Motor stalls Fuel pump, VRO or Both?

[klog]

Have a 1990 200 HP evinrude. When the bulb is pumped up initially the motor will fire and idle for about 2 to 3 minutes. then it sputters and dies. If I advance the throttle it dies more quickly. After stopping it will restart immediately and then only run for 10 to 30 seconds. If I re pump the bulb it will do the exact same thing. I added oil to my fuel in the tank to keep it from overheating. (The first time it did this while on the water the overheating warning bell sounded and I beached it immediately.) The water flow through the motor is normal and it does not over heat now that I added the oil. <br />Any ideas. Could this be the VRO pump is bad and is there a seperate fuel pump besides the VRO? <br />Thanks

 

[DJ]

Re: Motor stalls Fuel pump, VRO or Both?

klog,<br /><br />Do you have any warning horns going off?<br /><br />Adding oil to the tank will not stop an overheat condition.<br /><br />I believe you have a fuel restriction.<br /><br />Look for these concerns.<br /><br />1. Is the fuel primer bulb installed correctly? Arrow pointed toward engine?<br /><br />2. Try running it from a portable fuel tank.<br /><br />3. Fuel filter/watrer seperator clooged?

 

[klog]

Re: Motor stalls Fuel pump, VRO or Both?

1. Bulb is correctly installed, <br />2. Have recently replaced the fuel water seperator with a raycor and it has worked fine. <br />3. There were warning sounds (constant beeping) when the problem first cropped up and the water out the pee hole was hotter than normal. Now that there is oil in the fuel there are no warnings and the water out is normal temperature. <br />Thanks<br />klg

 

[Solittle]

Re: Motor stalls Fuel pump, VRO or Both?

Do you still have the problem?

 

[rickdb1boat]

Re: Motor stalls Fuel pump, VRO or Both?

djohns19,<br /><br />If his VRO was not putting out an adequate oil supply, would this not cause the motor to overheat? This would also explain why when he mixed the oil himself, the overheating problem went away.

 

[ob]

Re: Motor stalls Fuel pump, VRO or Both?

klog,I'm still not clear on what alarm tone you were getting on the engine.Was it a steady tone or rapid short tones.Steady tone is overheat and rapid short tones is no oil.Is this a three wire or a four wire VRO ?Lack of vro oiling will most definately cause an engine overheat followed shortly by seizure or meltdown.

 

[klog]

Re: Motor stalls Fuel pump, VRO or Both?

Three wire VRO<br />Not short quick tones but a long tone about every second or so. <br />I also thought that since there is no tone with the oil added to the fuel in the tank that this may be VRO not getting oil and fuel mixed. <br />The question is does the VRO only mix the fuel and oil and then another fuel pump feeds the carb or does the vro mix it and then push it on to the carb? <br />Thanks for all your replys.<br />Klg

 

[ob]

Re: Motor stalls Fuel pump, VRO or Both?

klog,The vro pump is a dual function pump .One half pumps two cycle oil and the other half pumps gas.It is an air motor driven unit via crankcase pulses.A long tone every second or so sounds almost like an oxymoron and I can only assume that it was indeed the no oil alarm.The three wire vro pumps have a reputation for being unreliable as far as the alarms are concerned and has prompted many to either upgrade to the four wire or use the existing fuel half as a 50:1 pumper.This topic has come up many times on these forums and much to my surprise the vro pumps have as many diciples as many religions.My take on it is that if the alarms don't sound "before" the engine is nearing dire straits from an oil related starvation condition ,then they serve little purpose after the fact.

 

[DJ]

Re: Motor stalls Fuel pump, VRO or Both?

Rick,<br /><br />I'm thinking, fuel restriction.<br /><br />Especially if there has been a fuel line change. The V-4, V-6 OMC's need a 3/8" ID (minimum) fuel line.

 

[rickdb1boat]

Re: Motor stalls Fuel pump, VRO or Both?

My thought is that is was indeed the overheat alarm going off due to engine overheating from lack of lubrication from the VRO. As OB said, the 3 wire system is fair at best when it comes to a reliable warning. I would either find the problem with the VRO or get rid of the VRO all together. Either way, stick with the pre-mix until you decide. No sense in risking engine failure if avoidable. Personally, I would deep-six the VRO and pre-mix my own. I did!!

 

[rickdb1boat]

Re: Motor stalls Fuel pump, VRO or Both?

I hear ya djohns. But if that is so, why did the overheat situation go away when he pre-mixed? That wouldn't have solved a lean mixture problem. Or do you think it just "Masked" the real problem?

 

[DJ]

Re: Motor stalls Fuel pump, VRO or Both?

Rick,<br /><br />I do not disagree with your diagnosis, as long as everything else is OK.

 

[rickdb1boat]

Re: Motor stalls Fuel pump, VRO or Both?

This one really has me thinking. I'm now very curious as to what's going on with it. How would you find out the real cause, other than tear the VRO pump apart? Any other thoughts?

 

[klog]

Re: Motor stalls Fuel pump, VRO or Both?

It was a tone of about a second in length followed by an equal length pause and then repeat. If I replace the three wire with the four do I have to route the fourth wire to the ignition to let the VRO know that its running? <br />If the oil mixing part of the VRO is'nt working would the fuel side keep on working or does something have to be changed to have it function in this manner. If the fuel side keeps on working then why would I still be stalling out after a while. If I manually work the bulb it will stay running longer than the 2 to 3 minutes previously mentioned. It seems to me that maybe neither function is working. When I prime the bulb it forces fuel (and now fuel and oil) up into the carbs and the motor fires. It seems that it runs until all of the fuel pushed into it at priming is gone. <br />THx<br />Klog <br />I could manually mix the fuel for a while while I try to locate a replacement VRO.

 

[rickdb1boat]

Re: Motor stalls Fuel pump, VRO or Both?

That really makes me think the pump is shot. No oil, No fuel= Dead pump.

 

[DJ]

Re: Motor stalls Fuel pump, VRO or Both?

klog,<br /><br />I'm not sure about the 3 to 4 wire conversion.<br /><br />However, if the VRO fails, it typically overoils the engine-failsafe.<br /><br />I still think you have a fuel restiction. Have you checked/eliminated the fuel anti siphon valve at the fuel tank outlet?

 

[ob]

Re: Motor stalls Fuel pump, VRO or Both?

That clears the air a bit klog.That is indeed the no oil alarm.You have a problem somewhere either between the oil tank and vro pump or the oil half of the vro pump is malfuntioning.check the pickup tube in the oil reservoir for obstructions and the oil line for any air leaks that may be present.The oil line should then be primed before priming the fuel line and its bulb should pump up firm and stay firm .

 

[rickdb1boat]

Re: Motor stalls Fuel pump, VRO or Both?

How about hooking up a portable tank with pre-mix and see what happens?

 

[klog]

Re: Motor stalls Fuel pump, VRO or Both?

The fuel lines havenot been changed recently. The only change in the fuel system recently was the replacement of the old fuel water seperator with a Raycor and it seemed to run fine after that. Seems to me that if I had a fuel restriction problem I wouldn't be able to get the bulb to pump up hard at start up but I'm sort of a novice at this outboard stuff. <br />Thanks for all of your help<br />Klg

 

[klog]

Re: Motor stalls Fuel pump, VRO or Both?

Thanks OB i'll check the pick up line tomorrow. The oil bulb stays hard when pumped up and up until this problem is seemed to be using the proper amount of oil when running. <br />KLG