Jonhson 40hp vro fuel problem? please help

[leotzian]

Hi friends
I have posted in the past again and you had helped me for all the problems I had.

Now I have this problem
I have a Jonhson 40hp 1996 vro engine

The truth is that I use this engine not very often
I have a stange problem to me it seams it is fuel problem, you know much better

My engine on the console in the rpm instrument, it has four leds to check the engine like no oil, low oil ,hot, etc, all the leds are off , when I switch the engine on, the buzzer, and the alarm leds make the usually routine, all on and then one by one goes off.

When I use the engine in low speed about 2000- 2500 rpm 7-10 miles I have no problem.

When I have the engine full throttle 4000-5000 rpm 22- 27 miles ( it is on a 4 meters boat ) it is running very smooth, and after 3 to 6 minutes suddenly it seams that the engine has no gas, and it is starting to stop. and after a while it stoppes. When I try to start it it won't start easilly, I have to press the bulb on the tank, press the choke , and after 2 minutes it is running again very nice
I remind you the alarm leds are always of ( no alarm )

When the problem starting to happen, when I use the trottle from idle to max sometimes I have in max trottle and the rpm of the engine doen't increase

It seams to me that it is fuel problem, and when the engine needs more fuel in 4500-5000 rpm causes the problem

The oil is in a separate tank, the spark plugs are new, nom leaks in the engine ( oil or fuel )

Can anyone help?

Thank you in advance
Leonidas

 

[tashasdaddy]

Re: Jonhson 40hp vro fuel problem? please help

is the vent clear and open on the fuel tank? is the hose completely, properly connected to the motor. looks like a built in tank, do you have a fuel/water separator. old gas?

have you check compression and spark on both cylinders?

 

[leotzian]

Re: Jonhson 40hp vro fuel problem? please help

My friend thanks for the answer

It is an extenal about 25 litres tank the one that came with the motor.
The air vent of the tank is ok, I have tried it with the cap open, the hose is ok, no leakage, if I disconnect the fuel line in the exit of the fuel filter, and press the tank's bulb a lot of fuel is comming out of the fuel filter.

I have not checked the compression, but I have changed the spark plugs
I had not put exact the same type, but there are exact the same.( Japan made )

The motor is from 1996 but it has very few hours of use

How do you explain that for 5 - 6 minutes the engine runs perfect in full power 5500 rpm giving me about 28 miles of speed, if there was compession problem the motor it was difficult to run like this

 

[leotzian]

Re: Jonhson 40hp vro fuel problem? please help

Thank you all

 

[Rscardina]

Re: Jonhson 40hp vro fuel problem? please help

the best way to tell if the pump is bad is..when the engine is running and starts to feel like you are slowing...pump the fuel bulb and see if it picks back up again. if the motor continues to run and run good when you keep pressing the bulb then the fuel pump is having issues.

if the bulb is hard when she dies then something else is going on.

 

[leotzian]

Re: Jonhson 40hp vro fuel problem? please help

I tried this I throttled the motor in full about 4500 rpm, and I was pressing the fuel bulb every 1 minute , I had to press one or 2 times to get hard. but the problem still occured, when I pressed the choke button sometimes in the keys of the engine the problem seemed to get better
I don't know whar to search for..

What you suppose to be the problem? Perhaps to clean the carbs?

 

[Rscardina]

Re: Jonhson 40hp vro fuel problem? please help

I tried this I throttled the motor in full about 4500 rpm, and I was pressing the fuel bulb every 1 minute , I had to press one or 2 times to get hard. but the problem still occured, when I pressed the choke button sometimes in the keys of the engine the problem seemed to get better
I don't know whar to search for..

What you suppose to be the problem? Perhaps to clean the carbs?

if you pumped till hard..and it stays hard then i would look for carb issues. buy kits, take them apart and clean them good.

if you choke it at it ran better than you definitely were not getting enough fuel..usually if you choke and carbs are good..engine will stall from too much fuel.

so check out the carbs first..and let us know what you find.

 

[leotzian]

Re: Jonhson 40hp vro fuel problem? please help

Thank you all
I will check and clean the carbs , I will put the boat into the sea and tell you the news

 

[chadpcb]

Re: Jonhson 40hp vro fuel problem? please help

Just a side note.

You do know that if there is an issue with heat, fuel or oil. The engine will slow down on its own trying to prevent damage to the motor. If you are using premix gas instead of the VRO make sure you are mixing 50:1 ratio or 16oz oil to 6 gallons of fuel. Make sure you check your warning buzzer for proper operation.

 

[leotzian]

Re: Jonhson 40hp vro fuel problem? please help

Just a side note.

You do know that if there is an issue with heat, fuel or oil. The engine will slow down on its own trying to prevent damage to the motor. .

