VRO Problems on 87 Johnson 40Hp

adc

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Nov 18, 2005
Messages
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I recently purchased this motor and would appreciate some help. I am told by previous owner that it is a 1987 model. Hope that is correct.<br />
40hp-10.jpg
<br /><br />Previous owner suggested I do away with VRO feature and just mix gas/oil. So, for past few days I have searched internet and this forum for advise on doing away with the VRO system....and found lots of varied opinions.<br /><br />Today I pluged off the oil inlet to motor, hooked up the gasline and pumped the bulb......PROBLEMS.....<br />Immediately gasoline started coming out of the top side of the fuel pump...see pic.<br /><br />
40hp-11.jpg
<br /><br />Needless to say, I did not start the motor and would like advise on my options at this point.<br /><br />I assume I could have pump rebuilt, but I still do not want to utilize the VRO feature as I do not have the oil tank.<br /><br />Can a conventional OMC fuel pump be used as was used on early and mid-eighties motors...? Other options would be....?<br /><br />One other thing...the correct Champion sparkplug for this motor would be....? I went to parts store to buy 2 new plugs and they could not find numbers for this motor so I just bought 2 more like were in it...but would like to be sure of correct sparkplug number.<br /><br />Would appreciate any advice and comments. If anyone has specific part numbers for a conversion away from VRO system, that would really be a help.<br /><br />Thanks!
 

MCM

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Re: VRO Problems on 87 Johnson 40Hp

Yep its a 1987 40hp Johnson, a new pump BMC p/n 0438556 runs about $50.00, rebuild kit p/n 0398514 about $20.00 or so.<br /><br />Here's some posts on the VRO.<br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=36;t=000010 <br /><br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=36;t=000028 <br /><br />You can use the search feature for more info on disconnecting, just type in VRO disconnect and select the subject only option.
 

adc

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Re: VRO Problems on 87 Johnson 40Hp

Thanks for the information,<br /><br />
...new pump BMC p/n 0438556 runs about $50.00...
Excuse my not knowing...but is that BMC as in "Bombardier" ........? :)
 

MCM

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Re: VRO Problems on 87 Johnson 40Hp

That would be them ;)
 

adc

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Re: VRO Problems on 87 Johnson 40Hp

Thanks for the information. I have removed VRO pump, installed conventional fuel pump and re-plumbed fuel lines as per pic below.<br /><br />I used existing fuel line block from old VRO system but wonder about the middle hose running behind starter and to other side of engine. I cannot see for sure, but I think it goes to choke selenoid and I left it intact.... <br />Would this be correct...?<br /> <br />I tried starting motor...did not start. Guess carbs will come off next for cleaning.<br /><br />Any clarification about that middle fuel line will be appreciated....Thanks!<br /><br />
40hp-9.jpg
 

ob15

Chief Petty Officer
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Jan 4, 2004
Messages
514
Re: VRO Problems on 87 Johnson 40Hp

Are you sure the carbs are getting fuel? Try squirting some premix into the carb and see if it starts. That would indicate a fuel supply problem. Also, if you can get it to start that way, try using the primer (explained below) to see if you can keep it running. You will probably just have to bump it every couple of seconds. <br /><br />The middle line goes the the primer. OMC didn't use chokes then. It is basically a little pump that squirts fuel behind the throttle plates instead of a choke to suck fuel form the carb bowls.<br /><br />You can do a search for "primer" & it will probably turn up tons of posts.
 

OBJ

Supreme Mariner
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Dec 27, 2002
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10,161
Re: VRO Problems on 87 Johnson 40Hp

Just a couple things on the "not starting" problem.....<br /><br />Make sure you have spark on both cylinders and make sure the emergency stop switch has it's key in place. <br /><br />You may also consider a service manual for the engine. The OEM manuals are preferred.
 

adc

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Nov 18, 2005
Messages
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Re: VRO Problems on 87 Johnson 40Hp

Thanks for all the help. <br /><br />Rebuilt both carbs today. They really were a mess...lots of dried up junk in bottom of both bowls.<br /><br />There seems to be plenty of fire at spark plugs...Checked fire at both.<br /><br />And motor cranks over well.....but....all I get is an occassional "back fire" through the exhaust, smoke and ugly greasy wet spot on the driveway....Pretty frustrating.... :( <br /><br />Sure don't want to...but dealer may be next visit.
 

andy6374

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Messages
1,617
Re: VRO Problems on 87 Johnson 40Hp

Fuel, Fire....Do you have compression?
 

TxShorty

Petty Officer 3rd Class
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Oct 28, 2005
Messages
84
Re: VRO Problems on 87 Johnson 40Hp

You might check for a sheared flywheel key as well...<br /><br />Does it run squirting fuel into the carbs?
 

MCM

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Re: VRO Problems on 87 Johnson 40Hp

A couple of causes of backfire are air/vacuum leak such a bad head or exhaust gasket, vacuum/fuel line etc. also a lean fuel situation, might want to double check the carb and fuel pump work to start with.
 

andy6374

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Re: VRO Problems on 87 Johnson 40Hp

As to the lean situation MCM mentioned. Check that the throttle shutters in the carb throats are fully close at idle, if not it will spit and sputter all day long
 

adc

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Nov 18, 2005
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Re: VRO Problems on 87 Johnson 40Hp

Well..........GOOD NEWS....!!<br /><br />Just by chance a friend of mine asked if I was sure top coil wire was going to top spark plug and like wise bottom to bottom plug. Double checked and yes, that was OK.<br /><br />But....the backfiring...sounds like a timing thing..right? So I just took plug wire from top coil and put it on bottom spark plug and spark plug wire from bottom coil to top spark plug.<br /><br />Motor STARTED immediately at the slightess turn of the key!! <br /><br />As I said at top of thread, I just recently got this motor from a friend who had not run it in several years. Looks like someone had played some games with the wires feeding the coils... ;) <br /><br />I will sleep well tonight!<br /><br />Thanks to all of you for help on this....definitely learned several things and got a little lucky too. :)
 

OBJ

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Dec 27, 2002
Messages
10,161
Re: VRO Problems on 87 Johnson 40Hp

Take a look at the leads from the power pack to the coils. The top lead will have a blue stripe. The bottom will have a green stripe. Just remember "Blue sky" (up)....."Green Grass" (down). Can't go wrong.
 
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