98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy)

[c6mcfall]

1998 115 (E115SLECM) that bought the boat about 3 moths ago. The boat had sat for years. I?ve drained the tank, replaced all the fuel lines from tank to engine, new primer bulb, plugs, + I?ve rebuilt the carb?s and replaced the inline filter and added new 10 micron filter. Even after this I had issue with the primer bulb getting firm, turned out to be loose hoses on the vapor separator (?). I think I?ve finally eliminated all the lose connections, pumps up firm. Seems though I have a fuel restriction or bad fuel pump mabybe? Took it out today with a test tank and it ran better (would run over 4000 RPM) but started again with the starvation at full throttle. I wanted to eliminate the fuel tank and isolate the issue to the motor. When I rebuilt the carbs I did so by the manual and adjusted the float arm so the float was within.8mm.. Could this be causing my lean condition at high RPM?

How can I test the fuel side of the VRO? I did test the oil side tested out fine, including alarms.

Any help would be appreciated.

Thanks,
Fred

 

[schematic]

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy)

Added 10 micron filter not necessary on carbed system. OEM filter is all you need. Adding a water separator is more beneficial.

Do a fuel pressure test by adding in a fuel pressure gauge. Take it for a buzz and watch the fuel pressure when bogging. Also check the suction side for vacuum to eliminate supply restrictions.....anti-syphon valve, tank screen, etc.

 

[Boss Hawg]

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy)

Basicly having the same problem on similar motor--
http://forums.iboats.com/johnson-evinrude-outboards/1987-johnson-110-bogging-down-mid-throttle-622320.html
Making me crazy too :facepalm:
I'll keep a watch here too----

 

[c6mcfall]

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy)

Just for clarification the 10 micron filter that I added is a fuel/water separate with filter. Apologies up front for the long post..

I did some testing in the driveway on earmuffs (could not get out..). I add a section of clear tubing with a “T” fitting and added a vacuum gauge right before the fuel filter inlet on the VRO assembly.

1st Test - Connected to the fuel tank/fuel water separator I was getting ~ 3 hg vacuum and air bubbles. Disconnected the fuel supply from the fuel/oil inlet nipple and bypassed it to the “T”. Still connected to the fuel tank/fuel water separator. Now not seeing bubbles, ~ 2 hg of vacuum. Still though every now and then I get a loss of fuel in the clear tube, vacuum does not increase then fuel fills up?

2nd Test – Disconnect @ the fuel/water separator and go directly to test tank (no fuel filter/water separator) just before the built in filter. No bubbles but every now and then I get a loss of fuel in the clear tube. Vacuum ~ less than 1 hg. Then it fills back up.

3rd Test – Add a fuel pressure gauge on one side of the fuel lines coming out of the vapor separator. I am still connected to the test tank, now I’m seeing fuel pressure @ 4PSI at idle but every once in a while it will drop to 0 and then come back up.. (I also and seeing CRAP floating OUT of the vapor separator.. Same observation on fuel inlet, once in a while I get a loss of fuel then it fills back up (still just at idle) but NO loss in vacuum (how can that be??)

4th Test same as 3rd Test but connected back to the build in tank + fuel/water separator. Fuel pressure @ 2 PSI (drops to 0 every once in a while..) and I still get ~ 2hg vacuum and I get a loss of fuel then it fills back up (still just at idle) again no loss in vacuum.. and I still see crap floating out of the vapor separator (nothing visible floating in the inlet side).

So I am thinking I should replace the fuel/oil inlet nipple, seems to be a source of air getting in. I think I should also just replace ALL the fuel lines on the engine + ALL clamps with OEM snap style. (I did replace most all clamps but not with the OEM snap style). The Primer solenoid, basically all internal parts and same with the vacuum separator.

Disassemble and clean the freshly rebuilt carbs..

What about the pulse limiter, could this be the cause of the "once in a while" loss of fuel then it fills back up"??

 

[Faztbullet]

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy)

The fuel pump does not operate constantly like the old diaphragm types, it will pulse and you will see fuel pressure rise and fall as the air motor has to overcome spring tension in VRO pump. Fuel pressure shold not fall below 2-3 psi with gauge held level at fuel outlet fitting on VRO. I would remove and clean vapor separator and pull throttle manifold bodies and clean screens that supply fuel to carbs..

 

[schematic]

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy)

2nd Test – Disconnect @ the fuel/water separator and go directly to test tank (no fuel filter/water separator) just before the built in filter. No bubbles but every now and then I get a loss of fuel in the clear tube. Vacuum ~ less than 1 hg. Then it fills back up.

wouldn't hurt to try an external tank and see if bogging subsides. You may have a bad pickup tube in the onboard tank that is leaking air in.

 

[Chris1956]

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy)

Gee, Check the antisiphon valve in the fuel tank. Make sure the main strainer (under the airbox) is not leaking air or gasoline.

 

[c6mcfall]

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy)

Thanks for explaining the fuel pump, that was driving me nuts.. Nowhere does it talk about that in the manual and I could find NOTHING on-line..

Checked >> anti siphon valve in the fuel tank. Make sure the main strainer (under the airbox) is not leaking air or gasoline. << Tight and no visible sign of leaks.

I'll try and pull the pickup tube out after work, never done that before but looks straight forward enough.. Boat is a 98 Proline 170, hopefully not too bad to remove it. I was leery about trying to remove it, heard horror stories of breaking off the fittings..

