'89 150XP leaks fuel when squeeze primer ball. Vacumme switch? VRO air diaphragm?

[smaki]

Symptoms and Apparent Problem:
Boat began to not start reliably ? cranks over fine but will not fire. Stranded us last time out so got towed in. Noticed fuel leaking from a mostly white part on the passenger side of the engine when squeeze the primer ball before starting. Attached is a picture of the leaking white plastic part and also the side of the '89 Evinrude 150XP where it is. The fuel line doesn?t pump up rock-hard tight and hold pressure like it used to. In fact, the bulb never stays hard. The white plastic part leaks fuel from a crack toward the rear more on each pump and possibly between the bottom wires while hard to say as the fuel drips down with gravity. Cannot use primer ball to pump up to ?normal? pressure as the white part leaks on each squeeze of the primer ball. Suspect air in the line while not sure. Just a few seconds later when pump the primer ball again it is not tight holding fuel line pressure ? do recall it used to. For the many years when it started fine, once I pumped pressure in the system before starting it the pressure used to stay in the line as could be felt on the ball being hard if tried to squeeze it a few minutes later. The bottom of the vacuum switch has two wires which have some sort of wet insulation or epoxy between them falling out (the stuff that falls out the bottom feels like wet fiberglass and is brown in color).

Possible Solution:
According to ?ob? here, who is an ?Admiral? who joined iboats in Aug 2002 with many thousands of posts, ?The unit pictured with the white plastic on the bottom portion is a vacuum switch. If fuel is weeping from it when the fuel bulb is pumped up, then you likely have a ruptured air motor diaphragm in the vro pump,as it is driven by the pressure and vacuum pulses from the engine crankcase.? Want to confirm this... It seems I may have squeezed the ball too hard too much and blew out the vacuum switch and / or the air diaphragm of VRO unit. Can someone who has fixed a similar situation please let us know how? Is is possible just the vacuum switch is bad? Or is someone fairly sure it is the vro air motor diaphragm? Is there a way to test or debug? Which do I try to replace first? Can I do this myself with normal tools around from working on cars, airplanes, and dirt bikes - or is this something better left to a pro? It looks like the vacuum switch is a simple swap ? not sure about the air diaphram rebild kit for the VRO unit. Found great VRO info with history at: http://continuouswave.com/whaler/reference/VRO.html including the air motor diaphragm kit that might be needed is OMC part number 435921. Have a Clymer manual B736 for 1973 to 1990 48 to 235 HP Evinrude/Johnson Outboards while doesn?t provide direction for this. Local dealer wants $27.95 for the VRO air diaphragm rebuild kit. The vacuum switch is $129.15 and they say is being obsoleted as is not made anymore. Not sure of what are the OMC part numbers. Do not see either the vacuum switch or VRO air motor diaphragm here on iboats ? Is there another good place to buy OMC parts online or can these guys get it if I email them the part number? Confused and trying to decide how to proceed to make the fuel leak go away and keep pressure in the fuel line. Hope to again have a reliable boat and appreciate help from someone who has fixed this before.

Lesson Learned:
Be careful not to squeeze your balls too hard! Wish now I would not have.

 

[Benny1963]

Re: '89 150XP leaks fuel when squeeze primer ball. Vacumme switch? VRO air diaphrag

Re: '89 150XP leaks fuel when squeeze primer ball. Vacumme switch? VRO air diaphrag

ditch it and go premix 50 to 1

 

[smaki]

Re: '89 150XP leaks fuel when squeeze primer ball. Vacumme switch? VRO air diaphragm

Thank you for a speedy reply. Doing research and brainstorming the idea to remove VRO or figure out how to fix what broke.

Found information on how to disable the VRO at the thread: http://forums.iboats.com/showthread.php?t=258690&highlight=VRO
which says will still have the vacuum switch to indicate a 'fuel obstruction' which is the first I've heard what it does.

My vacuum switch leaks and will not hold fuel pressure and possibly allows air into my fuel line going into the VRO fuel pump. The more research I do the more it seems my vacuum switch needs to be replaced (or another option is could bypass it while knowing if there is a fuel obstruction seems a good idea). I am trying to figure out if I also need to replace the VRO air diaphragm as well based on the advice given me by 'OB" and do not know how to do that or inspect/prove if my VRO is good or not as of yet... can someone here tell me how to proceed?

