1995 Johnson 150hp Ocean Runner - Fuel Problem

[speeddiesel]

Hi guys, looking for any common failures or any advise on where to begin please

1995 Johnson 150hp Ocean Runner on the back of 17" Glastron.

Bought it 2 years ago, very clean problem free engine for many hours now, fresh engine build, pumps, gaskets, carbs all new... but seller opted to not use the vro2 system and pre-mix 50:1??? last weekend I started to develop a slight mis-fire that slowly got worse over the weekend. Then turned into sudden power losses at cruising speed, rough idle and stalling. It is clearly starving for fuel, I pump the ball and it is good again for 30 seconds, I got a friend to pump the ball every 10-15 seconds or so and got it 45 minutes back to the launch no problem???

I am assuming it is fuel pump related but not sure if is the disconnected VRO2 pump now causing issues or the fuel pump or something simple like I was told a "diaphragm". Spoke to 3 marine shops today, got 3 different answers lol. I do plan to get the VRO2 oil system working again this winter, which I meant to last year but the boat ran so good I did not want to fix what was not broken. The advice I got on here was that I should get it working again but 50:1 in the tank would not hurt the vro2 pump?

Thanks in advance for any helps guys
Dave

[boobie]

I'm confused. Is the vro pump still on it?? Are you now mixing 50:1 fuel?? Are you still using the remote oil tank in the boat ??

[SparkieBoat]

you either need a new fuel pump..or your fuel line/connectors are sucking air, or your bulb is restricting your fuel, I assume you have fresh clean filters.

[speeddiesel]

Thanks for the quick reply, sorry if I was unclear, that vro pump is on still but the oil tank is disconnected, yes mixing 50:1 in the tank.

Are the balls common failure, could it be that simple? Clean fuel filter, same problem with fuel cap off but have not changed/tested ball or lines, lines appear like new but I guess that is my starting point. Was thinking past that if no leaks detected and ball checks out ok. The local mechanic talked me into ordering a common failure "fuel pump" for about $100 looking at the diagram now it looks like I ordered a vapor pump and a long-shot that is my issue?

I see a lot of fuel components on the component bracket... The bracket consists of a reservoir tank/float valve assembly, internal fuel passages, and mounting surfaces for other related components. The fuel primer valve, fuel filter, VRO2 pump, vacuum pump and fuel vacuum warning switch are all mounted to the bracket but no "fuel pump"

Insuring the ball and lines check out were do I go, would any of these fuel related components be considered "common failure" and tested/replaced first?

Another reputably shop is saying without doubt "I am not supplying oil via the vro pump (pre mixing) and my vro pump is failing, cut to the chase and order $500 vro pump and be done with it" which are on back order. Can anyone confirm the not using the oil tank (pre-mixing) is a vro pump killer?

Excuse my ignorance I am a diesel engine expert, even moderate some diesel forums but am struggling a bit with this marine engines "basic" fuel system lol and local shops differing advise. In BC the summers are short but beautiful, would like to get a couple more weekends in a know the boats good for spring

Thanks again....
Dave

[SparkieBoat]

the VRO pump is a very very common part to FAIL. I have replaced many many of them. you can order the newer style pumps which are supposed to be better, but I still seem to be finding many of them failing also. The $100 pump will most likely not supply enough fuel for a V-6, the option to use that kind of pump can be done but you need 2 of them. here is a site that you can order a new VRO pump from for about $400, http://www.maxrules.com/fixomcvro.html I got the one with no oil side and continued to premix on my personal motor (5007422) or you can rebuild your fuel side with the kit and continue to premix, or get a new one with oil side and go back to oil injection.

[speeddiesel]

Great reply and link Sparkie... gonna replace the primer ball, check lines again tonight and will post my results. Regardless I will be ordering the new VRO2 Pump set up for pre-mix soon, it would be on order already if it could get here for this weekend but Florida is almost as far as it gets from B.C. on this continent

Thanks again, updates to come...
Dave

[speeddiesel]

Replaced the ball and eliminated the lines as the problem, tested again and still starving for fuel. Convinced it is the the VRO2 pump as was getting ready to pull the trigger on one of THESE before talking to a shop that recommends running 50:1 in the both the fuel tank and 2 stroke tank and run a new OE "unmodified" vro2 pump. Seem like a PITA but has anyone heard of or had experience with this option?

What are you opinion on the modified pumps http://www.maxrules.com/fixomcvro.html ..... reliable?

Last question, when I was testing tonight I noticed when the engine started to starve for fuel it was smoking pretty heavy white smoke, is that normal? It was the normal blue hazy look until it started starving and the engine seem a tad warm but not to were you could not hold your hand on it... yes the muffs were on.

Thanks once again...

[SparkieBoat]

I am not sure what a modified pump is. but you should get either part # 5007422 and continue to premix or part # 5007420 and reconnect your oil lines and tank and start using that and quit premixing. or you could rebuild the fuel side only and continue to premix. you could also get the old style pumps parts # 393870 upper and 438559 lower and you would have to know how to connect them, but they could work. I am not sure of any other options. I recommend the first option unless you just hate premixing then go with second option.

[speeddiesel]

I assumed p/n 5007422 was a modified version of whats on there now.

Ordering the pump or fuel side rebuild kit, is the rebuild difficult or do you recommend just getting the new pump... if it were you?

[SparkieBoat]

if the pump housing is in good condition, you can rebuild, it is not hard. a lot of the older VROs begin to just break apart, i have seen some that I would not rebuild, but most are ok.