the fuel line between the hull and motor and bulb last year and it seems to have fixed the problem last year. The first couple times out this year it ran fine and now it's back to its old antics! It's doing this almost every time I stop for an hour or more.

I just want to be sure there isn't something else I can do or is there a way to check the vro pump to be sure that is the problem before I spend the money on a new one?

 

[mschviuz]

Re: 99 johnson 115 outboard losing fuel pressure after sitting

I think I'm going to remove the vro pump and check for wear of the diaphram, etc. I've read where some say to rebuild and others say buy new pump. Big difference in price between those two options so if anyone has any suggestions please let me know.

I guess my biggest question is can the pump be the problem and it still run fine except after sitting for a while. I always thought that once the pump goes bad it won't run at all.

 

[mschviuz]

Re: 99 johnson 115 outboard losing fuel pressure after sitting

anybody?

 

[mschviuz]

 

[ezeke]

Re: 99 johnson 115 outboard losing fuel pressure after sitting

I would say that you have an air leak in your system and possibly some obstruction as well. Start by keeping steady pressure on the primer bulb and carefuully inspecting the system all the way to the engine. Look for any sign of wetness; if fuel can get out, air can get in.

Check the OMS pump as well, It's always possible that the diaphragm is ruptured. The instructions should be in your factory service manual, or check with Bill Kelly at Maxrules.com. He sells the rebuild kits and has most of the instructional material on his website.

 

[mschviuz]

Re: 99 johnson 115 outboard losing fuel pressure after sitting

I would say that you have an air leak in your system and possibly some obstruction as well. Start by keeping steady pressure on the primer bulb and carefuully inspecting the system all the way to the engine. Look for any sign of wetness; if fuel can get out, air can get in.

Check the OMS pump as well, It's always possible that the diaphragm is ruptured. The instructions should be in your factory service manual, or check with Bill Kelly at Maxrules.com. He sells the rebuild kits and has most of the instructional material on his website.

Ok I will check for fuel leaks again and I'm going to go ahead and replace the zip ties with hose clamps.

I don't think I have an obstruction because I have replaced the fuel filter and when I had it off, I squeezed the bulb a couple of times and it pumped fuel out easily.

I was reading on maxrules about disassembling the pump earlier. thanks....hopefully I find the problem soon.

 

[mschviuz]

Re: 99 johnson 115 outboard losing fuel pressure after sitting

Ok..was holding pressure on the prime bulb and heard what sounded like a leak(finally got to check all this with no kids around and it was quiet!) That's when I noticed the manual valve(red with schrader valve on end). It was in the 3 o clock position. I turned it to 12 o clock and the bulb fully compressed and gas came out of the carbs. Then I turned it clockwise down to 6 o clock and that seems to have shut it completely. Now I can prime the bulb and it gets solid and I'm not seeing or hearing any leaks. I hope this does it.....I guess that red valve accidently got opened half way or vibrated to that point; I'm not sure

 

[ezeke]

Re: 99 johnson 115 outboard losing fuel pressure after sitting

Sounds right. The red handle should be aligned with the cylindrical base for normal operation.

 

[Greenporter]

Re: 99 johnson 115 outboard losing fuel pressure after sitting

I have a similar problem with a tough start after sitting for an hour after running and starting great.

Any update on this?

 

[mschviuz]

Re: 99 johnson 115 outboard losing fuel pressure after sitting

I replaced the vro pump and that took care of the problem

 

[Demko87]

I am having the same issue with my 115, but my vro is bypassed so I mix gas. Was it the primer tab that was leaking?

 

[GA_Boater]

I am having the same issue with my 115, but my vro is bypassed so I mix gas. Was it the primer tab that was leaking?

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