Johnson Fuel Only Pump

[svranjic]

Gday

got the old VRO 1 pump on my outboard which has been disconnected. Problem is with me mixing the oil in fuel it is fouling the plugs up real bad. Even at idle it soaks em. I find when trauling it soaks em so bad that it causes the plugs to miss. Not to mention poor idle with the plugs being fouled up all the time.

Have read all the info on VRO and how unreliable it is, have also read info regarding the difference it makes when disconnected regarding fouling of plugs etc.

I was wondering, If I were to remove the VRO pump completely, and install a fuel only pump would this solve the plug fouling issue???? Or is there no difference in how the VRO pump distributes fuel to that of a fuel only pump?

i.e. A pump such as this http://www.dixiemarinesales.com/detail.aspx?ID=2

I dont wanna spend $600 on new VRO kit, I am happy to premix. Just without the plugs being soaked in oil

Cheers

[Spaniard_King]

The VRO is just a fuel pump with an added oil mixing unit. After disonnecting the oil inlet line the VRO becomes a simple fuel pump therefore you wopuld gain nuthing.

Try using 95 octane unleaded and mix the oil in a litre or 2 of fuel before adding to the fuel tank.

Also a couple of things that will help. Is the engine tunned correctly ie fuel mixture settings on carbies. What plug are you using?? you can try usin a QL78YC plug as I am guessing you currently use a QL77JC4 the 78YC is a projected electrode and is less prone to fouling.

[FNQCairns]

Plug fouling is a bit of urban legend on an engine in good condition, I am with Gary. part of tcw3 specification is the lack of fouling built in, this is a minimum spec, some TCW3s will be better than others, still something is wrong, lack of thermostats even or tuning or even overdosing somewhere.

cheers fnq

[dnej]

Could you give us your specs on how you mix the fuel oil combination.,and what oil you are using.
David

[svranjic]

Cheers for replies

Am running QL77JC4 plugs. Also been putting in Penrite 2 stroke outboard oil mixed 50:1. I am measuring it exactly and usually add fresh fuel to the fuel container and then add correct amount of oil.

Have run compression test

Results:

Top cylinder 130psi

Middle cylinder 126psi

Bottom cylinder 123psi

When I replaced the air silencer gaskets the johnson dealer said something about my carbies not having adjustable needle valve screws...... I havent really looked into this as I have tried to do the simple things first.

At the moment it is idling quite high, but even still sometimes manages to cut out when at very light throttle. I have been asuming its fouled plugs due to the missing all the time after trauling. Either way when I pull the plugs out every time theyre covered in oil.

I gather that after disconnecting the vro there is nothing to adjust the amount of oil being fed at idle, so at idle when it needs say 100:1 it is getting 50:1 instead. I take it even a straight fuel only pump will not distrubute fuel any differently to my vro one considering they will both use pulse sensors to sort out how much fuel is needed.

I have notice though after using the motor i found a little bit of unburnt fuel that has leaked out of the air silencer hole and sits at bottom of engine. Its only a tiny bit but Im assuming this is from me tilting the engine back when at home. Leaking Carbie maybe?

[FNQCairns]

Cheers for replies

Am running QL77JC4 plugs. Also been putting in Penrite 2 stroke outboard oil mixed 50:1. I am measuring it exactly and usually add fresh fuel to the fuel container and then add correct amount of oil.

Have run compression test

Results:

Top cylinder 130psi

Middle cylinder 126psi

Bottom cylinder 123psi

When I replaced the air silencer gaskets the johnson dealer said something about my carbies not having adjustable needle valve screws...... I havent really looked into this as I have tried to do the simple things first.

At the moment it is idling quite high, but even still sometimes manages to cut out when at very light throttle. I have been asuming its fouled plugs due to the missing all the time after trauling. Either way when I pull the plugs out every time theyre covered in oil.

I gather that after disconnecting the vro there is nothing to adjust the amount of oil being fed at idle, so at idle when it needs say 100:1 it is getting 50:1 instead. I take it even a straight fuel only pump will not distrubute fuel any differently to my vro one considering they will both use pulse sensors to sort out how much fuel is needed.

I have notice though after using the motor i found a little bit of unburnt fuel that has leaked out of the air silencer hole and sits at bottom of engine. Its only a tiny bit but Im assuming this is from me tilting the engine back when at home. Leaking Carbie maybe?

My crystal ball says you have a tuning problem, this could be any one or a couple of things but it needs a good tune from someone who can still do it these days - link and sync etc ( get it done on new fuel (basic unleaded only) and oil) all the way to the carbs. I highly suspect your major problem will disappear, it will always start to run rough after trolling at 50:1 and may even skip a beat or two when you finally do accelerate way but it will still leave a 4 stroke behind regardless...this is normal.

Get the thermostat checked/replaced too.

cheers fnq

[Noelm]

OK, lets start at the beginning, at idle is when a "mix your own" will foul plugs the most, your post indicates that you think otherwise, simple reason is the 50:1 mix you are supplying the Engine at idle is correct for full speed, at idle you would need probably half, the state of the carbies is paramount to getting a premix motor running well, especially as because when you mix the fuel, the natural tendency is to add a bit more Oil, "just for luck", far better option for you is to spend the dollars, get the later model "VRO" fitted and be done with it, regardless of what you have heard, "self oilers" are not asking for trouble and most operate very well with regular care.