Later this week I will start to remove and clean vapor separator and pull throttle manifold bodies and clean screens that supply fuel to carbs..

 

[c6mcfall]

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy)

I did with the external tank and it did.. Just not as bad..

 

[HenryB]

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy)

I’d be careful with the pickup tube. It doesn’t sound to me to be the problem. The tank isn’t that old. If it were the problem the auxiliary supply would have caught it. Ok if it unscrews easy but leave it alone if it is stuck hard or gives you a hard time. And if it does come out without a problem you should probably replace it before putting it back.

Have you done the fuel mix squirt yet at each cylinder while under way, plus squeezing the primer bulb when under way?

 

[c6mcfall]

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy)

Tube came out without issue, was surprisingly clean. Check-valve is good as well. After I put it back I was thinking "why am I putting this back..." I will pull it back out and get a new one, cheap insurance.. I actually put an open-end wrench/box combo on it from the top so the top of the box wrench was above deck, stuck a large screw driver in the box end to use as a "T" wrench.. Came right out!

Vapor separator is next..

>> Have you done the fuel mix squirt yet at each cylinder while under way, plus squeezing the primer bulb when under way?

I have not, in fact I'm not familiar with this at all?

 

[HenryB]

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy)

Remove the carburetor cover to expose the carburetor throats.

Get a squirt bottle and fill it with premixed gas.

Get the motor to stall and squeeze the primer bulb to see if that stops the stall, if not squirt the premix into each carburetor throat to see if that fixes anything.

 

[c6mcfall]

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy)

Got home to late to take it out to try this >> Have you done the fuel mix squirt yet at each cylinder while under way, plus squeezing the primer bulb when under way?

I wanted to inspect the vapor separator so I pulled the cover and found there was no gasket.. I took the float off to inspect the needle and seat and the needle was not attached to the float.. (did not leak that I saw while on the trailer but who knows under load out on the water..)

I unscrewed the vapor pump because I wanted to inspect the diaphragm and of course the springs popped out.. I only saw (2) and I think I got how it goes back together but the manual I have does not have an exploded view. (New diaphragm $2.97, new vapor pump $109.00.. Needless to say I'm eager to get it back together correctly)

Does anyone have a diagram, found a picture in a search but they didn’t’ cover the assembly. http://forums.iboats.com/johnson-evinrude-outboards/looking-vapor-pump-assembly-gaskets-460367.htm

Just want to be sure I got all the pieces and that I assemble it correctly once I get the replacement diaphragm.

Also, don’t see they sell gaskets, just the main diaphragm? And it looks like there is a very small pinhole in the diaphragm I have..

 

[midsized johnson]

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy)

I don't see a picture of the diaphragm assembly that includes springs in my repair manual (I have a 98 like yours but the manual is for a 95 model, which is the same basic platform, but may have some minor differences).
The cover to the fuel vapor separator should have an o-ring "spaghetti gasket." They sell these at your local OMC parts dealer. Don't overtighten the cover as it will distort and this can cause an air leak. The book says to tighten in an "x" pattern to 18-24 inch pounds.
Also from the book:
The float should be parallel with the separator cover, the book says to adjust float drop with the vapor separator cover in normal position, the drop dimension to the bottom of the float should be between 1-1/4 to 1-11/32 inches.

 

[Chris1956]

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy)

Try the crowleymarine web site parts catalog. It may show you how it goes back together.

 

[c6mcfall]

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy)

Try the crowleymarine web site parts catalog. It may show you how it goes back together.

I tried there as well, no luck.. Any easy way for me to test it out once I get diaphragm and assemble it?

 

[c6mcfall]

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy)

I don't see a picture of the diaphragm assembly that includes springs in my repair manual (I have a 98 like yours but the manual is for a 95 model, which is the same basic platform, but may have some minor differences).
The cover to the fuel vapor separator should have an o-ring "spaghetti gasket." They sell these at your local OMC parts dealer. Don't overtighten the cover as it will distort and this can cause an air leak. The book says to tighten in an "x" pattern to 18-24 inch pounds.
Also from the book:
The float should be parallel with the separator cover, the book says to adjust float drop with the vapor separator cover in normal position, the drop dimension to the bottom of the float should be between 1-1/4 to 1-11/32 inches.

Thanks for looking, I will check the float.

 

[c6mcfall]

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy)

called around nobody had the diaphragm, will have to order it. Anyone know how to find out what's in this OMC kit 5031812 VAPR SEP.KIT 70'99 ?

 

[c6mcfall]

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy) update

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy) update

I replaced the needle and seat on the VST and put a gasket on (was not one before). I also replaced the diaphragm on the Vapor Pump and I think I got it back together correctly.. I pumped the primer ball, no leaks and it pumped up hard.

I went back in to get a wrench, came back out and I noticed a small amount of fuel coming out of the nipple of the top of the Vapor Pump (see photo) should this be? I know the hose routs to a fitting on the block and the air shroud so I thought it might be to dump fuel?

I didn't start it because I was not sure if fuel should be coming out of here or not..

 

[slzpe]

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy) - SAME, ME TOO

Re: 98 115 (E115SLECM) Fuel Delivery Issues (driving me crazy) - SAME, ME TOO

Have you solved this problem? I have it, and it is driving me nuts also. If you did, please respond with what you think the true culprit was. Thank you.