If it was heat or oil the motor has alarm hot, oil, no oil, check engine. No alarm is activated , thats why I believe it is fuel problem

The horn, and the alarm leds are ok in the self test that the engine does when you switch the key on

If the safety system acticates ( S.L.O.W ) It have beeps and led on, and the engine runs till 1500-2000 rpm
Mine is switches off like it has no gas

 

[leotzian]

Re: Jonhson 40hp vro fuel problem? please help

Hi all again
I am coming to tell you what I have done after all your advices

I changed fuel line from the tank, changed spark plugs, changed all fuel lines in the motor, cleaned the carbs ( there was ok I found no problem) disabled VRO disconnected oil line, closed the line, disconected the cables from the vro and from the tank, and I mixed the gas with oil 50:1
Checked everything, no leaks of fuel.

I checked the motor out of the water in a barrel it was all ok.
then I put the boat in the sea.

The problem still exist but a little different
In idle the motor sounds ok, my boat is 4 meters with 2 persons in when I was putting the throttle at full position the boat was almost at once inreasing speed until 4500 rpm ( 25-28 miles speed )
Now it seams that it has not the power that used to had, it makes more time to increase speed, and the sound it is not continious the same, it seems that the rpm are not stable, ( It is not very easy to discribe and my English are not so good ), when I press the choke the motor getting better and the rpm are rising, All this time I press the tanks primer bulb and it is firm meaning the carbs are full of fuel.
The engine is not stopping I can use it, but I remember that the throttle after the middle, it was giving the motor a lot of power and now is not.
How can I check if a cylinder is not working ok, or a carb is not working ok, can I do anything? ( Perhaps half of the engine is not working ok, I don't know )
When I disconnect one spark plug what it will happen?
Is there a possibility that it is electonic ignition problem?
Do you have an idea how I check all these out of the water?


I dont know what is going on I have cleaned the carbs, I disabled the vro ( I was shure that it was vro problem but it wasn't ).

I don't know where to look and search, and the problem is that when I have the boat out of the water at my house, I cannot check this because it must have load and put the throtlle to full to check.....

Another question, inside the motor the plastic part that is mooving from the throttle on the console , mooves the flaps of the carbs ( if i say correctly ) and also some joints that goes on the upper part of the engine, ( under the spinning part )what are they doing?
Is there advance in this engine can I regulate something else?( I don't know the terms to descibe )

I hope you had understand me, sorry for my English

Thank you in advance
Leonidas

 

[Rscardina]

Re: Jonhson 40hp vro fuel problem? please help

sounds like you are on the right track. If you push the choke in and the engine getts better, then it is most likely a fuel issue still. I know you say you have rebuilt the carbs already but you may want to go through it again and make sure everything is clean.
Also, where the carbs mount to the throttle plate there are several passages that fuel needs to come out of and they may be dirty...so again go through and check the carbs one more time and make sure the small holes on the throttle plates are clear as well.

 

[leotzian]

Re: Jonhson 40hp vro fuel problem? please help

This motor will get me crazy
I opened the carbs and I cleaned them carefully, there were very clean already, I checked the passages...,with compressed air, and with fuel, I don't know what to think, those carbs are very simple...
Please explain saying " where the carbs mount to the throttle plate" where exactly?

As you something
Lets assume that the fuel pumb is not working, If I continiusly press the tank's bulb, is not the same thing?, the motor should working ok, is that correct or not??

The truth is that mice had get in the motor, cut me some cables, and fuel lines, but I have soldered the cables correctly, and changed all the lines......, The engine if you look at it it seams as brand new.

I do my work,the engine is running, the sound seems to go up and down a little,difficult to describe is working, it is not stopping, but it seams it had lost power,
but I checked a lot of times pressing the choke the engine the time of pressing seams ok,( increases rpm ) and later the same thing, very stange, if I disconnect the spark plug, the engine how it will sound?, I am wondering is both carbs or cylinders work the same...

Another question, inside the motor the plastic part that is mooving from the throttle on the console , mooves the flaps of the carbs ( if i say correctly ) and also some joints that goes on the upper part of the engine, ( under the spinning part )what are they doing?

 

[Rscardina]

Re: Jonhson 40hp vro fuel problem? please help

This motor will get me crazy
I opened the carbs and I cleaned them carefully, there were very clean already, I checked the passages...,with compressed air, and with fuel, I don't know what to think, those carbs are very simple...
Please explain saying " where the carbs mount to the throttle plate" where exactly?

As you something
Lets assume that the fuel pumb is not working, If I continiusly press the tank's bulb, is not the same thing?, the motor should working ok, is that correct or not??

The truth is that mice had get in the motor, cut me some cables, and fuel lines, but I have soldered the cables correctly, and changed all the lines......, The engine if you look at it it seams as brand new.

I do my work,the engine is running, the sound seems to go up and down a little,difficult to describe is working, it is not stopping, but it seams it had lost power,
but I checked a lot of times pressing the choke the engine the time of pressing seams ok,( increases rpm ) and later the same thing, very stange, if I disconnect the spark plug, the engine how it will sound?, I am wondering is both carbs or cylinders work the same...