[Kero]

....better option for you is to spend the dollars, get the later model "VRO" fitted and be done with it, regardless of what you have heard, "self oilers" are not asking for trouble and most operate very well with regular care.


I agree with Noelm. I too used to be very wary/scared of the VRO pump. It wasn't until someone actually explained what they do and how they do it, did I feel comfortable with it. The VRO is a very simple and reliable pump for mixing oil and fuel. Many of the "horror" stories that you hear, are usually unfairly blamed on the VRO packing up. In most cases if a VRO were to fail, it would usually over oil. I have the later model VRO fitted and still connected. It sure beats self mixing fuel, and saves fuel going stale in the tank.

[svranjic]

Cheers for all the replies

Today I went to my local Johnson dealer to look at getting some carbie cleaner and look at getting a carbie rebuild kit. Luckily for me I was served by a mechanic who I think may have been the owner. Anyhow, He asked me what I was planning to do and why, I described my problem to him and he was nice enough to help.

Basically his advise was even with the VRO disconnected the plugs should not foul, or foul as bad as they are on my outboard. He recons there is no way in hell I should be rebuilding the carbs given that all 3 plugs are fouling. If there was only 1 plug fouling he recons yeh he would look at leaking carbie. Anyways his advice was seeing as all 3 plugs are fouling and the motor is performing fine at both high and low rpm it would indicate to him the engine is running cold. He recons if I braught it in there to be looked at and fixed they would be replacing thermostat.

So I purchased a thermostat kit and will fit tommorow. Will also be decarbing the motor, not for any reasons related to the fouling though.

So I will see how that goes, crossing my fingers. If I were to pump the fuel primer bulb and hold it tight when it gets hard, if there were carbie leaks would the bulb slowly get softer?

Anyhow thanks for all the replies this far I appreciate it and will post up results - hopefully good ones

[svranjic]

Just an update

Put the boat in the river yesterday after changing thermostat and running engine tuner through the carbies to clean out carbon deposits.

Wow what a difference, motor runs like a dream. I drove it at WOT for a bit to clear out all remaining engine tuner.

Anyhow Whilst I was out there I thought Ide better check the idle speed at rest and whilst in gear. Idle speed was set far too low, no wonder it has been stalling when faintly in gear. Put the motor in gear and set idle speed to around 850rpm.

Could not get the thing to stall after that :)

Also no missing whilst I was out. Pulled the plugs when I got home and the tips were dry. Still a bit of crap around the actual thread on the plug but im assuming thats from putting the carbie clean through. Put new plugs in today.

Seems like prob is solved. Whilst I was at it, I removed the air silencer cover and pumped the fuel bulb and held it tight - no leaks from the valve seals in any of the carbs. However If I keep pumping the bulb even whilst firm I was able to force fuel out of carbie no. 2. So I guess that could do with a rebuild some time in future when funds permit.

I think like many ppl have said those plugs are going to foul up when trauling or at idle simply because the VRO is disconnected and thus there is no oil level adjustment when idling. Am considering possibly purchasing a new VRO pump at a good price but dunno if its worth it as I have peace of mind mixing my own fuel.

Cheers for all the help! :D

[Noelm]

OK, I hate to tell you this, but spray in the carby while it is running "stuff" will not clean the carbies as they should be cleaned, they need to be dismantled and done properly, however, you seem to be happy with the results, so best leave well enough alone, and lets hope you do not get a "lean burn"

[FNQCairns]

Like Noelm said the engine tuner did not much to fix the problem, as above it was running cold, your results are from a now warm engine most probably.

The VRO would need to be a good price, I do not think you have a gummed up carbie any more than any other engine that was running cold so like crap at idle and trolling speeds, stalling/fouling plugs as a result.

The fuel out the mouth of the carb is not strictly abnormal, the pressure from the bulb is higher than the pressure from the fuel pump, this can overwhelm the needle and seat to let a little past sometimes, nothing to loose sleep over.

The carbs are your decision - if you have any problems now that can be related sensibly to dirty carbs then do it, with a warm engine the plugs will not foul on modern oil at 50:1 as above, anyone that says so is full of it or only has the experience of a poor running outboard so tarred them all with the same brush.

cheers fnq

[svranjic]

I should have clarified, I didnt put the engine tuner in with the aim of fixing the fouling of the plugs problem or specifically to clean the carbies. I put it in because I was under the impression it should be done once a yr or every service generally just to clean combustion chamber and maintain performance.

I am aware that taking apart the carbies and soaking in solvent is the only correct way to clean them.

Anyhow seems the old thermostat was buggered and engine was runnin cold. If that hasnt fixed it then out comes the carbie rebuild kits, which will probably happen soon anyways when I have some spare time.

Other than that new water pump and gear oil are next on the list. Plus hydraulic steering, new trailer, new fish finder, GPS etc etc etc etc the list goes on :-[