Does someone have or know how to find the OMC part numbers where I can get the vacuum switch and air diaphragm rebuild kit mail-ordered (no dealer near me stocks it). Do I contact OMC directly or is there a better way to buy parts for the best prices now and in the future?


Why Not to Remove VRO:

Could reduce resale value of my boat... not that I plan to ever sell it.

To remove the VRO oiling At 50:1 pre-mix it will smoke more at idle and use more oil. It is true would not have to ever worry about a VRO oiling failure.

While would then have to make sure the horn doesn't honk and debug that as it is VERY LOUD:

(1) There is a low oil alarm ... should I keep oil tank full enough so the the horn doesn't beep or is there another simple way to disable the horn?

(2) According to http://continuouswave.com/whaler/reference/VRO.html "OMC products have the only automatic lubrication systems with a 'no oil flow' alarm. The VRO's electronic circuitry compares the RPM of the engine to the number of pressure pulses from the oil pump piston. As the oil flows into the fuel area, the pressure moves a small piston that actuates a steel pin in the alarm module. The pin's movement is detected electronically and "counted." If the engine revolutions exceed the preprogrammed oil pulse ratios, the warning horn is activated sounding a rapid on and off sequence." Do not know how to make this alarm not go off.

(3) Could be other alarms to deal with.
​

When in premix on a bigger boat will gas/oil separate? To feed less than 50:1 premix to engine would be bad. In chain saws, dirt bikes, or small outboards with pre-mix I simply give them a shake just in case once in a while. With a 2.8 liter V6 two-stroke on a 19.5 foot boat with built-in dual 15 gallon fuel tanks it is not so easy to shake as needed. Example: When filling could the oil put in sink to the bottom of the fuel and not mix properly? Example: When the boat sits for a few months in the winter will the fuel/oil separate? Do those who remove VRO find a long stir rod or mix in 5 gallon gas cans then fill the main tanks? Should I fill each main tank only two thirds so room to slosh around then slam the brakes on a few times on the way to the boat ramp?

 

[smaki]

Re: '89 150XP leaks fuel when squeeze primer ball. Vacumme switch? VRO air diaphragm

Found the vacuum switch part number at: http://shop2.evinrude.com/ext/index.aspx?s1=d620a7a2689e6ad727e4e33279455cc1

Found the VR0 air diaphragm part number at: http://continuouswave.com/whaler/reference/VRO.html in the "servicing" section.

My pump has a tag on it that says VRO2. The "factory" doesn't have it in stock and I have to contact dealers directly and it gave a list so I wrote this note ...


"From shop2.evinrude.com they say you are a dealer who currently stock this part and that I need to contact you directly for pricing, cost of shipping, and when I can have it (standard UPS Ground to zip code 97231 in Portland, OR):

Part Number: 0394937 ..........Description: VACUUM SWITCH

Also interested in seeing if you have a VRO2 air motor diaphragm kit (think this is the right one - please confirm):

Part Number: 435921 .......... Description: VRO AIR MOTOR DIAPHRAGM KIT

For 1989 150XP Evinrude outboards tag says model number: E150STLCEM

The vacuum switch leaks fuel each time I squeeze the primer ball so seems it needs to be replaced and one person advised is good to replace the air diaphragm at the same time (is this true or should I just fix the vacuum switch alone and hit the water?). The boat recently has not started reliably as it always has for over a decade and last time out had to get towed in.

If the price is right and you can get it to me soon will give you a call with my complete address and credit card so you can ship it my way without delay. Ready to go BOATIN' this summer and need the above parts as soon as can get them. Please let me know if you need any further information from me.

Thank you and kind regards ..."

 

[woody66912]

Re: '89 150XP leaks fuel when squeeze primer ball. Vacumme switch? VRO air diaphragm

it's up to you to remove or leave the vro but you should replace your vac switch when fuel line vacuum reaches 7 inches you get a horn .many v6s squeaked pistons be cause this switch was removed.