Another question, inside the motor the plastic part that is mooving from the throttle on the console , mooves the flaps of the carbs ( if i say correctly ) and also some joints that goes on the upper part of the engine, ( under the spinning part )what are they doing?

the carbs mount to a large plate with holes (this is called the throtle body). each carb sits over a hole that has the butterfly( these open and close when you push the control up and down) the butterfly's attach to rods that are controlled by the arms you see on top near the fylwheel.. if when you go full the plates are open and when you go to neutral the plates close..this is good.

when you push the control to full, the butterfly's open to let more air and fuel in.

the carb has 4 bolts yes? these bolts attach to the large plate, each plate has 2 carbs?.. ok, so if you look at the gasket on the back of the carb it has 2 circles. where there circles line up on the plate are holes. these holes need to be clean as well, not just carb.

if you have problems with power at high speed then the carb orifice inside the bowl may be getting clogged. If you push the key in and choke, and the engine responds with higher rpm's then it is a fuel issue. somewhere it is slowing down or not getting to the engine fast enough.

if you want to test this,,take the back cover off so you see the carbs. start the engine and when you hear the up and down..try to spray fuel/oil mix into the carb..one at a time and see which one makes the engine pick up rpm. the ones that make it run better when you spray are the ones that have problems.

 

[leotzian]

Re: Jonhson 40hp vro fuel problem? please help

Hi my friend, thanks for the detailed answer
I think my carbs and my engine is not exactly as you say
It is a 40HP 1996 Johnson engine 2 cylinders 2 carbs
The carbs are mounted on the engine with 2 nuts each
In the front of the carbs there is a black plate that each is screwed with 3 screws they get air from there.
The baterflyes are in the carbs and when I trottle with the joystick, both butterflies move the same, in idle there are closed, and in the full trottle there are full open parallel to the ground. I will take some pictures of my carbs and put them here,now I will sent you some pictures from my engines user manual

The rod I was asking what is doing is the rod in the yellow frame
With those photos you see how my carbs are.
The red markings shows the rod that controlls the butterflies that are inside the carbs.

 

[chadpcb]

Re: Jonhson 40hp vro fuel problem? please help

The rod you have indicated in the picture with the yellow around it is the controller arm for you timerbase. The timerbase controls the function of the advance spark.

 

[leotzian]

Re: Jonhson 40hp vro fuel problem? please help

The rod you have indicated in the picture with the yellow around it is the controller arm for you timerbase. The timerbase controls the function of the advance spark.

Hi my friend
Is there a way to check if this rod is well adjusted?
My problem I had described in the thread may be related to this rod?
I had never touched this rod

 

[chadpcb]

Re: Jonhson 40hp vro fuel problem? please help

This motor will get me crazy
I opened the carbs and I cleaned them carefully, there were very clean already, I checked the passages...,with compressed air, and with fuel, I don't know what to think, those carbs are very simple...
Please explain saying " where the carbs mount to the throttle plate" where exactly? Here is what he is talking about.

As you something
Lets assume that the fuel pumb is not working, If I continiusly press the tank's bulb, is not the same thing?, the motor should working ok, is that correct or not?? If you are pressing the primer bulb and the motor smooths out and runs correctly the yes your fuel pump is bad.

The truth is that mice had get in the motor, cut me some cables, and fuel lines, but I have soldered the cables correctly, and changed all the lines......, The engine if you look at it it seams as brand new.

I do my work,the engine is running, the sound seems to go up and down a little,difficult to describe is working, it is not stopping, but it seams it had lost power,
but I checked a lot of times pressing the choke the engine the time of pressing seams ok,( increases rpm ) and later the same thing, very stange, if I disconnect the spark plug, the engine how it will sound?, I am wondering is both carbs or cylinders work the same...If you use the choke and the motor smooths out and runs properly then you are still having fuel proplems.

Another question, inside the motor the plastic part that is mooving from the throttle on the console , mooves the flaps of the carbs ( if i say correctly ) and also some joints that goes on the upper part of the engine, ( under the spinning part )what are they doing?Ok your spinning part is known as the flywheel. The arm directly under is the control arm for the timerbase, it controls the advance spark.

I have added information to your post.

 

[leotzian]

Re: Jonhson 40hp vro fuel problem? please help

My friend thank you for your help

1)
"As you something
Lets assume that the fuel pumb is not working, If I continiusly press the tank's bulb, is not the same thing?, the motor should working ok, is that correct or not?? If you are pressing the primer bulb and the motor smooths out and runs correctly the yes your fuel pump is bad."

So I press the bulb continiusly and the problem still occurs meaning it is not pump problem

2)I might have fuel problems as you say


3) "Ok your spinning part is known as the flywheel. The arm directly under is the control arm for the timerbase, it controls the advance spark."
Is there a way to check if the this control arm is well regulated?

4)Perhaps the high speed jets are my problem, I will take the carbs out again and with your diagram I will pay detailed attention.

Thanks for all everybody for help

 

[leotzian]

Re: Jonhson 40hp vro fuel problem? please help

Hi my friend

Looking to your carb diagram I had never cleaned High speed jet
I had never checked 19, 4, 12, 33 parts and the 8 and 18

I will clean the carbs again this diagram is very helpful

Thanks