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Fuel issue 1992 100 hp need help!!

QUICKSILVER3682

New member
I have a 92 Johnson 100hp. At open throttle under load it completely boggs out and stalls. I finally figured out if I keep pumping the bulb while running at wide open throttle it doesnt skip a beat and runs 100 percent.
Does anyone know what the issue could be? I was thinking the pulse limiter or the whole VRO2. Its not pulling up enough fuel under load unless I keep pupming the bulb.
Maybe the fuel pump?
 
Re: Fuel issue 92 100hp need help!!

Check for bad o-rings in fuel hose connecters.-----Pull the fuel pump apart for inspection ( easier than you might think )-----there used to be repair kits available for them.
 
Re: Fuel issue 92 100hp need help!!

Thank you, I checked the lines and have new connectors. I will pull the fuel pump today amd get back to you. Do you think it would be the fuel pump before the VRO2 pump or are they one in the same? The diagram shows both.
 
Re: Fuel issue 92 100hp need help!!

Post a picture ----As far as I know there is only one pump.---------------The 88 models had a fuel only pump ( no mixing in the pump ) the others came standard with the VRO ( automatic mixing )-------------Describe the other pump in your diagram.
 
Re: Fuel issue 92 100hp need help!!

The 1992 100 hp was manufactured in several model cofigurations, all of which incorporated the fuel/oil pump VRO2 part number 175107 superseded up to part number 5007420.

There are repair kits available at your local dealership in various configurations.
 
Re: Fuel issue 92 100hp need help!!

Thank you guys for the help. I looked again and you guys were right I only have one VRO2 pump. I mix the gas inside the fuel tank myself. What I noticed today is that the electric choke that sits off to the side of the carbs and on top (electric selenoid with a red clip and valve cap on top) has two cracks by the bottom screws on the black plastic piece that has three smaller hoses going to it. When I choke it I can see gas coming out.
Could this be the prombles sucking air in ?
 
Re: Fuel issue 92 100hp need help!!

I looked it up the primer selenoid cover is what is cracked. So I guess Im wondering if that is enough to cause the problem under load..?
 
Re: Fuel issue 92 100hp need help!!

So I took off the selenoid cover and relized after inspecting it it is not cracacked just scratched but there ig gas leaking out of there and the rubber gasket is pretty worn looking so Im guessing that is the leak. but still wondering if that can be the problem.
 
Re: Fuel issue 92 100hp need help!!

also does the red piece need to be a certain way because when u spin it seems to let the holes inside the cover be open and does fuel come out of the valve at all (top) when you prime it ?
 
Re: Fuel issue 92 100hp need help!!

The red piece needs to be a certain way.------------The primer is electric but it can be operated manually as well ( good design that )-----There is an O-ring in there that may be leaking.-----------If the primer lever is wrong the motor will flood.--------------------To get back to the poor running , you need to start with a compression test. It is the first step in trouble shooting !!--------Do you have an owners manual or service manual for your motor.
 
Re: Fuel issue 92 100hp need help!!

Fuel will not come out of that top valve. Regardless of whether that fuel leak is contributing to your problem or not, it requires correcting if for not other reason to eliminate it as a problem.

(Fuel Primer Solenoid Function)
(J. Reeves)

The RED lever...... The normal operating/running position is to have that red lever positioned over top of the solenoid and aimed at the other end of the solenoid, gently turned to its stop. This is the normal/automatic mode position. Pushing the key in opens the valve within the solenoid allowing fuel to pass thru it in order to prime and start the engine. Looking upon this solenoid as a electric choke results in a better understanding of it.

Having that red lever turned in the opposite direction, facing away from the solenoid, allows fuel to flow thru it to the crankcase area. One would only turn the red lever to this position in a case where the battery might go dead and the engine had to be started via the rope pull method. Look upon putting the red lever in this position as moving a choke lever on a choke equipped engine to the full closed position. Either one would supply fuel to the crankcase/engine for starting purposes BUT if left in that position while running would flood the engine.

The later model primer solenoids are equipped with a schrader valve, used for attaching a pressurized can of fogging oil etc, available at your local dealership with complete instructions.

Pumping the fuel primer bulb up hard fills the carburetor float chambers of course, but that process also applies fuel pressure to the primer solenoid.
The two small hoses leading from the primer solenoid branch off via tees to each fuel manifold section that would feed fuel to the individual cylinders.
Pushing the key in activates the primer solenoid to allow fuel to flow thru it to the intake manifold passageways. Cranking the engine over causes the fuel pump to engage which in turn sends fuel pulses to the primer solenoid via the 3/8" fuel hose.
Some engines incorporates the "Fast Start" feature which automatically advances the spark electronically so no advance of the throttle is required for starting.
Engines that do not have the "Fast Start" feature will be required to have the throttle advanced slightly.
Starting procedure: pump fuel bulb up hard, crank engine and push the key in at the same time. When the engine fires/starts, release the key so that it falls back to the run position.
Bottom line..... Look upon the primer solenoid as an electric choke.