 

[smaki]

Re: '89 150XP leaks fuel when squeeze primer ball. Vacumme switch? VRO air diaphragm

Thank you Woodie! Thank you for the advice. Yes will replace my leaking vacuum switch as do not want to squeek pistons.

At this time leaning toward leaving my VRO2 oiling in place while open to removal and still doing more research. Wondering if there is a way to know if my VRO2 has a problem which took the vacuum switch out (To rebuild the air diaphragm is only something like $30 in parts while do not want to do it unless know is bad so looking if there is a way to test and know for sure). Also realize there is an anti-siphon valve in the line, a valve in the primer ball, a fuel rebuild kit available for the VRO2, and floats/valves in the carbs, that could cause the pressure to not remain in the fuel line when primed. Hoping my only problem is the vacuum switch.

Boat was not starting reliably, stranded me last time out was towed in, got pissed at it so has now sat about a year, and need to debug what is going on and get it started again so can use before summer is over. Wonder if is only my leaking vacuum switch letting air bubbles/foam into the line or not letting enough pressure to build that the carbs are primed.

PROPOSED PLAN (feedback is welcome):

Step 1: Spray a bit of starting fluid in the carbs and see if it fires. Then would know have spark and know it will fire. Would feel a bit of success and by putting fuel directly to carbs would then know the problem is somewhere in fuel delivery.

Step2: This is where I really need your help a, b, c, d, or e??? Either:

a) Without testing anything. Assume it is just the bad vacuum switch causing my situation as is clearly leaking when pump on primer ball and could be letting air into the fuel line. Wait to get a new vacuum switch installed and then see if it will run when installed (my concern is something like the VRO air diaphragm being bad will take out the new switch and cost me time and money).

b) Do research to test everything possible, try to do this the right way, and learn the most I can about this boat I plan to keep in the process (this is the mode I've been in while feel am getting a case of analysis paralysis). Find out how to test VRO2 fuel vacume/fuel output/crankcase vacuume/for leaks (crank it over then pressure test, volume test, use a vacuum gauge, or some other ways/combination). Ensure siphon valve is good (either remove from the line for temporary, take it out and blow on it, take it appart, or something). Replace my primer ball. Replace the vacuum switch. Then see if it will start and run.

c) Quickly try to move forward by temporarily removing the fuel hose from the bad and leaking vacuum switch. Then plug the open fuel line with a bolt and hose clamp. Leave the hole open to the leaky vacuum switch (or if better temporarily put hose plugged with a bolt zip-tied). Then see if the line will pump up and hold pressure as it used to. If so, if it will fire and run while realize the vacuum switch situation may cause some kind of alarm.

d) Hire a local pro possibly a local mobile boat mechanic to fix this for me and get this running.

e) Something better one of you tell me to do.
​

Step 3: Go BOATIN' !!!!

Want my boat back so will spend the time and / or money to get this fixed.

 

[woody66912]

Re: '89 150XP leaks fuel when squeeze primer ball. Vacumme switch? VRO air diaphragm

if local guy has vacuum/pressure gear case tester. while holding finger over fuel out let nipple pull 10 in of vac at air motor nipple should hold 1 min release finger should hear click do same test with pressure pump.and yes can disable vac switch while running on hose to see if starting issue goes away

 

[ezeke]

Re: '89 150XP leaks fuel when squeeze primer ball. Vacumme switch? VRO air diaphragm

Anytime fuel leaks out of the fuel system, air can also get in and run the engine lean. As stated above, the vacuum switch is a must so replace it. The VRO2 is a great premix pump if you want to use it that way. I'm still running mine that way from 1988.

I don't think that relying on the original VRO2 pump as a mixer after almost 20 years is a good idea. Upgrading to the OMS pumps is a good idea if you don't want to premix and just wait for the VRO2 to wear out.

Premixing with the VRO2 costs you nothing and that side of the pump can be repaired with a kit, so theoretically you could keep it going indefinitely with premix at a modest cost.

http://www.maxrules.com/graphics/vropics/VROflowchart.JPG

http://maxrules.com/fixomcvro.html