Thousands of parts in my remaining stock. Not able to list them all. Let me know what you need and I'll look it up for you. Visit my eBay auction at:

http://shop.ebay.com/Joe_OMC32/m.html?_dmd=1&_ipg=50&_sop=12&_rdc=1
 
Re: Fuel issue 92 100hp need help!!

Thank you, The red lever has been pointing away from the selenoid. The compression,plugs,wires, and coils ect.. have all been checked. The motor was rebuilt a few years back and it was serviced 6 months back and just recently the bulb wont stay hard and it dies out under load.Like I said before if I slowly keep pumping the bulb it runs perfect for as long as I pump it. We ran it miles. Do You think the red clip being ponting away from the selenoid is flooding and cause of the problem. or do I need to replace the VRO2.
I really appreciate the help.. I have rebuilt cars and dirtbikes my whole life so I understand it all very well but outboards are a bit different for me when trouble shooting..
 
Re: Fuel issue 92 100hp need help!!

Quicksilver, I had a very similar problem. My outboard would run fine except WOT. At WOT it would start to bog down. If I pumped the bulb it would keep going. It ended up being a small screen filter in the fuel tank pick up that was partially clogged. I cleaned it out and the problem disapeared

Scott
 
Re: Fuel issue 92 100hp need help!!

I think you need to pull the VRO apart for inspection.-------------easy to do, --------All the joints are sealed with o-rings.---------------Now the pump is run by crankcase pressure pulses and you need to check that as well.------------Remove the bypass cover for the cylinder that runs the VRO and look at piston and rings.
 
Re: Fuel issue 92 100hp need help!!

No, I have no parts for that unit. Re-read my original reply post #11 (position of red lever).
 
Re: Fuel issue 92 100hp need help!!

Scott thanks for that info. I wish That was my problem. I did that frist and I even bought a small fuel tank to bypass all that to check.
 
Re: Fuel issue 92 100hp need help!!

Thanks Joe , Today I will try to reseal the primer cover and reposition the red lever as you posted. and get back to you . If not I will pull the VRO2 and check it out. I believe cylinder four is the pulse cylinder for the fuel. Is that correct and I don't have a manuel yet so which one would that be if I'm standing behind the boat and motor looking at the bow.

Thank you gain for all your help and time. I really appreciate everything from everyone.

Bill K
 
Re: Fuel issue 92 100hp need help!!

Bottom cylinder, lower left.-----------Pull the bypass cover .----------------Will only cost a $1.00 gasket at most.
 
Re: Fuel issue 92 100hp need help!!

Ok thanks, Iwill be doing all that today and see what I come up with. What is the normal compression supposed to be on those cylinders. Would the compression be low if there was a problem with the pulse cylinder.?
 
Re: Fuel issue 92 100hp need help!!

There is crankcase compression and cylinder compression ---------the cylinder compression can be good , while crankcase compression ( which drives the VRO ) can be poor.------------Crankcase compression depends on condition of piston and rings , reed valves, crankshaft seal rings and the lower crankshaft seal.----------We often see people throwing expensive parts at a motor, only to report that motor " still runs the same " --------------inspection and trouble shoooting is the way to proceed.
 
Re: Fuel issue 92 100hp need help!!

GREAT THANKS... Im gonna get started so Hopefully I can get it fixed soon to get my son out on the boat.. That's all he wants to do at four years old... Gotta Love it.. I will let you know Thanks again.
 
Re: Fuel issue 92 100hp need help!!

Standing in back of engine, facing spark plugs, the cylinders are numbered as follows.

2....1
4....3
 
Re: Fuel issue 92 100hp need help!!

Thank you, I took the VRO2 apart and everything looks really good inside in good shape. Didnt see any signs of leaking and diaphram looks great too. I resealed the primer cover and while putting the cover back on the nipple cracked off the small left one with the two little hoses. Guess Im SOL till I find another one. But I did adjust the red clip back to normal mode till it stopped and I wonder if that could be one of the issues because I am certain that it has been pointing out with this whole problem. What does the left little hose go to on that primer. Looks like the carb.?
 
Re: Fuel issue 92 100hp need help!!

When cranking to start, you push the key in to activate the primer , fuel under pressure is then sprayed directly into the airflow going into the engine. This is a far better setup than choke flappers.----------------These nipples break off all the time and most dealers keep replacement covers in stock.
 
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